Fixed: Add converter for StringWrapper and StringBuffer

(OFBIZ-5028)
To escape exception on native conversion, we add converter for StringBuffer and StringWrapper on MiscConverters
Thanks to Christoph Neuroth for this issue

git-svn-id: https://svn.apache.org/repos/asf/ofbiz/ofbiz-framework/trunk@1857371 13f79535-47bb-0310-9956-ffa450edef68

framework/base/src/main/java/org/apache/ofbiz/base/conversion/MiscConverters.java

@@ -30,6 +30,7 @@
 import java.util.UUID;
 import java.util.regex.Pattern;
 
+import org.apache.ofbiz.base.util.StringUtil;
 import org.apache.ofbiz.base.util.UtilGenerics;
 import org.apache.ofbiz.base.util.UtilMisc;
 
@@ -298,6 +299,26 @@ public Charset convert(String obj) throws ConversionException {
         }
     }
 
+    public static class StringBufferToString extends AbstractConverter<StringBuffer, String> {
+        public StringBufferToString() {
+            super(StringBuffer.class, String.class);
+        }
+
+        public String convert(StringBuffer obj) throws ConversionException {
+            return obj.toString();
+        }
+    }
+
+    public static class StringWrapperToString extends AbstractConverter<StringUtil.StringWrapper, String> {
+        public StringWrapperToString() {
+            super(StringUtil.StringWrapper.class, String.class);
+        }
+
+        public String convert(StringUtil.StringWrapper obj) {
+            return obj.toString();
+        }
+    }
+
     public static class UUIDToString extends AbstractConverter<UUID, String> {
         public UUIDToString() {
             super(UUID.class, String.class);