| /* |
| * 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 |
| * |
| * 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, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| package org.apache.tools.ant.util; |
| |
| |
| import java.lang.ref.WeakReference; |
| |
| /** |
| * These classes are part of some code to reduce memory leaks by only |
| * retaining weak references to things |
| * on Java1.2+, and yet still work (with leaky hard references) on Java1.1. |
| * Now that Ant is 1.2+ only, |
| * life is simpler and none of the classes are needed any more. |
| * |
| * They are only retained in case a third-party task uses them |
| * @since ant1.6 |
| * @see org.apache.tools.ant.util.optional.WeakishReference12 |
| * @deprecated deprecated 1.7; will be removed in Ant1.8 |
| * Just use {@link java.lang.ref.WeakReference} directly. |
| */ |
| public class WeakishReference { |
| |
| |
| private WeakReference weakref; |
| |
| /** |
| * create a new soft reference, which is bound to a |
| * Weak reference inside |
| * |
| * @param reference |
| * @see java.lang.ref.WeakReference |
| */ |
| WeakishReference(Object reference) { |
| this.weakref = new WeakReference(reference); |
| } |
| |
| /** |
| * Returns this reference object's referent. If this reference object has |
| * been cleared, then this method returns <code>null</code>. |
| * |
| * @return The object to which this reference refers, or |
| * <code>null</code> if this reference object has been cleared. |
| */ |
| public Object get() { |
| return weakref.get(); |
| } |
| |
| /** |
| * create the appropriate type of reference for the java version |
| * @param object the object that the reference will refer to. |
| * @return reference to the Object. |
| */ |
| public static WeakishReference createReference(Object object) { |
| return new WeakishReference(object); |
| } |
| |
| |
| /** |
| * This was a hard reference for Java 1.1. Since Ant1.7, |
| * @deprecated since 1.7. |
| * Hopefully nobody is using this. |
| */ |
| public static class HardReference extends WeakishReference { |
| |
| /** |
| * constructor. |
| * @param object the object that the reference will refer to. |
| */ |
| public HardReference(Object object) { |
| super(object); |
| } |
| |
| } |
| |
| } |