Remove sensitivity to encoding hashtable ordering by accepting only the first mapping seen for each key. Relies on encodings.properties putting the preferred java name first (equivalent to its current rule that when multipel mime names are given, the first is preferred).

Author: kubycsolutions

serializer/src/main/java/org/apache/xml/serializer/Encodings.java

@@ -36,6 +36,12 @@
 /**
  * Provides information about encodings. Depends on the Java runtime
  * to provides writers for the different encodings.
+ *
+ * NOTE: When a Java or MIME names appears more than once in the
+ * encodings.properties table, priority is given to the first instance
+ * seen. For example, MIME name ISO-8859-1 will be mapped to Java name
+ * ISO8859-1, even though the file includes synonyms such as ISO8859_1
+ * and 8859-1.
  * <p>
  * This class is not a public API. It is only public because it
  * is used outside of this package.
@@ -369,9 +375,9 @@ private static EncodingInfo[] loadEncodingInfo()
                         mimeName = st.nextToken();
                         EncodingInfo ei = new EncodingInfo(mimeName, javaName, highChar);
                         encodingInfo_list.add(ei);
-                        _encodingTableKeyMime.put(mimeName.toUpperCase(), ei);
+                        _encodingTableKeyMime.putIfAbsent(mimeName.toUpperCase(), ei);
                         if (first)
-                            _encodingTableKeyJava.put(javaName.toUpperCase(), ei);
+                            _encodingTableKeyJava.putIfAbsent(javaName.toUpperCase(), ei);
                     }
                 }
             }

serializer/src/main/resources/org/apache/xml/serializer/Encodings.properties

@@ -37,6 +37,9 @@
 # Higher values above this char might be in the encoding, although in the 
 # case of this particular encoding there are no higher chars.
 #
+# NOTE: When a Java or MIME names appears more than once in this
+# table, priority is given to the first instance seen. For example,
+# MIME name ISO-8859-1 will be mapped to Java name ISO8859-1.
 #
 # <JAVA name encoding>, <PREFERRED name MIME>
 #