动态代理

基于接口动态代理 :Proxy

//接口:
public interface Sports {
    public void paly();
}

//接口实现类
public class Basketball implements Sports{
    @Override
    public void paly() {
        System.out.println("打篮球");
    }
}

public class Client_Main {
    public static void main(String[] args) {
        final Sports sports = new Basketball();
        Sports sports_Porxy = (Sports) Proxy.newProxyInstance(sports.getClass().getClassLoader(), sports.getClass().getInterfaces(), new InvocationHandler() {
            /**　　
             * @param proxy 指代我们所代理的那个真实对象
             * @param method 指代的是我们所要调用真实对象的某个方法的Method对象
             * @param args 指代的是调用真实对象某个方法时接受的参数
             * @return
             * @throws Throwable
             */
            @Override
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                System.out.println("先开始准备运动");
                Object obj = method.invoke(sports, args);
                return obj;
            }
        });

        sports_Porxy.paly();
    }
}

• 输出:
  先开始准备运动
  打篮球

基于类的动态代理 :CGLIB

• 前提:
  1. 被代理类不能被final修饰
  2. 必须是public

先要加入CGLIB架包:

<dependency>
           <groupId>cglib</groupId>
           <artifactId>cglib-nodep</artifactId>
           <version>3.2.4</version>
</dependency>

//类
public class FootBall {
    public void play(){
        System.out.println("踢足球");
    }
}

public class Client_Main_cglib {
    public static void main(String[] args) {
        final FootBall footBall = new FootBall();

        FootBall footBall_Proxy = (FootBall) Enhancer.create(footBall.getClass(), new MethodInterceptor() {
            @Override
            public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
                System.out.println("先开始准备运动");
                Object obj= method.invoke(footBall,objects);
                return obj;
            }
        });

        footBall_Proxy.play();
    }
}

• 输出:
  先开始准备运动
  踢足球