From 1bce41ad2962bc75a675a479b70dc9c815904b68 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=8C=83=E5=BC=BA=E5=BC=BA?= <787203167@qq.com>
Date: Wed, 7 Sep 2022 18:54:18 +0800
Subject: [PATCH 1/2] =?UTF-8?q?=E4=BF=AE=E6=94=B9=E7=A6=85=E9=81=93?=
 =?UTF-8?q?=E5=B7=B2=E7=9F=A5bug?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../components/documentDataComparison.vue     | 36 ++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/jero-web/src/views/documentTools/documentComparison/components/documentDataComparison.vue b/jero-web/src/views/documentTools/documentComparison/components/documentDataComparison.vue
index 51876de9c..6ee645982 100644
--- a/jero-web/src/views/documentTools/documentComparison/components/documentDataComparison.vue
+++ b/jero-web/src/views/documentTools/documentComparison/components/documentDataComparison.vue
@@ -51,6 +51,7 @@
                     </div>
                     <div class="detail-content-content-right-data-text" v-html="item.itemsText"></div>
                   </div>
+                  <JLoading :loading="loadingText">{{$t('dataLoading')}}</JLoading>
                 </div>
               </div>
             </div>
@@ -143,7 +144,7 @@
 </template>
 
 <script>
-  import { postAction, putAction } from '../../../../api/manage'
+  import { postAction, putAction, getAction } from '../../../../api/manage'
 
   export default {
     name: 'documentDataComparison',
@@ -152,6 +153,7 @@
         formInline: {},
         formInlineText: {},
         dataLoadingText: '',
+        loadingText:false,
         rules: {
           comment: [
             {
@@ -322,6 +324,7 @@
           detailLeft[num].classList.add('detail-content-content-right-data-color')
         }
         this.dataLeft = item
+        this.dataLeft.numIndex = num
         if (this.isMatching) {
           let detailRightColor = document.getElementsByClassName('detail-content-content-right-data-color-right')
           if (detailRightColor && detailRightColor.length > 0) {
@@ -335,6 +338,8 @@
               detailRight[item.targetStand].classList.add('detail-content-content-right-data-color-right')
               detailContent[0].scrollTop = detailRight[item.targetStand].offsetTop - 150
             }
+            this.dataRight.numIndex = item.targetStand
+            this.clauseComparison()
           }
         }
       },
@@ -352,6 +357,7 @@
           detailRight[num].classList.add('detail-content-content-right-data-color-right')
         }
         this.dataRight = item
+        this.dataRight.numIndex = num
         if (this.isMatching) {
           let detailLeftColor = document.getElementsByClassName('detail-content-content-right-data-color')
           if (detailLeftColor && detailLeftColor.length > 0) {
@@ -359,15 +365,34 @@
           }
           if (item.targetStand > -1) {
             this.dataLeft = this.resultData.textLeft[item.targetStand]
+            this.dataLeft.numIndex = item.targetStand
             let detailContent = document.getElementsByClassName('detail-content-content-right-top')
             let detailLeft = document.getElementsByClassName('detail-content-content-right-data')
             if (detailLeft && detailLeft.length > 0 && item.targetStand >= 0) {
               detailLeft[item.targetStand].classList.add('detail-content-content-right-data-color')
               detailContent[0].scrollTop = detailLeft[item.targetStand].offsetTop - 150
             }
+            this.clauseComparison()
+            // this.resultData = { ...this.resultData }
           }
         }
       },
+      clauseComparison() {
+        let query = {
+          leftId: this.dataLeft.id,
+          rightId: this.dataRight.id
+        }
+        this.loadingText = true
+        getAction('/compare/sarFileCompareItem/clauseComparison', query).then((res) => {
+          if (res.success) {
+            this.loadingText = false
+            this.resultData.textLeft[this.dataLeft.numIndex].itemsText = res.result[0]
+            this.resultData.textRight[this.dataRight.numIndex].itemsText = res.result[1]
+          }else{
+            this.loadingText = false
+          }
+        })
+      },
       onSelectLeft(selectedKeys, exports) {
         let node = exports.node.$vnode.data.props.dataRef
         let detailLeft = document.getElementsByClassName('detail-content-content-right-data')
@@ -642,4 +667,13 @@
     border: 1px red solid;
   }
 
+  ::v-deep .delClass {
+    background: #ff7168;
+    font-weight: 700;
+  }
+
+  ::v-deep .insertClass {
+    background: rgba(85, 183, 255, .6);
+    font-weight: 700;
+  }
 </style>
\ No newline at end of file

From d59ebd0f2c0f890a5c235a9592202400b997b7bd Mon Sep 17 00:00:00 2001
From: gaosong <gaosong@syxysoft.com>
Date: Wed, 7 Sep 2022 18:55:17 +0800
Subject: [PATCH 2/2] =?UTF-8?q?=E4=BF=AE=E6=94=B9=E6=96=87=E6=A1=A3?=
 =?UTF-8?q?=E5=AF=B9=E6=AF=94-=E6=9D=A1=E7=9B=AE=E5=AF=B9=E6=AF=94?=
 =?UTF-8?q?=E9=AB=98=E4=BA=AE?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../SarFileCompareItemController.java         |   12 +
 .../service/ISarFileCompareItemService.java   |    2 +
 .../impl/SarFileCompareItemServiceImpl.java   |   10 +
 .../jero/modules/compare/utils/DiffUtils.java | 2312 +++++++++++++++++
 4 files changed, 2336 insertions(+)
 create mode 100644 jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/utils/DiffUtils.java

diff --git a/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/controller/SarFileCompareItemController.java b/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/controller/SarFileCompareItemController.java
index 9b0576cf6..1a179e5d7 100644
--- a/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/controller/SarFileCompareItemController.java
+++ b/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/controller/SarFileCompareItemController.java
@@ -167,4 +167,16 @@ public class SarFileCompareItemController extends JeroController<SarFileCompareI
         return super.importExcel(request, response, SarFileCompareItem.class);
     }
 
+	 /**
+	  * 条款对比高亮
+	  */
+	 @AutoLog(value = "文档对比信息条款表-条款对比高亮")
+	 @ApiOperation(value="文档对比信息条款表-条款对比高亮", notes="文档对比信息条款表-条款对比高亮")
+	 @GetMapping(value = "/clauseComparison")
+	 public Result<?> clauseComparison(@RequestParam(name="leftId",required=true) String leftId,
+									   @RequestParam(name="rightId",required=true) String rightId) {
+		 List<String> res = sarFileCompareItemService.clauseComparison(leftId,rightId);
+		 return Result.OK(res);
+	 }
+
 }
diff --git a/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/service/ISarFileCompareItemService.java b/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/service/ISarFileCompareItemService.java
index fcb412cc1..a5eba2554 100644
--- a/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/service/ISarFileCompareItemService.java
+++ b/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/service/ISarFileCompareItemService.java
@@ -72,4 +72,6 @@ public interface ISarFileCompareItemService extends IService<SarFileCompareItem>
     List<SarFileCompareItem> queryListByInfoId(String infoId);
 
     Map<String, SarFileCompareItem> queryMapByInfoId(String infoId);
+
+    List<String> clauseComparison(String lid,String rid);
 }
diff --git a/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/service/impl/SarFileCompareItemServiceImpl.java b/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/service/impl/SarFileCompareItemServiceImpl.java
index ea36ff75e..09001946b 100644
--- a/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/service/impl/SarFileCompareItemServiceImpl.java
+++ b/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/service/impl/SarFileCompareItemServiceImpl.java
@@ -6,6 +6,7 @@ import com.jero.modules.compare.entity.SarFileCompareItem;
 import com.jero.modules.compare.mapper.SarFileCompareItemMapper;
 import com.jero.modules.compare.service.ISarFileCompareItemService;
 import com.jero.modules.compare.utils.CompareConst;
+import com.jero.modules.compare.utils.DiffUtils;
 import com.jero.modules.system.util.StringUtils;
 import org.springframework.stereotype.Service;
 
@@ -122,4 +123,13 @@ public class SarFileCompareItemServiceImpl extends ServiceImpl<SarFileCompareIte
         }
         return resMap;
     }
+
+    @Override
+    public List<String> clauseComparison(String lid, String rid) {
+        SarFileCompareItem leftItem = this.queryById(lid);
+        SarFileCompareItem rightItem = this.queryById(rid);
+        DiffUtils dmp = new DiffUtils();
+        List<String> htmlDiffStr = dmp.getHtmlDiffStr(leftItem.getItemsText(), rightItem.getItemsText());
+        return htmlDiffStr;
+    }
 }
diff --git a/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/utils/DiffUtils.java b/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/utils/DiffUtils.java
new file mode 100644
index 000000000..649c82785
--- /dev/null
+++ b/jero-boot/jero-boot-modules/src/main/java/com/jero/modules/compare/utils/DiffUtils.java
@@ -0,0 +1,2312 @@
+package com.jero.modules.compare.utils;
+
+
+import java.io.UnsupportedEncodingException;
+import java.net.URLDecoder;
+import java.net.URLEncoder;
+import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class DiffUtils {
+    // Defaults.
+    // Set these on your diff_match_patch instance to override the defaults.
+
+    /**
+     * Number of seconds to map a diff before giving up (0 for infinity).
+     */
+    public float Diff_Timeout = 1.0f;
+    /**
+     * Cost of an empty edit operation in terms of edit characters.
+     */
+    public short Diff_EditCost = 4;
+    /**
+     * The size beyond which the double-ended diff activates.
+     * Double-ending is twice as fast, but less accurate.
+     */
+    public short Diff_DualThreshold = 32;
+    /**
+     * At what point is no match declared (0.0 = perfection, 1.0 = very loose).
+     */
+    public float Match_Threshold = 0.5f;
+    /**
+     * How far to search for a match (0 = exact location, 1000+ = broad match).
+     * A match this many characters away from the expected location will add
+     * 1.0 to the score (0.0 is a perfect match).
+     */
+    public int Match_Distance = 1000;
+    /**
+     * When deleting a large block of text (over ~64 characters), how close does
+     * the contents have to match the expected contents. (0.0 = perfection,
+     * 1.0 = very loose).  Note that Match_Threshold controls how closely the
+     * end points of a delete need to match.
+     */
+    public float Patch_DeleteThreshold = 0.5f;
+    /**
+     * Chunk size for context length.
+     */
+    public short Patch_Margin = 4;
+    /**
+     * The number of bits in an int.
+     */
+    private int Match_MaxBits = 32;
+
+    /**
+     * Internal class for returning results from diff_linesToChars().
+     * Other less paranoid languages just use a three-element array.
+     */
+    protected static class LinesToCharsResult {
+        protected String chars1;
+        protected String chars2;
+        protected List<String> lineArray;
+
+        protected LinesToCharsResult(String chars1, String chars2,
+                                     List<String> lineArray) {
+            this.chars1 = chars1;
+            this.chars2 = chars2;
+            this.lineArray = lineArray;
+        }
+    }
+    //  DIFF FUNCTIONS
+    /**
+     * The data structure representing a diff is a Linked list of Diff objects:
+     * {Diff(Operation.DELETE, "Hello"), Diff(Operation.INSERT, "Goodbye"),
+     *  Diff(Operation.EQUAL, " world.")}
+     * which means: delete "Hello", add "Goodbye" and keep " world."
+     */
+    public enum Operation {
+        DELETE, INSERT, EQUAL
+    }
+    /**
+     * Find the differences between two texts.
+     * Run a faster slightly less optimal diff
+     * This method allows the 'checklines' of diff_main() to be optional.
+     * Most of the time checklines is wanted, so default to true.
+     * @param text1 Old string to be diffed.
+     * @param text2 New string to be diffed.
+     * @return Linked List of Diff objects.
+     */
+    public LinkedList<Diff> diff_main(String text1, String text2) {
+        return diff_main(text1, text2, true);
+    }
+    /**
+     * Find the differences between two texts.  Simplifies the problem by
+     * stripping any common prefix or suffix off the texts before diffing.
+     * @param text1 Old string to be diffed.
+     * @param text2 New string to be diffed.
+     * @param checklines Speedup flag.  If false, then don't run a
+     *     line-level diff first to identify the changed areas.
+     *     If true, then run a faster slightly less optimal diff
+     * @return Linked List of Diff objects.
+     */
+    public LinkedList<Diff> diff_main(String text1, String text2, boolean checklines) {
+        // Check for equality (speedup)
+        LinkedList<Diff> diffs;
+        if (text1.equals(text2)) {
+            diffs = new LinkedList<Diff>();
+            diffs.add(new Diff(Operation.EQUAL, text1));
+            return diffs;
+        }
+        // Trim off common prefix (speedup)
+        int commonlength = diff_commonPrefix(text1, text2);
+        String commonprefix = text1.substring(0, commonlength);
+        text1 = text1.substring(commonlength);
+        text2 = text2.substring(commonlength);
+        // Trim off common suffix (speedup)
+        commonlength = diff_commonSuffix(text1, text2);
+        String commonsuffix = text1.substring(text1.length() - commonlength);
+        text1 = text1.substring(0, text1.length() - commonlength);
+        text2 = text2.substring(0, text2.length() - commonlength);
+        // Compute the diff on the middle block
+        diffs = diff_compute(text1, text2, checklines);
+
+        // Restore the prefix and suffix
+        if (commonprefix.length() != 0) {
+            diffs.addFirst(new Diff(Operation.EQUAL, commonprefix));
+        }
+        if (commonsuffix.length() != 0) {
+            diffs.addLast(new Diff(Operation.EQUAL, commonsuffix));
+        }
+        diff_cleanupMerge(diffs);
+        return diffs;
+    }
+    /**
+     * Find the differences between two texts.  Assumes that the texts do not
+     * have any common prefix or suffix.
