整理：Java动态代理

public interface IPerson {
    public void say();
    public void run();
    public void sleep();
}

2.实现业务接口

public class PersonImpl implements IPerson {
    @Override
    public void say() {
        LogUtil.e("Person say");
    }

    @Override
    public void run() {
        LogUtil.e("Person run");
    }

    @Override
    public void sleep() {
        LogUtil.e("Person sleep");
    }
}

3.定义一个动态代理类，实现InvocationHandler接口

public class PersonHandle implements InvocationHandler {
    private Object object;//保持代理的原始对象

    public PersonHandle(Object object) {
        super();
        this.object = object;//构造注入
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        Object result=null;

        //如果是say方法，就有前置操作和后置操作
        if(method.getName().equals("say")){
            doBefore();
            result=method.invoke(object,args);
            doAfter();
        }

        //如果是run方法，就只有后置操作
        else if(method.getName().equals("run")){
            result=method.invoke(object,args);
            doAfter();
        }

        //如果是sleep方法，就啥都不干
        else if(method.getName().equals("run")){

        }
        return result;
    }

    private void doBefore() {
        LogUtil.e("before method invoke");
    }

    private void doAfter() {
        LogUtil.e("after method invoke");
    }
}

4.场景类

public class TestClient extends InstrumentationTestCase {

    public void testMain() {
        LogUtil.e("TestClient:[START]");

        IPerson person=new PersonImpl();
        InvocationHandler handler=new PersonHandle(person);

        IPerson proxy= (IPerson) Proxy.newProxyInstance(person.getClass().getClassLoader(),person.getClass().getInterfaces(),handler);
        proxy.say();
        proxy.run();

        LogUtil.e("TestClient:[END]");
    }

}

5.运行结果