【fix sonar】CustomDemoConverter文件

jero-boot/jero-boot-base/jero-boot-base-generater/src/main/java/com/jero/generater/modules/online/cgform/converter/CustomDemoConverter.java

@@ -1,18 +1,22 @@
 
 package com.jero.generater.modules.online.cgform.converter;
 
+import java.util.Collections;
 import java.util.Map;
 import org.springframework.stereotype.Component;
 
 @Component("customDemoConverter")
 public class CustomDemoConverter implements FieldCommentConverter {
     public CustomDemoConverter() {
+        // do other
     }
 
+    @Override
     public String converterToVal(String txt) {
         return txt != null && txt.equals("管理员1") ? "admin" : txt;
     }
 
+    @Override
     public String converterToTxt(String val) {
         if (val != null) {
             if (val.equals("admin")) {
@@ -27,7 +31,8 @@ public class CustomDemoConverter implements FieldCommentConverter {
         return val;
     }
 
+    @Override
     public Map<String, String> getConfig() {
-        return null;
+        return Collections.emptyMap();
     }
 }