+     * @param text1 Old string to be diffed.
+     * @param text2 New string to be diffed.
+     * @param checklines Speedup flag.  If false, then don't run a
+     *     line-level diff first to identify the changed areas.
+     *     If true, then run a faster slightly less optimal diff
+     * @return Linked List of Diff objects.
+     */
+    protected LinkedList<Diff> diff_compute(String text1, String text2,boolean checklines) {
+        LinkedList<Diff> diffs = new LinkedList<Diff>();
+        if (text1.length() == 0) {
+            // Just add some text (speedup)
+            diffs.add(new Diff(Operation.INSERT, text2));
+            return diffs;
+        }
+        if (text2.length() == 0) {
+            // Just delete some text (speedup)
+            diffs.add(new Diff(Operation.DELETE, text1));
+            return diffs;
+        }
+        String longtext = text1.length() > text2.length() ? text1 : text2;
+        String shorttext = text1.length() > text2.length() ? text2 : text1;
+        int i = longtext.indexOf(shorttext);
+        if (i != -1) {
+            // Shorter text is inside the longer text (speedup)
+            Operation op = (text1.length() > text2.length()) ?
+                    Operation.DELETE : Operation.INSERT;
+            diffs.add(new Diff(op, longtext.substring(0, i)));
+            diffs.add(new Diff(Operation.EQUAL, shorttext));
+            diffs.add(new Diff(op, longtext.substring(i + shorttext.length())));
+            return diffs;
+        }
+        longtext = shorttext = null;  // Garbage collect.
+        // Check to see if the problem can be split in two.
+        String[] hm = diff_halfMatch(text1, text2);
+        if (hm != null) {
+            // A half-match was found, sort out the return data.
+            String text1_a = hm[0];
+            String text1_b = hm[1];
+            String text2_a = hm[2];
+            String text2_b = hm[3];
+            String mid_common = hm[4];
+            // Send both pairs off for separate processing.
+            LinkedList<Diff> diffs_a = diff_main(text1_a, text2_a, checklines);
+            LinkedList<Diff> diffs_b = diff_main(text1_b, text2_b, checklines);
+            // Merge the results.
+            diffs = diffs_a;
+            diffs.add(new Diff(Operation.EQUAL, mid_common));
+            diffs.addAll(diffs_b);
+            return diffs;
+        }
+        // Perform a real diff.
+        if (checklines && (text1.length() < 100 || text2.length() < 100)) {
+            checklines = false;  // Too trivial for the overhead.
+        }
+        List<String> linearray = null;
+        if (checklines) {
+            // Scan the text on a line-by-line basis first.
+            LinesToCharsResult b = diff_linesToChars(text1, text2);
+            text1 = b.chars1;
+            text2 = b.chars2;
+            linearray = b.lineArray;
+        }
+        diffs = diff_map(text1, text2);
+        if (diffs == null) {
+            // No acceptable result.
+            diffs = new LinkedList<Diff>();
+            diffs.add(new Diff(Operation.DELETE, text1));
+            diffs.add(new Diff(Operation.INSERT, text2));
+        }
+        if (checklines) {
+            // Convert the diff back to original text.
+            diff_charsToLines(diffs, linearray);
+            // Eliminate freak matches (e.g. blank lines)
+            diff_cleanupSemantic(diffs);
+            // Rediff any replacement blocks, this time character-by-character.
+            // Add a dummy entry at the end.
+            diffs.add(new Diff(Operation.EQUAL, ""));
+            int count_delete = 0;
+            int count_insert = 0;
+            String text_delete = "";
+            String text_insert = "";
+            ListIterator<Diff> pointer = diffs.listIterator();
+            Diff thisDiff = pointer.next();
+            while (thisDiff != null) {
+                switch (thisDiff.operation) {
+                    case INSERT:
+                        count_insert++;
+                        text_insert += thisDiff.text;
+                        break;
+                    case DELETE:
+                        count_delete++;
+                        text_delete += thisDiff.text;
+                        break;
+                    case EQUAL:
+                        // Upon reaching an equality, check for prior redundancies.
+                        if (count_delete >= 1 && count_insert >= 1) {
+                            // Delete the offending records and add the merged ones.
+                            pointer.previous();
+                            for (int j = 0; j < count_delete + count_insert; j++) {
+                                pointer.previous();
+                                pointer.remove();
+                            }
+                            for (Diff newDiff : diff_main(text_delete, text_insert, false)) {
+                                pointer.add(newDiff);
+                            }
+                        }
+                        count_insert = 0;
+                        count_delete = 0;
+                        text_delete = "";
+                        text_insert = "";
+                        break;
+                }
+                thisDiff = pointer.hasNext() ? pointer.next() : null;
+            }
+            diffs.removeLast();  // Remove the dummy entry at the end.
+        }
+        return diffs;
+    }
+    /**
+     * Split two texts into a list of strings.  Reduce the texts to a string of
+     * hashes where each Unicode character represents one line.
+     * @param text1 First string.
+     * @param text2 Second string.
+     * @return An object containing the encoded text1, the encoded text2 and
+     *     the List of unique strings.  The zeroth element of the List of
+     *     unique strings is intentionally blank.
+     */
+    protected LinesToCharsResult diff_linesToChars(String text1, String text2) {
+        List<String> lineArray = new ArrayList<String>();
+        Map<String, Integer> lineHash = new HashMap<String, Integer>();
+        // e.g. linearray[4] == "Hello\n"
+        // e.g. linehash.get("Hello\n") == 4
+        // "\x00" is a valid character, but various debuggers don't like it.
+        // So we'll insert a junk entry to avoid generating a null character.
+        lineArray.add("");
+        String chars1 = diff_linesToCharsMunge(text1, lineArray, lineHash);
+        String chars2 = diff_linesToCharsMunge(text2, lineArray, lineHash);
+        return new LinesToCharsResult(chars1, chars2, lineArray);
+    }
+    /**
+     * Split a text into a list of strings.  Reduce the texts to a string of
+     * hashes where each Unicode character represents one line.
+     * @param text String to encode.
+     * @param lineArray List of unique strings.
+     * @param lineHash Map of strings to indices.
+     * @return Encoded string.
+     */
+    private String diff_linesToCharsMunge(String text, List<String> lineArray,
+                                          Map<String, Integer> lineHash) {
+        int lineStart = 0;
+        int lineEnd = -1;
+        String line;
+        StringBuilder chars = new StringBuilder();
+        // Walk the text, pulling out a substring for each line.
+        // text.split('\n') would would temporarily double our memory footprint.
+        // Modifying text would create many large strings to garbage collect.
+        while (lineEnd < text.length() - 1) {
+            lineEnd = text.indexOf('\n', lineStart);
+            if (lineEnd == -1) {
+                lineEnd = text.length() - 1;
+            }
+            line = text.substring(lineStart, lineEnd + 1);
+            lineStart = lineEnd + 1;
+
+            if (lineHash.containsKey(line)) {
+                chars.append(String.valueOf((char) (int) lineHash.get(line)));
+            } else {
+                lineArray.add(line);
+                lineHash.put(line, lineArray.size() - 1);
+                chars.append(String.valueOf((char) (lineArray.size() - 1)));
+            }
+        }
+        return chars.toString();
+    }
+    /**
+     * Rehydrate the text in a diff from a string of line hashes to real lines of
+     * text.
+     * @param diffs LinkedList of Diff objects.
+     * @param lineArray List of unique strings.
+     */
+    protected void diff_charsToLines(LinkedList<Diff> diffs,
+                                     List<String> lineArray) {
+        StringBuilder text;
+        for (Diff diff : diffs) {
+            text = new StringBuilder();
+            for (int y = 0; y < diff.text.length(); y++) {
+                text.append(lineArray.get(diff.text.charAt(y)));
+            }
+            diff.text = text.toString();
+        }
+    }
+    /**
+     * Explore the intersection points between the two texts.
+     * @param text1 Old string to be diffed.
+     * @param text2 New string to be diffed.
+     * @return LinkedList of Diff objects or null if no diff available.
+     */
+    protected LinkedList<Diff> diff_map(String text1, String text2) {
+        long ms_end = System.currentTimeMillis() + (long) (Diff_Timeout * 1000);
+        // Cache the text lengths to prevent multiple calls.
+        int text1_length = text1.length();
+        int text2_length = text2.length();
+        int max_d = text1_length + text2_length - 1;
+        boolean doubleEnd = Diff_DualThreshold * 2 < max_d;
+        List<Set<Long>> v_map1 = new ArrayList<Set<Long>>();
+        List<Set<Long>> v_map2 = new ArrayList<Set<Long>>();
+        Map<Integer, Integer> v1 = new HashMap<Integer, Integer>();
+        Map<Integer, Integer> v2 = new HashMap<Integer, Integer>();
+        v1.put(1, 0);
+        v2.put(1, 0);
+        int x, y;
+        Long footstep = 0L;  // Used to track overlapping paths.
+        Map<Long, Integer> footsteps = new HashMap<Long, Integer>();
+        boolean done = false;
+        // If the total number of characters is odd, then the front path will
+        // collide with the reverse path.
+        boolean front = ((text1_length + text2_length) % 2 == 1);
+        for (int d = 0; d < max_d; d++) {
+            // Bail out if timeout reached.
+            if (Diff_Timeout > 0 && System.currentTimeMillis() > ms_end) {
+                return null;
+            }
+
+            // Walk the front path one step.
+            v_map1.add(new HashSet<Long>());  // Adds at index 'd'.
+            for (int k = -d; k <= d; k += 2) {
+                if (k == -d || k != d && v1.get(k - 1) < v1.get(k + 1)) {
+                    x = v1.get(k + 1);
+                } else {
+                    x = v1.get(k - 1) + 1;
+                }
+                y = x - k;
+                if (doubleEnd) {
+                    footstep = diff_footprint(x, y);
+                    if (front && (footsteps.containsKey(footstep))) {
+                        done = true;
+                    }
+                    if (!front) {
+                        footsteps.put(footstep, d);
+                    }
+                }
+                while (!done && x < text1_length && y < text2_length
+                        && text1.charAt(x) == text2.charAt(y)) {
+                    x++;
+                    y++;
+                    if (doubleEnd) {
+                        footstep = diff_footprint(x, y);
+                        if (front && (footsteps.containsKey(footstep))) {
+                            done = true;
+                        }
+                        if (!front) {
+                            footsteps.put(footstep, d);
+                        }
+                    }
+                }
+                v1.put(k, x);
+                v_map1.get(d).add(diff_footprint(x, y));
+                if (x == text1_length && y == text2_length) {
+                    // Reached the end in single-path mode.
+                    return diff_path1(v_map1, text1, text2);
+                } else if (done) {
+                    // Front path ran over reverse path.
+                    v_map2 = v_map2.subList(0, footsteps.get(footstep) + 1);
+                    LinkedList<Diff> a = diff_path1(v_map1, text1.substring(0, x),
+                            text2.substring(0, y));
+                    a.addAll(diff_path2(v_map2, text1.substring(x), text2.substring(y)));
+                    return a;
+                }
+            }
+            if (doubleEnd) {
+                // Walk the reverse path one step.
+                v_map2.add(new HashSet<Long>());  // Adds at index 'd'.
+                for (int k = -d; k <= d; k += 2) {
+                    if (k == -d || k != d && v2.get(k - 1) < v2.get(k + 1)) {
+                        x = v2.get(k + 1);
+                    } else {
+                        x = v2.get(k - 1) + 1;
+                    }
+                    y = x - k;
+                    footstep = diff_footprint(text1_length - x, text2_length - y);
+                    if (!front && (footsteps.containsKey(footstep))) {
+                        done = true;
+                    }
+                    if (front) {
+                        footsteps.put(footstep, d);
+                    }
+                    while (!done && x < text1_length && y < text2_length
+                            && text1.charAt(text1_length - x - 1)
+                            == text2.charAt(text2_length - y - 1)) {
+                        x++;
+                        y++;
+                        footstep = diff_footprint(text1_length - x, text2_length - y);
+                        if (!front && (footsteps.containsKey(footstep))) {
+                            done = true;
+                        }
+                        if (front) {
+                            footsteps.put(footstep, d);
+                        }
+                    }
+                    v2.put(k, x);
+                    v_map2.get(d).add(diff_footprint(x, y));
+                    if (done) {
+                        // Reverse path ran over front path.
