代理案例

1、

public interface MyService {
    public int add(int a , int b);
    public int sub(int a , int b);
}

2、实现类

/**
 * 实现类
 */
public class MyServiceImpl implements MyService,YourService {
    public int add(int a, int b) {
        return a + b ;
    }
    public int sub(int a, int b) {
        return a - b;
    }
    public int multiply(int a, int b) {
        return a * b ;
    }
    public float divide(int a, int b) {
        return (float)a / b;
    }
    public int shiftLeft(int a, int b) {
        return a << b ;
    }
    public int shiftRight(int a, int b) {
        return a >> b ;
    }

    public int singleAnd(int a, int b) {
        return a & b;
    }
    
    public boolean doubleAnd(int a, int b) {
        return false && true;
    }
}

3、

public interface YourService {
    public int multiply(int a , int b);
    public float divide(int a , int b);
    public int shiftLeft(int a,int b);
    public int shiftRight(int a,int b);
    public int singleAnd(int a,int b);
    public boolean doubleAnd(int a,int b);
    
}

4、

public class ProxyMain {
    public static void main(String[] args) {
        System.out.println("ProxyMain.hashcode : " + ProxyMain.class.hashCode());
        MyServiceImpl s = new MyServiceImpl();    //目标对象
        System.out.println("s.hashcode : " + s.hashCode());
        TimeHandler h = new TimeHandler(s);        //处理器对象
        Class[] clazz = {MyService.class,YourService.class} ;//代理接口数组
        MyService ms = (MyService) Proxy.newProxyInstance(ProxyMain.class.getClassLoader(), clazz, h);
        System.out.println(ms.add(2 , 2));
        System.out.println(((YourService)ms).multiply(2,2));
        System.out.println(ms.sub(2 , 2));
        System.out.println(((YourService)ms).shiftLeft(1,2));
        System.out.println(((YourService)ms).shiftRight(4,2));
        System.out.println(((YourService)ms).singleAnd(4,2));
        System.out.println(((YourService)ms).doubleAnd(4,2));
        System.out.println(((YourService)ms).divide(4, 4));
        System.out.println(((YourService)ms).divide(4, 4));
    }
    
    /**
     * 时间处理器
     */
    static class TimeHandler implements InvocationHandler{
        //目标对象
        private Object target;
        
        public TimeHandler(Object target){
            this.target = target ;
        }
        
        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
            long start = System.nanoTime() ;
            //调用目标对象的方法
            Object retVal = method.invoke(target, args);
            System.out.println(method.getName() + " : " + (System.nanoTime() - start));
            //切记:返回目标对象方法的返回值，否则篡改了业务逻辑。
            return retVal;
        }
    }
}