public class InvocationHandlerProxy implements InvocationHandler {

    //被代理的接口

    private Object target;

    //获取代理角色

    public void setTarget(Object target){

        this.target = target;

    }

    //获得一个代理类

    public Object getProxy(){

        return Proxy.newProxyInstance(this.getClass().getClassLoader(), target.getClass().getInterfaces(), this);

    }

    //处理代理实例，并返回结果

    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

        log();

        Object o = method.invoke(this.target, args);

        return o;

    }

    private void log(){

        System.out.println("执行前日志");

    }

}

//真实角色-被代理对象

        Landlord landlord = new Landlord();

        //实例化代理实例类

        InvocationHandlerProxy handlerProxy = new InvocationHandlerProxy();

        //设置要代理的对象

        handlerProxy.setTarget(landlord);

        //生成代理类InvocationHandlerProxy，以被代理对象的接口强转

        Sent proxy = (Sent) handlerProxy.getProxy();

        //代理真实操作

        proxy.rest();