+                        v_map1 = v_map1.subList(0, footsteps.get(footstep) + 1);
+                        LinkedList<Diff> a
+                                = diff_path1(v_map1, text1.substring(0, text1_length - x),
+                                text2.substring(0, text2_length - y));
+                        a.addAll(diff_path2(v_map2, text1.substring(text1_length - x),
+                                text2.substring(text2_length - y)));
+                        return a;
+                    }
+                }
+            }
+        }
+        // Number of diffs equals number of characters, no commonality at all.
+        return null;
+    }
+    /**
+     * Work from the middle back to the start to determine the path.
+     * @param v_map List of path sets.
+     * @param text1 Old string fragment to be diffed.
+     * @param text2 New string fragment to be diffed.
+     * @return LinkedList of Diff objects.
+     */
+    protected LinkedList<Diff> diff_path1(List<Set<Long>> v_map,
+                                          String text1, String text2) {
+        LinkedList<Diff> path = new LinkedList<Diff>();
+        int x = text1.length();
+        int y = text2.length();
+        Operation last_op = null;
+        for (int d = v_map.size() - 2; d >= 0; d--) {
+            while (true) {
+                if (v_map.get(d).contains(diff_footprint(x - 1, y))) {
+                    x--;
+                    if (last_op == Operation.DELETE) {
+                        path.getFirst().text = text1.charAt(x) + path.getFirst().text;
+                    } else {
+                        path.addFirst(new Diff(Operation.DELETE,
+                                text1.substring(x, x + 1)));
+                    }
+                    last_op = Operation.DELETE;
+                    break;
+                } else if (v_map.get(d).contains(diff_footprint(x, y - 1))) {
+                    y--;
+                    if (last_op == Operation.INSERT) {
+                        path.getFirst().text = text2.charAt(y) + path.getFirst().text;
+                    } else {
+                        path.addFirst(new Diff(Operation.INSERT,
+                                text2.substring(y, y + 1)));
+                    }
+                    last_op = Operation.INSERT;
+                    break;
+                } else {
+                    x--;
+                    y--;
+                    assert (text1.charAt(x) == text2.charAt(y))
+                            : "No diagonal.  Can't happen. (diff_path1)";
+                    if (last_op == Operation.EQUAL) {
+                        path.getFirst().text = text1.charAt(x) + path.getFirst().text;
+                    } else {
+                        path.addFirst(new Diff(Operation.EQUAL, text1.substring(x, x + 1)));
+                    }
+                    last_op = Operation.EQUAL;
+                }
+            }
+        }
+        return path;
+    }
+    /**
+     * Work from the middle back to the end to determine the path.
+     * @param v_map List of path sets.
+     * @param text1 Old string fragment to be diffed.
+     * @param text2 New string fragment to be diffed.
+     * @return LinkedList of Diff objects.
+     */
+    protected LinkedList<Diff> diff_path2(List<Set<Long>> v_map,
+                                          String text1, String text2) {
+        LinkedList<Diff> path = new LinkedList<Diff>();
+        int x = text1.length();
+        int y = text2.length();
+        Operation last_op = null;
+        for (int d = v_map.size() - 2; d >= 0; d--) {
+            while (true) {
+                if (v_map.get(d).contains(diff_footprint(x - 1, y))) {
+                    x--;
+                    if (last_op == Operation.DELETE) {
+                        path.getLast().text += text1.charAt(text1.length() - x - 1);
+                    } else {
+                        path.addLast(new Diff(Operation.DELETE,
+                                text1.substring(text1.length() - x - 1, text1.length() - x)));
+                    }
+                    last_op = Operation.DELETE;
+                    break;
+                } else if (v_map.get(d).contains(diff_footprint(x, y - 1))) {
+                    y--;
+                    if (last_op == Operation.INSERT) {
+                        path.getLast().text += text2.charAt(text2.length() - y - 1);
+                    } else {
+                        path.addLast(new Diff(Operation.INSERT,
+                                text2.substring(text2.length() - y - 1, text2.length() - y)));
+                    }
+                    last_op = Operation.INSERT;
+                    break;
+                } else {
+                    x--;
+                    y--;
+                    assert (text1.charAt(text1.length() - x - 1)
+                            == text2.charAt(text2.length() - y - 1))
+                            : "No diagonal.  Can't happen. (diff_path2)";
+                    if (last_op == Operation.EQUAL) {
+                        path.getLast().text += text1.charAt(text1.length() - x - 1);
+                    } else {
+                        path.addLast(new Diff(Operation.EQUAL,
+                                text1.substring(text1.length() - x - 1, text1.length() - x)));
+                    }
+                    last_op = Operation.EQUAL;
+                }
+            }
+        }
+        return path;
+    }
+    /**
+     * Compute a good hash of two integers.
+     * @param x First int.
+     * @param y Second int.
+     * @return A long made up of both ints.
+     */
+    protected long diff_footprint(int x, int y) {
+        // The maximum size for a long is 9,223,372,036,854,775,807
+        // The maximum size for an int is 2,147,483,647
+        // Two ints fit nicely in one long.
+        long result = x;
+        result = result << 32;
+        result += y;
+        return result;
+    }
+    /**
+     * Determine the common prefix of two strings
+     * @param text1 First string.
+     * @param text2 Second string.
+     * @return The number of characters common to the start of each string.
+     */
+    public int diff_commonPrefix(String text1, String text2) {
+        // Performance analysis: http://neil.fraser.name/news/2007/10/09/
+        int n = Math.min(text1.length(), text2.length());
+        for (int i = 0; i < n; i++) {
+            if (text1.charAt(i) != text2.charAt(i)) {
+                return i;
+            }
+        }
+        return n;
+    }
+    /**
+     * Determine the common suffix of two strings
+     * @param text1 First string.
+     * @param text2 Second string.
+     * @return The number of characters common to the end of each string.
+     */
+    public int diff_commonSuffix(String text1, String text2) {
+        // Performance analysis: http://neil.fraser.name/news/2007/10/09/
+        int text1_length = text1.length();
+        int text2_length = text2.length();
+        int n = Math.min(text1_length, text2_length);
+        for (int i = 1; i <= n; i++) {
+            if (text1.charAt(text1_length - i) != text2.charAt(text2_length - i)) {
+                return i - 1;
+            }
+        }
+        return n;
+    }
+    /**
+     * Do the two texts share a substring which is at least half the length of
+     * the longer text?
+     * @param text1 First string.
+     * @param text2 Second string.
+     * @return Five element String array, containing the prefix of text1, the
+     *     suffix of text1, the prefix of text2, the suffix of text2 and the
+     *     common middle.  Or null if there was no match.
+     */
+    protected String[] diff_halfMatch(String text1, String text2) {
+        String longtext = text1.length() > text2.length() ? text1 : text2;
+        String shorttext = text1.length() > text2.length() ? text2 : text1;
+        if (longtext.length() < 10 || shorttext.length() < 1) {
+            return null;  // Pointless.
+        }
+
+        // First check if the second quarter is the seed for a half-match.
+        String[] hm1 = diff_halfMatchI(longtext, shorttext,
+                (longtext.length() + 3) / 4);
+        // Check again based on the third quarter.
+        String[] hm2 = diff_halfMatchI(longtext, shorttext,
+                (longtext.length() + 1) / 2);
+        String[] hm;
+        if (hm1 == null && hm2 == null) {
+            return null;
+        } else if (hm2 == null) {
+            hm = hm1;
+        } else if (hm1 == null) {
+            hm = hm2;
+        } else {
+            // Both matched.  Select the longest.
+            hm = hm1[4].length() > hm2[4].length() ? hm1 : hm2;
+        }
+        // A half-match was found, sort out the return data.
+        if (text1.length() > text2.length()) {
+            return hm;
+            //return new String[]{hm[0], hm[1], hm[2], hm[3], hm[4]};
+        } else {
+            return new String[]{hm[2], hm[3], hm[0], hm[1], hm[4]};
+        }
+    }
+    /**
+     * Does a substring of shorttext exist within longtext such that the
+     * substring is at least half the length of longtext?
+     * @param longtext Longer string.
+     * @param shorttext Shorter string.
+     * @param i Start index of quarter length substring within longtext.
+     * @return Five element String array, containing the prefix of longtext, the
+     *     suffix of longtext, the prefix of shorttext, the suffix of shorttext
+     *     and the common middle.  Or null if there was no match.
+     */
+    private String[] diff_halfMatchI(String longtext, String shorttext, int i) {
+        // Start with a 1/4 length substring at position i as a seed.
+        String seed = longtext.substring(i, i + longtext.length() / 4);
+        int j = -1;
+        String best_common = "";
+        String best_longtext_a = "", best_longtext_b = "";
+        String best_shorttext_a = "", best_shorttext_b = "";
+        while ((j = shorttext.indexOf(seed, j + 1)) != -1) {
+            int prefixLength = diff_commonPrefix(longtext.substring(i),  shorttext.substring(j));
+            int suffixLength = diff_commonSuffix(longtext.substring(0, i),
+                    shorttext.substring(0, j));
+            if (best_common.length() < suffixLength + prefixLength) {
+                best_common = shorttext.substring(j - suffixLength, j)
+                        + shorttext.substring(j, j + prefixLength);
+                best_longtext_a = longtext.substring(0, i - suffixLength);
+                best_longtext_b = longtext.substring(i + prefixLength);
+                best_shorttext_a = shorttext.substring(0, j - suffixLength);
+                best_shorttext_b = shorttext.substring(j + prefixLength);
+            }
+        }
+        if (best_common.length() >= longtext.length() / 2) {
+            return new String[]{best_longtext_a, best_longtext_b,
+                    best_shorttext_a, best_shorttext_b, best_common};
+        } else {
+            return null;
+        }
+    }
+    /**
+     * Reduce the number of edits by eliminating semantically trivial equalities.
+     * @param diffs LinkedList of Diff objects.
+     */
+    public void diff_cleanupSemantic(LinkedList<Diff> diffs) {
+        if (diffs.isEmpty()) {
+            return;
+        }
+        boolean changes = false;
+        Stack<Diff> equalities = new Stack<Diff>();  // Stack of qualities.
+        String lastequality = null; // Always equal to equalities.lastElement().text
+        ListIterator<Diff> pointer = diffs.listIterator();
+        // Number of characters that changed prior to the equality.
+        int length_changes1 = 0;
+        // Number of characters that changed after the equality.
+        int length_changes2 = 0;
+        Diff thisDiff = pointer.next();
+        while (thisDiff != null) {
+            if (thisDiff.operation == Operation.EQUAL) {
+                // equality found
+                equalities.push(thisDiff);
+                length_changes1 = length_changes2;
+                length_changes2 = 0;
+                lastequality = thisDiff.text;
+            } else {
+                // an insertion or deletion
+                length_changes2 += thisDiff.text.length();
+                if (lastequality != null && (lastequality.length() <= length_changes1)
+                        && (lastequality.length() <= length_changes2)) {
+                    //System.out.println("Splitting: '" + lastequality + "'");
+                    // Walk back to offending equality.
+                    while (thisDiff != equalities.lastElement()) {
+                        thisDiff = pointer.previous();
+                    }
+                    pointer.next();
+                    // Replace equality with a delete.
+                    pointer.set(new Diff(Operation.DELETE, lastequality));
+                    // Insert a corresponding an insert.
+                    pointer.add(new Diff(Operation.INSERT, lastequality));
+
+                    equalities.pop();  // Throw away the equality we just deleted.
+                    if (!equalities.empty()) {
+                        // Throw away the previous equality (it needs to be reevaluated).
+                        equalities.pop();
+                    }
+                    if (equalities.empty()) {
+                        // There are no previous equalities, walk back to the start.
+                        while (pointer.hasPrevious()) {
+                            pointer.previous();
+                        }
+                    } else {
+                        // There is a safe equality we can fall back to.
+                        thisDiff = equalities.lastElement();
+                        while (thisDiff != pointer.previous()) {
+                            // Intentionally empty loop.
+                        }
+                    }
+                    length_changes1 = 0;  // Reset the counters.
+                    length_changes2 = 0;
+                    lastequality = null;
+                    changes = true;
+                }
+            }
+            thisDiff = pointer.hasNext() ? pointer.next() : null;
+        }
+        if (changes) {
+            diff_cleanupMerge(diffs);
+        }
+        diff_cleanupSemanticLossless(diffs);
+    }
+    /**
+     * Look for single edits surrounded on both sides by equalities
+     * which can be shifted sideways to align the edit to a word boundary.
+     * e.g: The c<ins>at c</ins>ame. -> The <ins>cat </ins>came.
+     * @param diffs LinkedList of Diff objects.
+     */
+    public void diff_cleanupSemanticLossless(LinkedList<Diff> diffs) {
+        String equality1, edit, equality2;
+        String commonString;
+        int commonOffset;
+        int score, bestScore;
+        String bestEquality1, bestEdit, bestEquality2;
+        // Create a new iterator at the start.
+        ListIterator<Diff> pointer = diffs.listIterator();
+        Diff prevDiff = pointer.hasNext() ? pointer.next() : null;
+        Diff thisDiff = pointer.hasNext() ? pointer.next() : null;
+        Diff nextDiff = pointer.hasNext() ? pointer.next() : null;
+        // Intentionally ignore the first and last element (don't need checking).
