1 files changed, 63 insertions, 26 deletions

diff --git a/src/com/sun/org/apache/xalan/internal/xsltc/compiler/util/MultiHashtable.java b/src/com/sun/org/apache/xalan/internal/xsltc/compiler/util/MultiHashtable.java
index adaee4f..9ef16a0 100644
--- a/src/com/sun/org/apache/xalan/internal/xsltc/compiler/util/MultiHashtable.java
+++ b/src/com/sun/org/apache/xalan/internal/xsltc/compiler/util/MultiHashtable.java
@@ -1,15 +1,15 @@
 /*
- * reserved comment block
- * DO NOT REMOVE OR ALTER!
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
  */
 /*
- * Copyright 2001-2004 The Apache Software Foundation.
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
+ *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -23,35 +23,72 @@
 
 package com.sun.org.apache.xalan.internal.xsltc.compiler.util;
 
-import java.util.Hashtable;
-import java.util.Vector;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
 
 /**
  * @author Jacek Ambroziak
  * @author Santiago Pericas-Geertsen
+ * @param <K>
+ * @param <V>
  */
-public final class MultiHashtable extends Hashtable {
+public final class MultiHashtable<K,V> {
     static final long serialVersionUID = -6151608290510033572L;
-    public Object put(Object key, Object value) {
-        Vector vector = (Vector)get(key);
-        if (vector == null)
-            super.put(key, vector = new Vector());
-        vector.add(value);
-        return vector;
+
+    private final Map<K, Set<V>> map = new HashMap<>();
+    private boolean modifiable = true;
+
+    /**
+     * Associates the specified key with a set of values. If the map previously
+     * contained a mapping for the key, the value is added to the set.
+     * @param key key with which the specified value is to be associated
+     * @param value value to be added to a set that is associated with the specified key
+     * @return the set that is associated with the specified key.
+     * @throw UnsupportedOperationException is the MultiHashtable is not modifiable.
+     */
+    public Set<V> put(K key, V value) {
+        if (modifiable) {
+            Set<V> set = map.get(key);
+            if (set == null) {
+                set = new HashSet<>();
+                map.put(key, set);
+            }
+            set.add(value);
+            return set;
+        }
+        throw new UnsupportedOperationException("The MultiHashtable instance is not modifiable.");
     }
 
-    public Object maps(Object from, Object to) {
-        if (from == null) return null;
-        final Vector vector = (Vector) get(from);
-        if (vector != null) {
-            final int n = vector.size();
-            for (int i = 0; i < n; i++) {
-                final Object item = vector.elementAt(i);
-                if (item.equals(to)) {
-                    return item;
+    /**
+     * Maps a key to a value in a set that is associated with the specified key.
+     * The mapping is performed by evaluating whether an item in the set equals
+     * the specified value.
+     *
+     * @param key key with which the specified value is to be associated
+     * @param value value in a set that is associated with the specified key
+     * @return the item in the set if a match is found.
+     */
+    public V maps(K key, V value) {
+        if (key == null) return null;
+        final Set<V> set = map.get(key);
+        if (set != null) {
+            for (V v : set) {
+                if (v.equals(value)) {
+                    return v;
                 }
             }
         }
         return null;
     }
+
+    /**
+     * Makes the MultiHashtable unmodifiable.  This method allows modules to set the table
+     * as "read-only" so that only query operation, that is maps, is allowed. Any attempts
+     * to modify the returned map result in an UnsupportedOperationException.
+     */
+    public void makeUnmodifiable() {
+        modifiable = false;
+    }
 }