【日拱一卒】动态代理使用示例

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

public class ProxyDemo {
    public static void main(String[] args) {
        HelloImpl hello = new HelloImpl();
        MyInvocationHandler myInvocationHandler = new MyInvocationHandler(hello);
        Hello o = (Hello) Proxy.newProxyInstance(HelloImpl.class.getClassLoader(), HelloImpl.class.getInterfaces(), myInvocationHandler);
        o.sayHello();
    }
}

interface Hello {
    void sayHello();
}

class HelloImpl implements Hello {
    @Override
    public void sayHello() {
        System.out.println("Hello World");
    }
}

class MyInvocationHandler implements InvocationHandler {
    private Object target;

    public MyInvocationHandler(Object target) {
        this.target = target;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("Invoking sayHello");
        Object result = method.invoke(target, args);
        return result;
    }
}