+        while (nextDiff != null) {
+            if (prevDiff.operation == Operation.EQUAL &&
+                    nextDiff.operation == Operation.EQUAL) {
+                // This is a single edit surrounded by equalities.
+                equality1 = prevDiff.text;
+                edit = thisDiff.text;
+                equality2 = nextDiff.text;
+
+                // First, shift the edit as far left as possible.
+                commonOffset = diff_commonSuffix(equality1, edit);
+                if (commonOffset != 0) {
+                    commonString = edit.substring(edit.length() - commonOffset);
+                    equality1 = equality1.substring(0, equality1.length() - commonOffset);
+                    edit = commonString + edit.substring(0, edit.length() - commonOffset);
+                    equality2 = commonString + equality2;
+                }
+                // Second, step character by character right, looking for the best fit.
+                bestEquality1 = equality1;
+                bestEdit = edit;
+                bestEquality2 = equality2;
+                bestScore = diff_cleanupSemanticScore(equality1, edit)
+                        + diff_cleanupSemanticScore(edit, equality2);
+                while (edit.length() != 0 && equality2.length() != 0
+                        && edit.charAt(0) == equality2.charAt(0)) {
+                    equality1 += edit.charAt(0);
+                    edit = edit.substring(1) + equality2.charAt(0);
+                    equality2 = equality2.substring(1);
+                    score = diff_cleanupSemanticScore(equality1, edit)
+                            + diff_cleanupSemanticScore(edit, equality2);
+                    // The >= encourages trailing rather than leading whitespace on edits.
+                    if (score >= bestScore) {
+                        bestScore = score;
+                        bestEquality1 = equality1;
+                        bestEdit = edit;
+                        bestEquality2 = equality2;
+                    }
+                }
+
+                if (!prevDiff.text.equals(bestEquality1)) {
+                    // We have an improvement, save it back to the diff.
+                    if (bestEquality1.length() != 0) {
+                        prevDiff.text = bestEquality1;
+                    } else {
+                        pointer.previous(); // Walk past nextDiff.
+                        pointer.previous(); // Walk past thisDiff.
+                        pointer.previous(); // Walk past prevDiff.
+                        pointer.remove(); // Delete prevDiff.
+                        pointer.next(); // Walk past thisDiff.
+                        pointer.next(); // Walk past nextDiff.
+                    }
+                    thisDiff.text = bestEdit;
+                    if (bestEquality2.length() != 0) {
+                        nextDiff.text = bestEquality2;
+                    } else {
+                        pointer.remove(); // Delete nextDiff.
+                        nextDiff = thisDiff;
+                        thisDiff = prevDiff;
+                    }
+                }
+            }
+            prevDiff = thisDiff;
+            thisDiff = nextDiff;
+            nextDiff = pointer.hasNext() ? pointer.next() : null;
+        }
+    }
+    /**
+     * Given two strings, compute a score representing whether the internal
+     * boundary falls on logical boundaries.
+     * Scores range from 5 (best) to 0 (worst).
+     * @param one First string.
+     * @param two Second string.
+     * @return The score.
+     */
+    private int diff_cleanupSemanticScore(String one, String two) {
+        if (one.length() == 0 || two.length() == 0) {
+            // Edges are the best.
+            return 5;
+        }
+        // Each port of this function behaves slightly differently due to
+        // subtle differences in each language's definition of things like
+        // 'whitespace'.  Since this function's purpose is largely cosmetic,
+        // the choice has been made to use each language's native features
+        // rather than force total conformity.
+        int score = 0;
+        // One point for non-alphanumeric.
+        if (!Character.isLetterOrDigit(one.charAt(one.length() - 1))
+                || !Character.isLetterOrDigit(two.charAt(0))) {
+            score++;
+            // Two points for whitespace.
+            if (Character.isWhitespace(one.charAt(one.length() - 1))
+                    || Character.isWhitespace(two.charAt(0))) {
+                score++;
+                // Three points for line breaks.
+                if (Character.getType(one.charAt(one.length() - 1)) == Character.CONTROL
+                        || Character.getType(two.charAt(0)) == Character.CONTROL) {
+                    score++;
+                    // Four points for blank lines.
+                    if (BLANKLINEEND.matcher(one).find()
+                            || BLANKLINESTART.matcher(two).find()) {
+                        score++;
+                    }
+                }
+            }
+        }
+        return score;
+    }
+    private Pattern BLANKLINEEND
+            = Pattern.compile("\\n\\r?\\n\\Z", Pattern.DOTALL);
+    private Pattern BLANKLINESTART
+            = Pattern.compile("\\A\\r?\\n\\r?\\n", Pattern.DOTALL);
+    /**
+     * Reduce the number of edits by eliminating operationally trivial equalities.
+     * @param diffs LinkedList of Diff objects.
+     */
+    public void diff_cleanupEfficiency(LinkedList<Diff> diffs) {
+        if (diffs.isEmpty()) {
+            return;
+        }
+        boolean changes = false;
+        Stack<Diff> equalities = new Stack<Diff>();  // Stack of equalities.
+        String lastequality = null; // Always equal to equalities.lastElement().text
+        ListIterator<Diff> pointer = diffs.listIterator();
+        // Is there an insertion operation before the last equality.
+        boolean pre_ins = false;
+        // Is there a deletion operation before the last equality.
+        boolean pre_del = false;
+        // Is there an insertion operation after the last equality.
+        boolean post_ins = false;
+        // Is there a deletion operation after the last equality.
+        boolean post_del = false;
+        Diff thisDiff = pointer.next();
+        Diff safeDiff = thisDiff;  // The last Diff that is known to be unsplitable.
+        while (thisDiff != null) {
+            if (thisDiff.operation == Operation.EQUAL) {
+                // equality found
+                if (thisDiff.text.length() < Diff_EditCost && (post_ins || post_del)) {
+                    // Candidate found.
+                    equalities.push(thisDiff);
+                    pre_ins = post_ins;
+                    pre_del = post_del;
+                    lastequality = thisDiff.text;
+                } else {
+                    // Not a candidate, and can never become one.
+                    equalities.clear();
+                    lastequality = null;
+                    safeDiff = thisDiff;
+                }
+                post_ins = post_del = false;
+            } else {
+                // an insertion or deletion
+                if (thisDiff.operation == Operation.DELETE) {
+                    post_del = true;
+                } else {
+                    post_ins = true;
+                }
+                /*
+                 * Five types to be split:
+                 * <ins>A</ins><del>B</del>XY<ins>C</ins><del>D</del>
+                 * <ins>A</ins>X<ins>C</ins><del>D</del>
+                 * <ins>A</ins><del>B</del>X<ins>C</ins>
+                 * <ins>A</del>X<ins>C</ins><del>D</del>
+                 * <ins>A</ins><del>B</del>X<del>C</del>
+                 */
+                if (lastequality != null
+                        && ((pre_ins && pre_del && post_ins && post_del)
+                        || ((lastequality.length() < Diff_EditCost / 2)
+                        && ((pre_ins ? 1 : 0) + (pre_del ? 1 : 0)
+                        + (post_ins ? 1 : 0) + (post_del ? 1 : 0)) == 3))) {
+                    //System.out.println("Splitting: '" + lastequality + "'");
+                    // Walk back to offending equality.
+                    while (thisDiff != equalities.lastElement()) {
+                        thisDiff = pointer.previous();
+                    }
+                    pointer.next();
+
+                    // Replace equality with a delete.
+                    pointer.set(new Diff(Operation.DELETE, lastequality));
+                    // Insert a corresponding an insert.
+                    pointer.add(thisDiff = new Diff(Operation.INSERT, lastequality));
+
+                    equalities.pop();  // Throw away the equality we just deleted.
+                    lastequality = null;
+                    if (pre_ins && pre_del) {
+                        // No changes made which could affect previous entry, keep going.
+                        post_ins = post_del = true;
+                        equalities.clear();
+                        safeDiff = thisDiff;
+                    } else {
+                        if (!equalities.empty()) {
+                            // Throw away the previous equality (it needs to be reevaluated).
+                            equalities.pop();
+                        }
+                        if (equalities.empty()) {
+                            // There are no previous questionable equalities,
+                            // walk back to the last known safe diff.
+                            thisDiff = safeDiff;
+                        } else {
+                            // There is an equality we can fall back to.
+                            thisDiff = equalities.lastElement();
+                        }
+                        while (thisDiff != pointer.previous()) {
+                            // Intentionally empty loop.
+                        }
+                        post_ins = post_del = false;
+                    }
+                    changes = true;
+                }
+            }
+            thisDiff = pointer.hasNext() ? pointer.next() : null;
+        }
+        if (changes) {
+            diff_cleanupMerge(diffs);
+        }
+    }
+    /**
+     * Reorder and merge like edit sections.  Merge equalities.
+     * Any edit section can move as long as it doesn't cross an equality.
+     * @param diffs LinkedList of Diff objects.
+     */
+    public void diff_cleanupMerge(LinkedList<Diff> diffs) {
+        diffs.add(new Diff(Operation.EQUAL, ""));  // Add a dummy entry at the end.
+        ListIterator<Diff> pointer = diffs.listIterator();
+        int count_delete = 0;
+        int count_insert = 0;
+        String text_delete = "";
+        String text_insert = "";
+        Diff thisDiff = pointer.next();
+        Diff prevEqual = null;
+        int commonlength;
+        while (thisDiff != null) {
+            switch (thisDiff.operation) {
+                case INSERT:
+                    count_insert++;
+                    text_insert += thisDiff.text;
+                    prevEqual = null;
+                    break;
+                case DELETE:
+                    count_delete++;
+                    text_delete += thisDiff.text;
+                    prevEqual = null;
+                    break;
+                case EQUAL:
+                    if (count_delete != 0 || count_insert != 0) {
+                        // Delete the offending records.
+                        pointer.previous();  // Reverse direction.
+                        while (count_delete-- > 0) {
+                            pointer.previous();
+                            pointer.remove();
+                        }
+                        while (count_insert-- > 0) {
+                            pointer.previous();
+                            pointer.remove();
+                        }
+                        if (count_delete != 0 && count_insert != 0) {
+                            // Factor out any common prefixies.
+                            commonlength = diff_commonPrefix(text_insert, text_delete);
+                            if (commonlength != 0) {
+                                if (pointer.hasPrevious()) {
+                                    thisDiff = pointer.previous();
+                                    assert thisDiff.operation == Operation.EQUAL
+                                            : "Previous diff should have been an equality.";
+                                    thisDiff.text += text_insert.substring(0, commonlength);
+                                    pointer.next();
+                                } else {
+                                    pointer.add(new Diff(Operation.EQUAL,
+                                            text_insert.substring(0, commonlength)));
+                                }
+                                text_insert = text_insert.substring(commonlength);
+                                text_delete = text_delete.substring(commonlength);
+                            }
+                            // Factor out any common suffixies.
+                            commonlength = diff_commonSuffix(text_insert, text_delete);
+                            if (commonlength != 0) {
+                                thisDiff = pointer.next();
+                                thisDiff.text = text_insert.substring(text_insert.length()
+                                        - commonlength) + thisDiff.text;
+                                text_insert = text_insert.substring(0, text_insert.length()
+                                        - commonlength);
+                                text_delete = text_delete.substring(0, text_delete.length()
+                                        - commonlength);
+                                pointer.previous();
+                            }
+                        }
+                        // Insert the merged records.
+                        if (text_delete.length() != 0) {
+                            pointer.add(new Diff(Operation.DELETE, text_delete));
+                        }
+                        if (text_insert.length() != 0) {
+                            pointer.add(new Diff(Operation.INSERT, text_insert));
+                        }
+                        // Step forward to the equality.
+                        thisDiff = pointer.hasNext() ? pointer.next() : null;
+                    } else if (prevEqual != null) {
+                        // Merge this equality with the previous one.
+                        prevEqual.text += thisDiff.text;
+                        pointer.remove();
+                        thisDiff = pointer.previous();
+                        pointer.next();  // Forward direction
+                    }
+                    count_insert = 0;
+                    count_delete = 0;
+                    text_delete = "";
+                    text_insert = "";
+                    prevEqual = thisDiff;
+                    break;
+            }
+            thisDiff = pointer.hasNext() ? pointer.next() : null;
+        }
+        // System.out.println(diff);
+        if (diffs.getLast().text.length() == 0) {
+            diffs.removeLast();  // Remove the dummy entry at the end.
+        }
+        /*
+         * Second pass: look for single edits surrounded on both sides by equalities
+         * which can be shifted sideways to eliminate an equality.
+         * e.g: A<ins>BA</ins>C -> <ins>AB</ins>AC
+         */
+        boolean changes = false;
+        // Create a new iterator at the start.
+        // (As opposed to walking the current one back.)
+        pointer = diffs.listIterator();
+        Diff prevDiff = pointer.hasNext() ? pointer.next() : null;
+        thisDiff = pointer.hasNext() ? pointer.next() : null;
+        Diff nextDiff = pointer.hasNext() ? pointer.next() : null;
+        // Intentionally ignore the first and last element (don't need checking).
