Spring动态代理

基于spring-aop-4.3.12.release

public class DefaultAopProxyFactory implements AopProxyFactory, Serializable {
    public DefaultAopProxyFactory() {
    }

    /**
    * 创建代理
    * 1.没有优化，不是代理目标类且不是用户提供的代理接口  ->  JDK代理
    * 2.否则;不是接口且目标类不是代理类                 ->  CGLIB
    * 3.否则;                                         ->  JDK代理
    */
    public AopProxy createAopProxy(AdvisedSupport config) throws AopConfigException {
        if (!config.isOptimize() && !config.isProxyTargetClass() 
                && !this.hasNoUserSuppliedProxyInterfaces(config)) {
            return new JdkDynamicAopProxy(config);
        } else {
            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.");
            } else {
                return (AopProxy)(!targetClass.isInterface() && !Proxy.isProxyClass(targetClass) ? 
                new ObjenesisCglibAopProxy(config) : new JdkDynamicAopProxy(config));
            }
        }
    }

    /**
    * 获取的代理接口为空或者，只有一个且是SpringProxy的子类
    * 即非用户提供的代理接口
    */
    private boolean hasNoUserSuppliedProxyInterfaces(AdvisedSupport config) {
        Class<?>[] ifcs = config.getProxiedInterfaces();
        return ifcs.length == 0 || ifcs.length == 1 && SpringProxy.class.isAssignableFrom(ifcs[0]);
    }
}