001/* 002 * Copyright 2002-2018 the original author or 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 * https://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 017package org.springframework.aop.framework; 018 019import java.util.LinkedList; 020import java.util.List; 021 022import org.springframework.util.Assert; 023 024/** 025 * Base class for proxy factories. 026 * Provides convenient access to a configurable AopProxyFactory. 027 * 028 * @author Juergen Hoeller 029 * @since 2.0.3 030 * @see #createAopProxy() 031 */ 032@SuppressWarnings("serial") 033public class ProxyCreatorSupport extends AdvisedSupport { 034 035 private AopProxyFactory aopProxyFactory; 036 037 private final List<AdvisedSupportListener> listeners = new LinkedList<AdvisedSupportListener>(); 038 039 /** Set to true when the first AOP proxy has been created */ 040 private boolean active = false; 041 042 043 /** 044 * Create a new ProxyCreatorSupport instance. 045 */ 046 public ProxyCreatorSupport() { 047 this.aopProxyFactory = new DefaultAopProxyFactory(); 048 } 049 050 /** 051 * Create a new ProxyCreatorSupport instance. 052 * @param aopProxyFactory the AopProxyFactory to use 053 */ 054 public ProxyCreatorSupport(AopProxyFactory aopProxyFactory) { 055 Assert.notNull(aopProxyFactory, "AopProxyFactory must not be null"); 056 this.aopProxyFactory = aopProxyFactory; 057 } 058 059 060 /** 061 * Customize the AopProxyFactory, allowing different strategies 062 * to be dropped in without changing the core framework. 063 * <p>Default is {@link DefaultAopProxyFactory}, using dynamic JDK 064 * proxies or CGLIB proxies based on the requirements. 065 */ 066 public void setAopProxyFactory(AopProxyFactory aopProxyFactory) { 067 Assert.notNull(aopProxyFactory, "AopProxyFactory must not be null"); 068 this.aopProxyFactory = aopProxyFactory; 069 } 070 071 /** 072 * Return the AopProxyFactory that this ProxyConfig uses. 073 */ 074 public AopProxyFactory getAopProxyFactory() { 075 return this.aopProxyFactory; 076 } 077 078 /** 079 * Add the given AdvisedSupportListener to this proxy configuration. 080 * @param listener the listener to register 081 */ 082 public void addListener(AdvisedSupportListener listener) { 083 Assert.notNull(listener, "AdvisedSupportListener must not be null"); 084 this.listeners.add(listener); 085 } 086 087 /** 088 * Remove the given AdvisedSupportListener from this proxy configuration. 089 * @param listener the listener to deregister 090 */ 091 public void removeListener(AdvisedSupportListener listener) { 092 Assert.notNull(listener, "AdvisedSupportListener must not be null"); 093 this.listeners.remove(listener); 094 } 095 096 097 /** 098 * Subclasses should call this to get a new AOP proxy. They should <b>not</b> 099 * create an AOP proxy with {@code this} as an argument. 100 */ 101 protected final synchronized AopProxy createAopProxy() { 102 if (!this.active) { 103 activate(); 104 } 105 return getAopProxyFactory().createAopProxy(this); 106 } 107 108 /** 109 * Activate this proxy configuration. 110 * @see AdvisedSupportListener#activated 111 */ 112 private void activate() { 113 this.active = true; 114 for (AdvisedSupportListener listener : this.listeners) { 115 listener.activated(this); 116 } 117 } 118 119 /** 120 * Propagate advice change event to all AdvisedSupportListeners. 121 * @see AdvisedSupportListener#adviceChanged 122 */ 123 @Override 124 protected void adviceChanged() { 125 super.adviceChanged(); 126 synchronized (this) { 127 if (this.active) { 128 for (AdvisedSupportListener listener : this.listeners) { 129 listener.adviceChanged(this); 130 } 131 } 132 } 133 } 134 135 /** 136 * Subclasses can call this to check whether any AOP proxies have been created yet. 137 */ 138 protected final synchronized boolean isActive() { 139 return this.active; 140 } 141 142}