+        while (nextDiff != null) {
+            if (prevDiff.operation == Operation.EQUAL &&
+                    nextDiff.operation == Operation.EQUAL) {
+                // This is a single edit surrounded by equalities.
+                if (thisDiff.text.endsWith(prevDiff.text)) {
+                    // Shift the edit over the previous equality.
+                    thisDiff.text = prevDiff.text + thisDiff.text.substring(0, thisDiff.text.length() - prevDiff.text.length());
+                    nextDiff.text = prevDiff.text + nextDiff.text;
+                    pointer.previous(); // Walk past nextDiff.
+                    pointer.previous(); // Walk past thisDiff.
+                    pointer.previous(); // Walk past prevDiff.
+                    pointer.remove(); // Delete prevDiff.
+                    pointer.next(); // Walk past thisDiff.
+                    thisDiff = pointer.next(); // Walk past nextDiff.
+                    nextDiff = pointer.hasNext() ? pointer.next() : null;
+                    changes = true;
+                } else if (thisDiff.text.startsWith(nextDiff.text)) {
+                    // Shift the edit over the next equality.
+                    prevDiff.text += nextDiff.text;
+                    thisDiff.text = thisDiff.text.substring(nextDiff.text.length())
+                            + nextDiff.text;
+                    pointer.remove(); // Delete nextDiff.
+                    nextDiff = pointer.hasNext() ? pointer.next() : null;
+                    changes = true;
+                }
+            }
+            prevDiff = thisDiff;
+            thisDiff = nextDiff;
+            nextDiff = pointer.hasNext() ? pointer.next() : null;
+        }
+        // If shifts were made, the diff needs reordering and another shift sweep.
+        if (changes) {
+            diff_cleanupMerge(diffs);
+        }
+    }
+    /**
+     * loc is a location in text1, compute and return the equivalent location in
+     * text2.
+     * e.g. "The cat" vs "The big cat", 1->1, 5->8
+     * @param diffs LinkedList of Diff objects.
+     * @param loc Location within text1.
+     * @return Location within text2.
+     */
+    public int diff_xIndex(LinkedList<Diff> diffs, int loc) {
+        int chars1 = 0;
+        int chars2 = 0;
+        int last_chars1 = 0;
+        int last_chars2 = 0;
+        Diff lastDiff = null;
+        for (Diff aDiff : diffs) {
+            if (aDiff.operation != Operation.INSERT) {
+                // Equality or deletion.
+                chars1 += aDiff.text.length();
+            }
+            if (aDiff.operation != Operation.DELETE) {
+                // Equality or insertion.
+                chars2 += aDiff.text.length();
+            }
+            if (chars1 > loc) {
+                // Overshot the location.
+                lastDiff = aDiff;
+                break;
+            }
+            last_chars1 = chars1;
+            last_chars2 = chars2;
+        }
+        if (lastDiff != null && lastDiff.operation == Operation.DELETE) {
+            // The location was deleted.
+            return last_chars2;
+        }
+        // Add the remaining character length.
+        return last_chars2 + (loc - last_chars1);
+    }
+    /**
+     * Convert a Diff list into a pretty HTML report.
+     * @param diffs LinkedList of Diff objects.
+     * @return HTML representation.
+     */
+    public String diff_prettyHtml(LinkedList<Diff> diffs) {
+        StringBuilder html = new StringBuilder();
+        int i = 0;
+        for (Diff aDiff : diffs) {
+            String text = aDiff.text.replace("&", "&amp;").replace("<", "&lt;")
+                    .replace(">", "&gt;").replace("\n", "&para;<BR>");
+            switch (aDiff.operation) {
+                case INSERT:
+                    html.append("<INS STYLE=\"background:green;\" TITLE=\"i=").append(i)
+                            .append("\">").append(text).append("</INS>");
+                    break;
+                case DELETE:
+                    html.append("<DEL STYLE=\"background:red;\" TITLE=\"i=").append(i)
+                            .append("\">").append(text).append("</DEL>");
+                    break;
+                case EQUAL:
+                    html.append("<SPAN TITLE=\"i=").append(i).append("\">").append(text)
+                            .append("</SPAN>");
+                    break;
+            }
+            if (aDiff.operation != Operation.DELETE) {
+                i += aDiff.text.length();
+            }
+        }
+        return html.toString();
+    }
+    /**
+     * Compute and return the source text (all equalities and deletions).
+     * @param diffs LinkedList of Diff objects.
+     * @return Source text.
+     */
+    public String diff_text1(LinkedList<Diff> diffs) {
+        StringBuilder text = new StringBuilder();
+        for (Diff aDiff : diffs) {
+            if (aDiff.operation != Operation.INSERT) {
+                text.append(aDiff.text);
+            }
+        }
+        return text.toString();
+    }
+    /**
+     * Compute and return the destination text (all equalities and insertions).
+     * @param diffs LinkedList of Diff objects.
+     * @return Destination text.
+     */
+    public String diff_text2(LinkedList<Diff> diffs) {
+        StringBuilder text = new StringBuilder();
+        for (Diff aDiff : diffs) {
+            if (aDiff.operation != Operation.DELETE) {
+                text.append(aDiff.text);
+            }
+        }
+        return text.toString();
+    }
+    /**
+     * Compute the Levenshtein distance; the number of inserted, deleted or
+     * substituted characters.
+     * @param diffs LinkedList of Diff objects.
+     * @return Number of changes.
+     */
+    public int diff_levenshtein(LinkedList<Diff> diffs) {
+        int levenshtein = 0;
+        int insertions = 0;
+        int deletions = 0;
+        for (Diff aDiff : diffs) {
+            switch (aDiff.operation) {
+                case INSERT:
+                    insertions += aDiff.text.length();
+                    break;
+                case DELETE:
+                    deletions += aDiff.text.length();
+                    break;
+                case EQUAL:
+                    // A deletion and an insertion is one substitution.
+                    levenshtein += Math.max(insertions, deletions);
+                    insertions = 0;
+                    deletions = 0;
+                    break;
+            }
+        }
+        levenshtein += Math.max(insertions, deletions);
+        return levenshtein;
+    }
+    /**
+     * Crush the diff into an encoded string which describes the operations
+     * required to transform text1 into text2.
+     * E.g. =3\t-2\t+ing  -> Keep 3 chars, delete 2 chars, insert 'ing'.
+     * Operations are tab-separated.  Inserted text is escaped using %xx notation.
+     * @param diffs Array of diff tuples.
+     * @return Delta text.
+     */
+    public String diff_toDelta(LinkedList<Diff> diffs) {
+        StringBuilder text = new StringBuilder();
+        for (Diff aDiff : diffs) {
+            switch (aDiff.operation) {
+                case INSERT:
+                    try {
+                        text.append("+").append(URLEncoder.encode(aDiff.text, "UTF-8")
+                                .replace('+', ' ')).append("\t");
+                    } catch (UnsupportedEncodingException e) {
+                        // Not likely on modern system.
+                        throw new Error("This system does not support UTF-8.", e);
+                    }
+                    break;
+                case DELETE:
+                    text.append("-").append(aDiff.text.length()).append("\t");
+                    break;
+                case EQUAL:
+                    text.append("=").append(aDiff.text.length()).append("\t");
+                    break;
+            }
+        }
+        String delta = text.toString();
+        if (delta.length() != 0) {
+            // Strip off trailing tab character.
+            delta = delta.substring(0, delta.length() - 1);
+            delta = unescapeForEncodeUriCompatability(delta);
+        }
+        return delta;
+    }
+    /**
+     * Given the original text1, and an encoded string which describes the
+     * operations required to transform text1 into text2, compute the full diff.
+     * @param text1 Source string for the diff.
+     * @param delta Delta text.
+     * @return Array of diff tuples or null if invalid.
+     * @throws IllegalArgumentException If invalid input.
+     */
+    public LinkedList<Diff> diff_fromDelta(String text1, String delta)
+            throws IllegalArgumentException {
+        LinkedList<Diff> diffs = new LinkedList<Diff>();
+        int pointer = 0;  // Cursor in text1
+        String[] tokens = delta.split("\t");
+        for (String token : tokens) {
+            if (token.length() == 0) {
+                // Blank tokens are ok (from a trailing \t).
+                continue;
+            }
+            // Each token begins with a one character parameter which specifies the
+            // operation of this token (delete, insert, equality).
+            String param = token.substring(1);
+            switch (token.charAt(0)) {
+                case '+':
+                    // decode would change all "+" to " "
+                    param = param.replace("+", "%2B");
+                    try {
+                        param = URLDecoder.decode(param, "UTF-8");
+                    } catch (UnsupportedEncodingException e) {
+                        // Not likely on modern system.
+                        throw new Error("This system does not support UTF-8.", e);
+                    } catch (IllegalArgumentException e) {
+                        // Malformed URI sequence.
+                        throw new IllegalArgumentException(
+                                "Illegal escape in diff_fromDelta: " + param, e);
+                    }
+                    diffs.add(new Diff(Operation.INSERT, param));
+                    break;
+                case '-':
+                    // Fall through.
+                case '=':
+                    int n;
+                    try {
+                        n = Integer.parseInt(param);
+                    } catch (NumberFormatException e) {
+                        throw new IllegalArgumentException(
+                                "Invalid number in diff_fromDelta: " + param, e);
+                    }
+                    if (n < 0) {
+                        throw new IllegalArgumentException(
+                                "Negative number in diff_fromDelta: " + param);
+                    }
+                    String text;
+                    try {
+                        text = text1.substring(pointer, pointer += n);
+                    } catch (StringIndexOutOfBoundsException e) {
+                        throw new IllegalArgumentException("Delta length (" + pointer
+                                + ") larger than source text length (" + text1.length()
+                                + ").", e);
+                    }
+                    if (token.charAt(0) == '=') {
+                        diffs.add(new Diff(Operation.EQUAL, text));
+                    } else {
+                        diffs.add(new Diff(Operation.DELETE, text));
+                    }
+                    break;
+                default:
+                    // Anything else is an error.
+                    throw new IllegalArgumentException(
+                            "Invalid diff operation in diff_fromDelta: " + token.charAt(0));
+            }
+        }
+        if (pointer != text1.length()) {
+            throw new IllegalArgumentException("Delta length (" + pointer
+                    + ") smaller than source text length (" + text1.length() + ").");
+        }
+        return diffs;
+    }
+    //  MATCH FUNCTIONS
+    /**
+     * Locate the best instance of 'pattern' in 'text' near 'loc'.
+     * Returns -1 if no match found.
+     * @param text The text to search.
+     * @param pattern The pattern to search for.
+     * @param loc The location to search around.
+     * @return Best match index or -1.
+     */
+    public int match_main(String text, String pattern, int loc) {
+        loc = Math.max(0, Math.min(loc, text.length()));
+        if (text.equals(pattern)) {
+            // Shortcut (potentially not guaranteed by the algorithm)
+            return 0;
+        } else if (text.length() == 0) {
+            // Nothing to match.
+            return -1;
+        } else if (loc + pattern.length() <= text.length()
+                && text.substring(loc, loc + pattern.length()).equals(pattern)) {
+            // Perfect match at the perfect spot!  (Includes case of null pattern)
+            return loc;
+        } else {
+            // Do a fuzzy compare.
+            return match_bitap(text, pattern, loc);
+        }
+    }
+    /**
+     * Locate the best instance of 'pattern' in 'text' near 'loc' using the
+     * Bitap algorithm.  Returns -1 if no match found.
+     * @param text The text to search.
+     * @param pattern The pattern to search for.
+     * @param loc The location to search around.
+     * @return Best match index or -1.
+     */
+    protected int match_bitap(String text, String pattern, int loc) {
+        assert (Match_MaxBits == 0 || pattern.length() <= Match_MaxBits)
+                : "Pattern too long for this application.";
+        // Initialise the alphabet.
+        Map<Character, Integer> s = match_alphabet(pattern);
+        // Highest score beyond which we give up.
+        double score_threshold = Match_Threshold;
+        // Is there a nearby exact match? (speedup)
+        int best_loc = text.indexOf(pattern, loc);
+        if (best_loc != -1) {
+            score_threshold = Math.min(match_bitapScore(0, best_loc, loc, pattern),
+                    score_threshold);
+            // What about in the other direction? (speedup)
+            best_loc = text.lastIndexOf(pattern, loc + pattern.length());
+            if (best_loc != -1) {
+                score_threshold = Math.min(match_bitapScore(0, best_loc, loc, pattern),
+                        score_threshold);
+            }
+        }
+        // Initialise the bit arrays.
+        int matchmask = 1 << (pattern.length() - 1);
+        best_loc = -1;
+        int bin_min, bin_mid;
+        int bin_max = pattern.length() + text.length();
+        // Empty initialization added to appease Java compiler.
+        int[] last_rd = new int[0];
+        for (int d = 0; d < pattern.length(); d++) {
+            // Scan for the best match; each iteration allows for one more error.
+            // Run a binary search to determine how far from 'loc' we can stray at
+            // this error level.
+            bin_min = 0;
+            bin_mid = bin_max;
+            while (bin_min < bin_mid) {
+                if (match_bitapScore(d, loc + bin_mid, loc, pattern)
+                        <= score_threshold) {
+                    bin_min = bin_mid;
+                } else {
+                    bin_max = bin_mid;
+                }
+                bin_mid = (bin_max - bin_min) / 2 + bin_min;
+            }
+            // Use the result from this iteration as the maximum for the next.
