getObject方法式ProxyFactoryBean创建AOPProxy代理的入口方法
ProxyFactoryBean的getObject方法
public Object getObject() throws BeansException {
//初始化通知器链
initializeAdvisorChain();
//目标对象是单态模式
if (isSingleton()) {
return getSingletonInstance();
}
else {
if (this.targetName == null) {
logger.warn("Using non-singleton proxies with singleton targets is often undesirable. " +
"Enable prototype proxies by setting the 'targetName' property.");
}
//目标对象是原型模式
return newPrototypeInstance();
}
}
initializeAdvisorChain方法
private synchronized void initializeAdvisorChain() throws AopConfigException, BeansException {
//通知器链是否初始化完成的标识
//换句话说初始化工作只会发生在应用第一次通过ProxyFactoryBean去获取代理对象的时候
if (this.advisorChainInitialized) {
return;
}
//判断ProxyFactoryBean中配置的连接器列名名称不为空（参考上一节的配置文件）
if (!ObjectUtils.isEmpty(this.interceptorNames)) {
if (this.beanFactory == null) {
throw new IllegalStateException("No BeanFactory available anymore (probably due to serialization) " +
"- cannot resolve interceptor names " + Arrays.asList(this.interceptorNames));
}
//全局通知器不能是通知器链中最后一个，除非显式使用属性指定了目标
if (this.interceptorNames[this.interceptorNames.length - 1].endsWith(GLOBAL_SUFFIX) &&
this.targetName == null && this.targetSource == EMPTY_TARGET_SOURCE) {
throw new AopConfigException("Target required after globals");
}
//添加Advisor链的调用，通过interceptorNames属性进行配置.
for (String name : this.interceptorNames) {
if (logger.isTraceEnabled()) {
logger.trace("Configuring advisor or advice '" + name + "'");
}
if (name.endsWith(GLOBAL_SUFFIX)) {
if (!(this.beanFactory instanceof ListableBeanFactory)) {
throw new AopConfigException(
"Can only use global advisors or interceptors with a ListableBeanFactory");
}
addGlobalAdvisor((ListableBeanFactory) this.beanFactory,
name.substring(0, name.length() - GLOBAL_SUFFIX.length()));
}
else {
//加入命名的拦截器Advice
Object advice;
if (this.singleton || this.beanFactory.isSingleton(name)) {
//单态Advice.
advice = this.beanFactory.getBean(name);
}
else {
//原型Advice
advice = new PrototypePlaceholderAdvisor(name);
}
//添加通知器advisor
addAdvisorOnChainCreation(advice, name);
}
}
}
this.advisorChainInitialized = true;
}
getSingletonInstance方法
private synchronized Object getSingletonInstance() {
if (this.singletonInstance == null) {
//获取代理的目标源
this.targetSource = freshTargetSource();
//如果ProxyFactoryBean设置了自动探测接口属性，并且没有配置代理接口
//而且不是目标对象的直接代理类
if (this.autodetectInterfaces && getProxiedInterfaces().length == 0 && !isProxyTargetClass()) {
//根据AOP框架来判断需要代理的接口.
Class<?> targetClass = getTargetClass();
if (targetClass == null) {
throw new FactoryBeanNotInitializedException("Cannot determine target class for proxy");
}
//设置代理对象的接口
setInterfaces(ClassUtils.getAllInterfacesForClass(targetClass, this.proxyClassLoader));
}
super.setFrozen(this.freezeProxy);
//使用ProxyFactory生成需要的AOPProxy对象
this.singletonInstance = getProxy(createAopProxy());
}
return this.singletonInstance;
}
ProxyCreatorSupport生成AopProxy对象
protected final synchronized AopProxy createAopProxy() {
if (!this.active) {
activate();
}
//通过AopProxyFactory取得AopProxy,使用的是DefaultAopProxyFactory
return getAopProxyFactory().createAopProxy(this);
}
DefaultAopProxyFactory中生成AopProxy
public AopProxy createAopProxy(AdvisedSupport config) throws AopConfigException {
if (config.isOptimize() || config.isProxyTargetClass() || hasNoUserSuppliedProxyInterfaces(config)) {
Class<?> targetClass = config.getTargetClass();
if (targetClass == null) {
throw new AopConfigException("TargetSource cannot determine target class: " +
"Either an interface or a target is required for proxy creation.");
}
if (targetClass.isInterface() || Proxy.isProxyClass(targetClass)) {
//使用JDK动态代理
return new JdkDynamicAopProxy(config);
}
//使用Cglib动态代理
return new ObjenesisCglibAopProxy(config);
}
else {
//使用JDK动态代理
return new JdkDynamicAopProxy(config);
}
}
当目标对象是原型模式的时候同样最后也会去调用DefaultAopProxyFactory中生成AopProxy对象，到此AOPProxy对象就生成完成了。AOPProxy对象具体是通过JDK动态代理还是Cglib动态代理不在博文中进行解析。
