java 动态代理的使用

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1.接口Human.java

public interface Human {
	void say();
}

2.Human的实现类 Person

public class Person implements Human {

	@Override
	public void say() {
		System.out.println("haha");
	}

}

3.处理类

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

public class Hander implements InvocationHandler {
	private Object obj;
	public Hander(Object obj) {
		this.obj = obj;
	}
	public Hander() {
	}
	@Override
	public Object invoke(Object proxy, Method method, Object[] args)
			throws Throwable {
		System.out.println("before");
		method.invoke(obj, args);
		System.out.println("after");
		return null;
	}

}

4. 使用

import java.lang.reflect.Proxy;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Human i = (Human) Proxy.newProxyInstance(Thread.currentThread()
				.getContextClassLoader(), Person.class.getInterfaces(),
				new Hander(new Person()));
		i.say();
	}

}

5. 输出结果

before
haha
after