+            bin_max = bin_mid;
+            int start = Math.max(1, loc - bin_mid + 1);
+            int finish = Math.min(loc + bin_mid, text.length()) + pattern.length();
+            int[] rd = new int[finish + 2];
+            rd[finish + 1] = (1 << d) - 1;
+            for (int j = finish; j >= start; j--) {
+                int charMatch;
+                if (text.length() <= j - 1 || !s.containsKey(text.charAt(j - 1))) {
+                    // Out of range.
+                    charMatch = 0;
+                } else {
+                    charMatch = s.get(text.charAt(j - 1));
+                }
+                if (d == 0) {
+                    // First pass: exact match.
+                    rd[j] = ((rd[j + 1] << 1) | 1) & charMatch;
+                } else {
+                    // Subsequent passes: fuzzy match.
+                    rd[j] = ((rd[j + 1] << 1) | 1) & charMatch
+                            | (((last_rd[j + 1] | last_rd[j]) << 1) | 1) | last_rd[j + 1];
+                }
+                if ((rd[j] & matchmask) != 0) {
+                    double score = match_bitapScore(d, j - 1, loc, pattern);
+                    // This match will almost certainly be better than any existing
+                    // match.  But check anyway.
+                    if (score <= score_threshold) {
+                        // Told you so.
+                        score_threshold = score;
+                        best_loc = j - 1;
+                        if (best_loc > loc) {
+                            // When passing loc, don't exceed our current distance from loc.
+                            start = Math.max(1, 2 * loc - best_loc);
+                        } else {
+                            // Already passed loc, downhill from here on in.
+                            break;
+                        }
+                    }
+                }
+            }
+            if (match_bitapScore(d + 1, loc, loc, pattern) > score_threshold) {
+                // No hope for a (better) match at greater error levels.
+                break;
+            }
+            last_rd = rd;
+        }
+        return best_loc;
+    }
+    /**
+     * Compute and return the score for a match with e errors and x location.
+     * @param e Number of errors in match.
+     * @param x Location of match.
+     * @param loc Expected location of match.
+     * @param pattern Pattern being sought.
+     * @return Overall score for match (0.0 = good, 1.0 = bad).
+     */
+    private double match_bitapScore(int e, int x, int loc, String pattern) {
+        float accuracy = (float) e / pattern.length();
+        int proximity = Math.abs(loc - x);
+        if (Match_Distance == 0) {
+            // Dodge divide by zero error.
+            return proximity == 0 ? accuracy : 1.0;
+        }
+        return accuracy + (proximity / (float) Match_Distance);
+    }
+    /**
+     * Initialise the alphabet for the Bitap algorithm.
+     * @param pattern The text to encode.
+     * @return Hash of character locations.
+     */
+    protected Map<Character, Integer> match_alphabet(String pattern) {
+        Map<Character, Integer> s = new HashMap<Character, Integer>();
+        char[] char_pattern = pattern.toCharArray();
+        for (char c : char_pattern) {
+            s.put(c, 0);
+        }
+        int i = 0;
+        for (char c : char_pattern) {
+            s.put(c, s.get(c) | (1 << (pattern.length() - i - 1)));
+            i++;
+        }
+        return s;
+    }
+    //  PATCH FUNCTIONS
+    /**
+     * Increase the context until it is unique,
+     * but don't let the pattern expand beyond Match_MaxBits.
+     * @param patch The patch to grow.
+     * @param text Source text.
+     */
+    protected void patch_addContext(Patch patch, String text) {
+        if (text.length() == 0) {
+            return;
+        }
+        String pattern = text.substring(patch.start2, patch.start2 + patch.length1);
+        int padding = 0;
+        // Look for the first and last matches of pattern in text.  If two different
+        // matches are found, increase the pattern length.
+        while (text.indexOf(pattern) != text.lastIndexOf(pattern)
+                && pattern.length() < Match_MaxBits - Patch_Margin - Patch_Margin) {
+            padding += Patch_Margin;
+            pattern = text.substring(Math.max(0, patch.start2 - padding),
+                    Math.min(text.length(), patch.start2 + patch.length1 + padding));
+        }
+        // Add one chunk for good luck.
+        padding += Patch_Margin;
+        // Add the prefix.
+        String prefix = text.substring(Math.max(0, patch.start2 - padding),
+                patch.start2);
+        if (prefix.length() != 0) {
+            patch.diffs.addFirst(new Diff(Operation.EQUAL, prefix));
+        }
+        // Add the suffix.
+        String suffix = text.substring(patch.start2 + patch.length1,
+                Math.min(text.length(), patch.start2 + patch.length1 + padding));
+        if (suffix.length() != 0) {
+            patch.diffs.addLast(new Diff(Operation.EQUAL, suffix));
+        }
+        // Roll back the start points.
+        patch.start1 -= prefix.length();
+        patch.start2 -= prefix.length();
+        // Extend the lengths.
+        patch.length1 += prefix.length() + suffix.length();
+        patch.length2 += prefix.length() + suffix.length();
+    }
+    /**
+     * Compute a list of patches to turn text1 into text2.
+     * A set of diffs will be computed.
+     * @param text1 Old text.
+     * @param text2 New text.
+     * @return LinkedList of Patch objects.
+     */
+    public LinkedList<Patch> patch_make(String text1, String text2) {
+        // No diffs provided, compute our own.
+        LinkedList<Diff> diffs = diff_main(text1, text2, true);
+        if (diffs.size() > 2) {
+            diff_cleanupSemantic(diffs);
+            diff_cleanupEfficiency(diffs);
+        }
+        return patch_make(text1, diffs);
+    }
+    /**
+     * Compute a list of patches to turn text1 into text2.
+     * text1 will be derived from the provided diffs.
+     * @param diffs Array of diff tuples for text1 to text2.
+     * @return LinkedList of Patch objects.
+     */
+    public LinkedList<Patch> patch_make(LinkedList<Diff> diffs) {
+        // No origin string provided, compute our own.
+        String text1 = diff_text1(diffs);
+        return patch_make(text1, diffs);
+    }
+    /**
+     * Compute a list of patches to turn text1 into text2.
+     * text2 is ignored, diffs are the delta between text1 and text2.
+     * @param text1 Old text
+     * @param text2 Ignored.
+     * @param diffs Array of diff tuples for text1 to text2.
+     * @return LinkedList of Patch objects.
+     * @deprecated Prefer patch_make(String text1, LinkedList<Diff> diffs).
+     */
+    public LinkedList<Patch> patch_make(String text1, String text2,
+                                        LinkedList<Diff> diffs) {
+        return patch_make(text1, diffs);
+    }
+    /**
+     * Compute a list of patches to turn text1 into text2.
+     * text2 is not provided, diffs are the delta between text1 and text2.
+     * @param text1 Old text.
+     * @param diffs Array of diff tuples for text1 to text2.
+     * @return LinkedList of Patch objects.
+     */
+    public LinkedList<Patch> patch_make(String text1, LinkedList<Diff> diffs) {
+        LinkedList<Patch> patches = new LinkedList<Patch>();
+        if (diffs.isEmpty()) {
+            return patches;  // Get rid of the null case.
+        }
+        Patch patch = new Patch();
+        int char_count1 = 0;  // Number of characters into the text1 string.
+        int char_count2 = 0;  // Number of characters into the text2 string.
+        // Start with text1 (prepatch_text) and apply the diffs until we arrive at
+        // text2 (postpatch_text). We recreate the patches one by one to determine
+        // context info.
+        String prepatch_text = text1;
+        String postpatch_text = text1;
+        for (Diff aDiff : diffs) {
+            if (patch.diffs.isEmpty() && aDiff.operation != Operation.EQUAL) {
+                // A new patch starts here.
+                patch.start1 = char_count1;
+                patch.start2 = char_count2;
+            }
+            switch (aDiff.operation) {
+                case INSERT:
+                    patch.diffs.add(aDiff);
+                    patch.length2 += aDiff.text.length();
+                    postpatch_text = postpatch_text.substring(0, char_count2)
+                            + aDiff.text + postpatch_text.substring(char_count2);
+                    break;
+                case DELETE:
+                    patch.length1 += aDiff.text.length();
+                    patch.diffs.add(aDiff);
+                    postpatch_text = postpatch_text.substring(0, char_count2)
+                            + postpatch_text.substring(char_count2 + aDiff.text.length());
+                    break;
+                case EQUAL:
+                    if (aDiff.text.length() <= 2 * Patch_Margin
+                            && !patch.diffs.isEmpty() && aDiff != diffs.getLast()) {
+                        // Small equality inside a patch.
+                        patch.diffs.add(aDiff);
+                        patch.length1 += aDiff.text.length();
+                        patch.length2 += aDiff.text.length();
+                    }
+                    if (aDiff.text.length() >= 2 * Patch_Margin) {
+                        // Time for a new patch.
+                        if (!patch.diffs.isEmpty()) {
+                            patch_addContext(patch, prepatch_text);
+                            patches.add(patch);
+                            patch = new Patch();
+                            // Unlike Unidiff, our patch lists have a rolling context.
+                            // http://code.google.com/p/google-diff-match-patch/wiki/Unidiff
+                            // Update prepatch text & pos to reflect the application of the
+                            // just completed patch.
+                            prepatch_text = postpatch_text;
+                            char_count1 = char_count2;
+                        }
+                    }
+                    break;
+            }
+            // Update the current character count.
+            if (aDiff.operation != Operation.INSERT) {
+                char_count1 += aDiff.text.length();
+            }
+            if (aDiff.operation != Operation.DELETE) {
+                char_count2 += aDiff.text.length();
+            }
+        }
+        // Pick up the leftover patch if not empty.
+        if (!patch.diffs.isEmpty()) {
+            patch_addContext(patch, prepatch_text);
+            patches.add(patch);
+        }
+        return patches;
+    }
+    /**
+     * Given an array of patches, return another array that is identical.
+     * @param patches Array of patch objects.
+     * @return Array of patch objects.
+     */
+    public LinkedList<Patch> patch_deepCopy(LinkedList<Patch> patches) {
+        LinkedList<Patch> patchesCopy = new LinkedList<Patch>();
+        for (Patch aPatch : patches) {
+            Patch patchCopy = new Patch();
+            for (Diff aDiff : aPatch.diffs) {
+                Diff diffCopy = new Diff(aDiff.operation, aDiff.text);
+                patchCopy.diffs.add(diffCopy);
+            }
+            patchCopy.start1 = aPatch.start1;
+            patchCopy.start2 = aPatch.start2;
+            patchCopy.length1 = aPatch.length1;
+            patchCopy.length2 = aPatch.length2;
+            patchesCopy.add(patchCopy);
+        }
+        return patchesCopy;
+    }
+    /**
+     * Merge a set of patches onto the text.  Return a patched text, as well
+     * as an array of true/false values indicating which patches were applied.
+     * @param patches Array of patch objects
+     * @param text Old text.
+     * @return Two element Object array, containing the new text and an array of
+     *      boolean values.
+     */
+    public Object[] patch_apply(LinkedList<Patch> patches, String text) {
+        if (patches.isEmpty()) {
+            return new Object[]{text, new boolean[0]};
+        }
+        // Deep copy the patches so that no changes are made to originals.
+        patches = patch_deepCopy(patches);
+        String nullPadding = patch_addPadding(patches);
+        text = nullPadding + text + nullPadding;
+        patch_splitMax(patches);
+        int x = 0;
+        // delta keeps track of the offset between the expected and actual location
+        // of the previous patch.  If there are patches expected at positions 10 and
+        // 20, but the first patch was found at 12, delta is 2 and the second patch
+        // has an effective expected position of 22.
+        int delta = 0;
+        boolean[] results = new boolean[patches.size()];
+        for (Patch aPatch : patches) {
+            int expected_loc = aPatch.start2 + delta;
+            String text1 = diff_text1(aPatch.diffs);
+            int start_loc;
+            int end_loc = -1;
+            if (text1.length() > this.Match_MaxBits) {
+                // patch_splitMax will only provide an oversized pattern in the case of
+                // a monster delete.
+                start_loc = match_main(text,
+                        text1.substring(0, this.Match_MaxBits), expected_loc);
+                if (start_loc != -1) {
+                    end_loc = match_main(text,
+                            text1.substring(text1.length() - this.Match_MaxBits),
+                            expected_loc + text1.length() - this.Match_MaxBits);
+                    if (end_loc == -1 || start_loc >= end_loc) {
+                        // Can't find valid trailing context.  Drop this patch.
+                        start_loc = -1;
+                    }
+                }
+            } else {
+                start_loc = match_main(text, text1, expected_loc);
+            }
+            if (start_loc == -1) {
+                // No match found.  :(
+                results[x] = false;
+                // Subtract the delta for this failed patch from subsequent patches.
