Spring 动态代理万能工具类

public class ProxyInvocationHandler implements InvocationHandler {
    //代理谁
    private Object target;

    public void setTarget(Object target) {
        this.target = target;
    }

    //生成代理类
    public Object getProxy(){
        return Proxy.newProxyInstance(this.getClass().getClassLoader(),target.getClass().getInterfaces(),this);
    }

    //调用代理程序的执行方法
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        log(method.getName());
        Object result=method.invoke(target,args);
        return result;
    }

    public void log(String msg){
        System.out.println("执行了"+msg+"方法");
    }
}

public class Client {
    public static void main(String[] args) {
        //被代理对象，真实角色
        UserServiceImpl userService=new UserServiceImpl();
        //代理角色，不存在
        ProxyInvocationHandler pih = new ProxyInvocationHandler();
        //设置需要代理的对象
        pih.setTarget(userService);
        //动态生成代理类
        UserService proxy = (UserService) pih.getProxy();
        proxy.add();
    }
}