001 /* 002 * Copyright (C) 2007 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017 package com.google.common.base; 018 019 import java.lang.ref.ReferenceQueue; 020 import java.lang.ref.SoftReference; 021 022 /** 023 * Soft reference with a {@code finalizeReferent()} method which a background thread invokes after 024 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link 025 * ReferenceQueue}. 026 * 027 * @author Bob Lee 028 * @since 2 (imported from Google Collections Library) 029 */ 030 public abstract class FinalizableSoftReference<T> extends SoftReference<T> 031 implements FinalizableReference { 032 /** 033 * Constructs a new finalizable soft reference. 034 * 035 * @param referent to softly reference 036 * @param queue that should finalize the referent 037 */ 038 protected FinalizableSoftReference(T referent, FinalizableReferenceQueue queue) { 039 super(referent, queue.queue); 040 queue.cleanUp(); 041 } 042 }