+                delta -= aPatch.length2 - aPatch.length1;
+            } else {
+                // Found a match.  :)
+                results[x] = true;
+                delta = start_loc - expected_loc;
+                String text2;
+                if (end_loc == -1) {
+                    text2 = text.substring(start_loc,
+                            Math.min(start_loc + text1.length(), text.length()));
+                } else {
+                    text2 = text.substring(start_loc,
+                            Math.min(end_loc + this.Match_MaxBits, text.length()));
+                }
+                if (text1.equals(text2)) {
+                    // Perfect match, just shove the replacement text in.
+                    text = text.substring(0, start_loc) + diff_text2(aPatch.diffs)
+                            + text.substring(start_loc + text1.length());
+                } else {
+                    // Imperfect match.  Run a diff to get a framework of equivalent
+                    // indices.
+                    LinkedList<Diff> diffs = diff_main(text1, text2, false);
+                    if (text1.length() > this.Match_MaxBits
+                            && diff_levenshtein(diffs) / (float) text1.length()
+                            > this.Patch_DeleteThreshold) {
+                        // The end points match, but the content is unacceptably bad.
+                        results[x] = false;
+                    } else {
+                        diff_cleanupSemanticLossless(diffs);
+                        int index1 = 0;
+                        for (Diff aDiff : aPatch.diffs) {
+                            if (aDiff.operation != Operation.EQUAL) {
+                                int index2 = diff_xIndex(diffs, index1);
+                                if (aDiff.operation == Operation.INSERT) {
+                                    // Insertion
+                                    text = text.substring(0, start_loc + index2) + aDiff.text
+                                            + text.substring(start_loc + index2);
+                                } else if (aDiff.operation == Operation.DELETE) {
+                                    // Deletion
+                                    text = text.substring(0, start_loc + index2)
+                                            + text.substring(start_loc + diff_xIndex(diffs,
+                                            index1 + aDiff.text.length()));
+                                }
+                            }
+                            if (aDiff.operation != Operation.DELETE) {
+                                index1 += aDiff.text.length();
+                            }
+                        }
+                    }
+                }
+            }
+            x++;
+        }
+        // Strip the padding off.
+        text = text.substring(nullPadding.length(), text.length()
+                - nullPadding.length());
+        return new Object[]{text, results};
+    }
+    /**
+     * Add some padding on text start and end so that edges can match something.
+     * Intended to be called only from within patch_apply.
+     * @param patches Array of patch objects.
+     * @return The padding string added to each side.
+     */
+    public String patch_addPadding(LinkedList<Patch> patches) {
+        int paddingLength = this.Patch_Margin;
+        String nullPadding = "";
+        for (int x = 1; x <= paddingLength; x++) {
+            nullPadding += String.valueOf((char) x);
+        }
+        // Bump all the patches forward.
+        for (Patch aPatch : patches) {
+            aPatch.start1 += paddingLength;
+            aPatch.start2 += paddingLength;
+        }
+        // Add some padding on start of first diff.
+        Patch patch = patches.getFirst();
+        LinkedList<Diff> diffs = patch.diffs;
+        if (diffs.isEmpty() || diffs.getFirst().operation != Operation.EQUAL) {
+            // Add nullPadding equality.
+            diffs.addFirst(new Diff(Operation.EQUAL, nullPadding));
+            patch.start1 -= paddingLength;  // Should be 0.
+            patch.start2 -= paddingLength;  // Should be 0.
+            patch.length1 += paddingLength;
+            patch.length2 += paddingLength;
+        } else if (paddingLength > diffs.getFirst().text.length()) {
+            // Grow first equality.
+            Diff firstDiff = diffs.getFirst();
+            int extraLength = paddingLength - firstDiff.text.length();
+            firstDiff.text = nullPadding.substring(firstDiff.text.length())
+                    + firstDiff.text;
+            patch.start1 -= extraLength;
+            patch.start2 -= extraLength;
+            patch.length1 += extraLength;
+            patch.length2 += extraLength;
+        }
+        // Add some padding on end of last diff.
+        patch = patches.getLast();
+        diffs = patch.diffs;
+        if (diffs.isEmpty() || diffs.getLast().operation != Operation.EQUAL) {
+            // Add nullPadding equality.
+            diffs.addLast(new Diff(Operation.EQUAL, nullPadding));
+            patch.length1 += paddingLength;
+            patch.length2 += paddingLength;
+        } else if (paddingLength > diffs.getLast().text.length()) {
+            // Grow last equality.
+            Diff lastDiff = diffs.getLast();
+            int extraLength = paddingLength - lastDiff.text.length();
+            lastDiff.text += nullPadding.substring(0, extraLength);
+            patch.length1 += extraLength;
+            patch.length2 += extraLength;
+        }
+        return nullPadding;
+    }
+    /**
+     * Look through the patches and break up any which are longer than the
+     * maximum limit of the match algorithm.
+     * @param patches LinkedList of Patch objects.
+     */
+    public void patch_splitMax(LinkedList<Patch> patches) {
+        int patch_size;
+        String precontext, postcontext;
+        Patch patch;
+        int start1, start2;
+        boolean empty;
+        Operation diff_type;
+        String diff_text;
+        ListIterator<Patch> pointer = patches.listIterator();
+        Patch bigpatch = pointer.hasNext() ? pointer.next() : null;
+        while (bigpatch != null) {
+            if (bigpatch.length1 <= Match_MaxBits) {
+                bigpatch = pointer.hasNext() ? pointer.next() : null;
+                continue;
+            }
+            // Remove the big old patch.
+            pointer.remove();
+            patch_size = Match_MaxBits;
+            start1 = bigpatch.start1;
+            start2 = bigpatch.start2;
+            precontext = "";
+            while (!bigpatch.diffs.isEmpty()) {
+                // Create one of several smaller patches.
+                patch = new Patch();
+                empty = true;
+                patch.start1 = start1 - precontext.length();
+                patch.start2 = start2 - precontext.length();
+                if (precontext.length() != 0) {
+                    patch.length1 = patch.length2 = precontext.length();
+                    patch.diffs.add(new Diff(Operation.EQUAL, precontext));
+                }
+                while (!bigpatch.diffs.isEmpty()
+                        && patch.length1 < patch_size - Patch_Margin) {
+                    diff_type = bigpatch.diffs.getFirst().operation;
+                    diff_text = bigpatch.diffs.getFirst().text;
+                    if (diff_type == Operation.INSERT) {
+                        // Insertions are harmless.
+                        patch.length2 += diff_text.length();
+                        start2 += diff_text.length();
+                        patch.diffs.addLast(bigpatch.diffs.removeFirst());
+                        empty = false;
+                    } else if (diff_type == Operation.DELETE && patch.diffs.size() == 1
+                            && patch.diffs.getFirst().operation == Operation.EQUAL
+                            && diff_text.length() > 2 * patch_size) {
+                        // This is a large deletion.  Let it pass in one chunk.
+                        patch.length1 += diff_text.length();
+                        start1 += diff_text.length();
+                        empty = false;
+                        patch.diffs.add(new Diff(diff_type, diff_text));
+                        bigpatch.diffs.removeFirst();
+                    } else {
+                        // Deletion or equality.  Only take as much as we can stomach.
+                        diff_text = diff_text.substring(0, Math.min(diff_text.length(),
+                                patch_size - patch.length1 - Patch_Margin));
+                        patch.length1 += diff_text.length();
+                        start1 += diff_text.length();
+                        if (diff_type == Operation.EQUAL) {
+                            patch.length2 += diff_text.length();
+                            start2 += diff_text.length();
+                        } else {
+                            empty = false;
+                        }
+                        patch.diffs.add(new Diff(diff_type, diff_text));
+                        if (diff_text.equals(bigpatch.diffs.getFirst().text)) {
+                            bigpatch.diffs.removeFirst();
+                        } else {
+                            bigpatch.diffs.getFirst().text = bigpatch.diffs.getFirst().text
+                                    .substring(diff_text.length());
+                        }
+                    }
+                }
+                // Compute the head context for the next patch.
+                precontext = diff_text2(patch.diffs);
+                precontext = precontext.substring(Math.max(0, precontext.length()
+                        - Patch_Margin));
+                // Append the end context for this patch.
+                if (diff_text1(bigpatch.diffs).length() > Patch_Margin) {
+                    postcontext = diff_text1(bigpatch.diffs).substring(0, Patch_Margin);
+                } else {
+                    postcontext = diff_text1(bigpatch.diffs);
+                }
+                if (postcontext.length() != 0) {
+                    patch.length1 += postcontext.length();
+                    patch.length2 += postcontext.length();
+                    if (!patch.diffs.isEmpty()
+                            && patch.diffs.getLast().operation == Operation.EQUAL) {
+                        patch.diffs.getLast().text += postcontext;
+                    } else {
+                        patch.diffs.add(new Diff(Operation.EQUAL, postcontext));
+                    }
+                }
+                if (!empty) {
+                    pointer.add(patch);
+                }
+            }
+            bigpatch = pointer.hasNext() ? pointer.next() : null;
+        }
+    }
+    /**
+     * Take a list of patches and return a textual representation.
+     * @param patches List of Patch objects.
+     * @return Text representation of patches.
+     */
+    public String patch_toText(List<Patch> patches) {
+        StringBuilder text = new StringBuilder();
+        for (Patch aPatch : patches) {
+            text.append(aPatch);
+        }
+        return text.toString();
+    }
+    /**
+     * Parse a textual representation of patches and return a List of Patch
+     * objects.
+     * @param textline Text representation of patches.
+     * @return List of Patch objects.
+     * @throws IllegalArgumentException If invalid input.
+     */
+    public List<Patch> patch_fromText(String textline)
+            throws IllegalArgumentException {
+        List<Patch> patches = new LinkedList<Patch>();
+        if (textline.length() == 0) {
+            return patches;
+        }
+        List<String> textList = Arrays.asList(textline.split("\n"));
+        LinkedList<String> text = new LinkedList<String>(textList);
+        Patch patch;
+        Pattern patchHeader
+                = Pattern.compile("^@@ -(\\d+),?(\\d*) \\+(\\d+),?(\\d*) @@$");
+        Matcher m;
+        char sign;
+        String line;
+        while (!text.isEmpty()) {
+            m = patchHeader.matcher(text.getFirst());
+            if (!m.matches()) {
+                throw new IllegalArgumentException(
+                        "Invalid patch string: " + text.getFirst());
+            }
+            patch = new Patch();
+            patches.add(patch);
+            patch.start1 = Integer.parseInt(m.group(1));
+            if (m.group(2).length() == 0) {
+                patch.start1--;
+                patch.length1 = 1;
+            } else if (m.group(2).equals("0")) {
+                patch.length1 = 0;
+            } else {
+                patch.start1--;
+                patch.length1 = Integer.parseInt(m.group(2));
+            }
+            patch.start2 = Integer.parseInt(m.group(3));
+            if (m.group(4).length() == 0) {
+                patch.start2--;
+                patch.length2 = 1;
+            } else if (m.group(4).equals("0")) {
+                patch.length2 = 0;
+            } else {
+                patch.start2--;
+                patch.length2 = Integer.parseInt(m.group(4));
+            }
+            text.removeFirst();
+
+            while (!text.isEmpty()) {
+                try {
+                    sign = text.getFirst().charAt(0);
+                } catch (IndexOutOfBoundsException e) {
+                    // Blank line?  Whatever.
+                    text.removeFirst();
+                    continue;
+                }
+                line = text.getFirst().substring(1);
+                line = line.replace("+", "%2B");  // decode would change all "+" to " "
+                try {
+                    line = URLDecoder.decode(line, "UTF-8");
+                } catch (UnsupportedEncodingException e) {
+                    // Not likely on modern system.
+                    throw new Error("This system does not support UTF-8.", e);
+                } catch (IllegalArgumentException e) {
+                    // Malformed URI sequence.
+                    throw new IllegalArgumentException(
+                            "Illegal escape in patch_fromText: " + line, e);
+                }
+                if (sign == '-') {
+                    // Deletion.
+                    patch.diffs.add(new Diff(Operation.DELETE, line));
+                } else if (sign == '+') {
+                    // Insertion.
+                    patch.diffs.add(new Diff(Operation.INSERT, line));
+                } else if (sign == ' ') {
+                    // Minor equality.
+                    patch.diffs.add(new Diff(Operation.EQUAL, line));
+                } else if (sign == '@') {
+                    // Start of next patch.
+                    break;
+                } else {
+                    // WTF?
+                    throw new IllegalArgumentException(
+                            "Invalid patch mode '" + sign + "' in: " + line);
+                }
+                text.removeFirst();
+            }
+        }
+        return patches;
+    }
+
+
+    /**
+     * Class representing one diff operation.
+     */
+    public static class Diff {
+        /**
+         * One of: INSERT, DELETE or EQUAL.
+         */
+        public Operation operation;
+        /**
+         * The text associated with this diff operation.
+         */
+        public String text;
+
+        /**
+         * Constructor.  Initializes the diff with the provided values.
+         * @param operation One of INSERT, DELETE or EQUAL.
+         * @param text The text being applied.
+         */
+        public Diff(Operation operation, String text) {
+            // Construct a diff with the specified operation and text.
+            this.operation = operation;
+            this.text = text;
+        }
+
+
+        /**
+         * Display a human-readable version of this Diff.
+         * @return text version.
+         */
+        public String toString() {
+            String prettyText = this.text.replace('\n', '\u00b6');
+            return "Diff(" + this.operation + ",\"" + prettyText + "\")";
+        }
+
+
+        /**
+         * Is this Diff equivalent to another Diff?
+         * @param d Another Diff to compare against.
+         * @return true or false.
+         */
+        public boolean equals(Object d) {
+            try {
+                return (((Diff) d).operation == this.operation)
+                        && (((Diff) d).text.equals(this.text));
+            } catch (ClassCastException e) {
+                return false;
+            }
+        }
+    }
+
+
+    /**
+     * Class representing one patch operation.
+     */
+    public static class Patch {
+        public LinkedList<Diff> diffs;
+        public int start1;
+        public int start2;
+        public int length1;
+        public int length2;
+
+
+        /**
+         * Constructor.  Initializes with an empty list of diffs.
+         */
+        public Patch() {
+            this.diffs = new LinkedList<Diff>();
+        }
+
+
+        /**
+         * Emmulate GNU diff's format.
+         * Header: @@ -382,8 +481,9 @@
+         * Indicies are printed as 1-based, not 0-based.
+         * @return The GNU diff string.
+         */
+        public String toString() {
+            String coords1, coords2;
+            if (this.length1 == 0) {
+                coords1 = this.start1 + ",0";
+            } else if (this.length1 == 1) {
+                coords1 = Integer.toString(this.start1 + 1);
+            } else {
+                coords1 = (this.start1 + 1) + "," + this.length1;
+            }
+            if (this.length2 == 0) {
+                coords2 = this.start2 + ",0";
+            } else if (this.length2 == 1) {
+                coords2 = Integer.toString(this.start2 + 1);
+            } else {
+                coords2 = (this.start2 + 1) + "," + this.length2;
+            }
+            StringBuilder text = new StringBuilder();
+            text.append("@@ -").append(coords1).append(" +").append(coords2)
+                    .append(" @@\n");
+            // Escape the body of the patch with %xx notation.
+            for (Diff aDiff : this.diffs) {
+                switch (aDiff.operation) {
+                    case INSERT:
+                        text.append('+');
+                        break;
+                    case DELETE:
+                        text.append('-');
+                        break;
+                    case EQUAL:
+                        text.append(' ');
+                        break;
+                }
+                try {
+                    text.append(URLEncoder.encode(aDiff.text, "UTF-8").replace('+', ' '))
+                            .append("\n");
+                } catch (UnsupportedEncodingException e) {
+                    // Not likely on modern system.
+                    throw new Error("This system does not support UTF-8.", e);
+                }
+            }
+            return unescapeForEncodeUriCompatability(text.toString());
+        }
+    }
+
+
+    /**
+     * Unescape selected chars for compatability with JavaScript's encodeURI.
+     * In speed critical applications this could be dropped since the
+     * receiving application will certainly decode these fine.
+     * Note that this function is case-sensitive.  Thus "%3f" would not be
+     * unescaped.  But this is ok because it is only called with the output of
+     * URLEncoder.encode which returns uppercase hex.
+     *
+     * Example: "%3F" -> "?", "%24" -> "$", etc.
+     *
+     * @param str The string to escape.
+     * @return The escaped string.
+     */
+    private static String unescapeForEncodeUriCompatability(String str) {
+        return str.replace("%21", "!").replace("%7E", "~")
+                .replace("%27", "'").replace("%28", "(").replace("%29", ")")
+                .replace("%3B", ";").replace("%2F", "/").replace("%3F", "?")
+                .replace("%3A", ":").replace("%40", "@").replace("%26", "&")
+                .replace("%3D", "=").replace("%2B", "+").replace("%24", "$")
+                .replace("%2C", ",").replace("%23", "#");
+    }
+
+    public  String getHtmlDiffString(String text1,String text2){
+        return diff_prettyHtml(diff_main(text1,text2));
+    }
+
+    public List<String> getHtmlDiffStr(String text1,String text2){
+        LinkedList<Diff> diffs = diff_main(text1, text2);
+        //定义输出结果
+        String LResultStr="";
+        String RResultStr="";
+        for(Diff deff:diffs){
+            String text = deff.text;
+//            String text = deff.text.replace("&", "&amp;").replace("<", "&lt;")
+//                    .replace(">", "&gt;").replace("\n", "<br/>");
+            switch (deff.operation) {
+                case INSERT:
+                    RResultStr+="<span class=\"insertClass\">"+text+"</span>";
+                    break;
+                case DELETE://删除  说明是左边有变化 右边没有变化
+                    LResultStr+="<span class=\"delClass\">"+text+"</span>";
+                    break;
+                case EQUAL:
+                    LResultStr+=text;
+                    RResultStr+=text;
+                    break;
+            }
+        }
+        List<String> result =new ArrayList<>();
+        result.add(LResultStr);
+        result.add(RResultStr);
+        return result;
+    }
+
+
+    public static void main(String[] args){
+        DiffUtils dmp = new DiffUtils();
+//        String text1 = "我方在“福市财政资金补助项目管理系统”的项目实施过程，为保证该项目的工程进度、zhiliang，符合数办项目的实施管理规范与要求。";
+//        String text2 = "我方在“福州市财政资金补助项目管理系统”的项目实施过程，为保证该项目的工程进度、质量，符合目的实施管理规范与要求。";
+        String str1="6转向系\n" +
+                "6.1汽车（三轮汽车除外）的方向盘应设置于左侧，其他机动车的方向盘不得设置于右侧；专项作业车、教练车按需要可设置左右两个方向盘。有驾驶室的正三轮摩托车如使用方向盘转向，则方向盘中心立柱距车辆纵向中心平面的水平距离应小于等于200 mm;其他摩托车不得使用方向盘转向。\n" +
+                "6.2机动车的方向盘（或方向把）应转动灵活，操纵方便，无卡滞现象。机动车应设置转向限位装置。转向系统在任何操作位置上，不得与其他部件有干涉现象。\n" +
+                "6.3机动车（摩托车、三轮汽车、手扶拖拉机运输机组除外）正常行驶时，转向轮转向后应有一定的回正能力（允许有残余角），以使机动车具有稳定的直线行驶能力。\n" +
+                "6.4机动车方向盘的最大自由转动量应小于或等于：\n" +
+                "a) 最大设计车速大于或等于100 km/h 的机动车：15°\n" +
+                "b) 三轮汽车：35°；\n" +
+                "c) 其他机动车：25° 。\n" +
+                "6.5汽车（三轮汽车除外）应具有适度的不足转向特性。\n" +
+                "6.6三轮汽车、摩托车的转向轮向左或向右转角应小于等于：\n" +
+                "a）\t三轮汽车、三轮摩托车、正三轮轻便摩托车:45°;\n" +
+                "6）\t\t两轮普通摩托车、两轮轻便摩托车:48°。\n" +
+                "6.6机动车在平坦、硬实、干燥和清洁的道路上行驶不应跑偏，其方向盘（或方向把）不应有摆振、路感不灵或其他异常现象。\n" +
+                "6.8机动车在平坦、硬实、干燥和清洁的水泥或沥青道路上行驶，以10 km/h的速度在5 s之内沿螺旋线从直线行驶过渡到外圆直径为25 m的车辆通道圆行驶，施加于方向盘外缘的最大切向力应小于等于245 N。\n" +
+                "6.9专用校车应采用转向助力装置;其他机动车转向轴最大设计轴荷大于4 000 kg时，也应采用转向助力装置。装有转向助力装置的机动车，转向时其转向助力功能不得出现时有时无的现象，且转向助力装置失效时仍应具有用方向盘控制机动车的能力。装有电动转向助力装置的汽车，在产品使用说明书规定的正常使用状态下，应保证转向助力装置的电能供应。\n" +
+                "6.10汽车和汽车列车（不计具有作业功能的专用装置的突出部分）、轮式拖拉机运输机组应能在同一个车辆通道圆内通过，车辆通道圆的外圆直径认为25.00 m，车辆通道圆的内圆直径D2为10.60 m。 汽车和汽车列车、轮式拖拉机运输机组由直线行驶过渡到上述圆周运动时，任何部分超出直线行驶时的 车辆外侧面垂直面的值（外摆值）应小于等于0.80 m（对铰接客车和铰接式无轨电车外摆值应小于等于 1.20 m），其试验方法见GB 1589。\n" +
+                "6.11汽车（三轮汽车除外）的车轮定位应与该车型的技术要求一致。对前轴采用非独立悬架的汽车（前轴采用双转向轴时除外），其转向轮的横向侧滑量，用侧滑台检验时侧滑量值应在±5 m/km之间。\n" +
+                "6.12转向节及臂，转向横、直拉杆及球销不得有裂纹和损伤，并且转向球销不应松旷。对机动车进行改装或修理时横、直拉杆不得拼焊。\n" +
+                "6.13三轮汽车、摩托车的前减振器、上下联板和方向把不应有变形和裂损。\n";
+        String str2="6转向系\n" +
+                "6.1汽车（三轮汽车除外）的方向盘应设置于左侧，其他机动车的方向盘不应设置于右侧；专项作业车、教练车按需要可设置左右两个方向盘。装有两个后轮、有驾驶室的正三轮摩托车如使用方向盘转向，则方向盘中心立柱距车辆纵向中心平面的水平距离应小于或等于200 mm ；其他摩托车不应使用方向盘转向。\n" +
+                "6.2机动车的方向盘（或方向把）应转动灵活，无卡滞现象。机动车应设置转向限位装置。转向系统在任何操作位置上，不应与其他部件有干涉现象。\n" +
+                "6.3机动车（摩托车、三轮汽车、手扶拖拉机运输机组除外〉正常行驶时，转向轮转向后应有一定的回正能力（允许有残余角），以使机动车具有稳定的直线行驶能力0\n" +
+                "6.4机动车方向盘的最大自由转动量应小于或等于：\n" +
+                "a) 最大设计车速大于或等于100 km/h 的机动车：15°\n" +
+                "b) 三轮汽车：35°；\n" +
+                "c) 其他机动车：25° 。\n" +
+                "6.5汽车（三轮汽车除外）应具有适度的不足转向特性。\n" +
+                "6.6三轮汽车、摩托车的转向轮向左或向右转角应小于或等于：\n" +
+                "a) 三轮汽车、三轮摩托车、正三轮轻便摩托车：45°；\n" +
+                "b）两轮普通摩托车、两轮轻便摩托车：48°0\n" +
+                "6.7机动车在平坦、硬实、干燥和清洁的道路上行驶不应跑偏，其方向盘（或方向把）不应有摆振等异常现象。\n" +
+                "6.8机动车在平坦、硬实、干燥和清洁的水泥或沥青道路上行驶，以10 km/h 的速度在5 s 之内沿螺旋线从直线行驶过渡到外圆直径为25m 的车辆通道圆行驶，施加于方向盘外缘的最大切向力应小于或等于245 N。\n" +
+                "6.9汽车（三轮汽车除外）的车轮定位应与该车型的技术要求一致。对前轴采用非独立悬架的汽车（前轴采用双转向轴时除外），其转向轮的横向侧滑量，用侧滑台检验时侧滑量值应小于或等于5 m/km。\n" +
+                "6.10 专用校车应采用转向助力装置；其他机动车转向轴最大设计轴荷大于4 000 kg 时，也应采用转向助力装置。装有转向助力装置的机动车，转向时其转向助力功能不应出现时有时无的现象，且转向助力装置失效时仍应具有用方向盘控制机动车的能力。\n" +
+                "6.11转向节及臂，转向横、直拉杆及球销应连接可靠，且不应有裂纹和损伤，并且转向球销不应松旷。对机动车进行改装或修理时横、直拉杆不应拼焊。\n" +
+                "6.12三轮汽车、摩托车的前减振器、上下联板和方向把不应有变形和裂损。";
+        String line1="6.1汽车（三轮汽车除外）的方向盘应设置于左侧，其他机动车的方向盘不得设置于右侧；专项作业车、教练车按需要可设置左右两个方向盘。有驾驶室的正三轮摩托车如使用方向盘转向，则方向盘中心立柱距车辆纵向中心平面的水平距离应小于等于200 mm;其他摩托车不得使用方向盘转向。";
+        String line2="6.1汽车（三轮汽车除外）的方向盘应设置于左侧，其他机动车的方向盘不应设置于右侧；专项作业车、教练车按需要可设置左右两个方向盘。装有两个后轮、有驾驶室的正三轮摩托车如使用方向盘转向，则方向盘中心立柱距车辆纵向中心平面的水平距离应小于或等于200 mm ；其他摩托车不应使用方向盘转向。";
+        String compareStr = dmp.getHtmlDiffString(str1,str2);
+        //String compareStr = dmp.getHtmlDiffString(line1,line2);
+        System.out.println(compareStr);
+        System.out.println("---------------------------------------------------");
+        List<String> htmlDiffStr = dmp.getHtmlDiffStr(str1, str2);
+        System.out.println(htmlDiffStr.get(0));
+        System.out.println("==============================================");
+        System.out.println(htmlDiffStr.get(1));
+    }
+}