Java实现动态代理

package com.oyy.mw.biz.i;

public interface Cal {
    
    public int add(int num1,int num2);
    public int sub(int num1,int num2);
    public int mul(int num1,int num2);
    public int div(int num1,int num2);
    
}

package com.oyy.mw.biz;

import com.oyy.mw.biz.i.Cal;

public class CalImpl implements Cal{

    public int add(int num1, int num2) {
        int result = num1+num2;
        return result;
    }

    public int sub(int num1, int num2) {
        int result = num1-num2;
        return result;
    }

    public int mul(int num1, int num2) {
        int result = num1*num2;
        return result;
    }

    public int div(int num1, int num2) {
        int result = num1/num2;
        return result;
    }

}

package com.oyy.mw.biz;

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

public class MyInvocationHandler implements InvocationHandler {
    
    Object obj = null;
    
    /**
     * @param obj 接受传入的真实对象
     * @return 返回代理对象
     */
    public Object bind(Object obj){
        this.obj = obj;
        return Proxy.newProxyInstance(obj.getClass().getClassLoader(), 
                obj.getClass().getInterfaces(),
                this);
    }
    
    public Object invoke(Object proxy, Method method, Object[] args)
            throws Throwable {
        System.out.println(method.getName()+"的参数是:"+Arrays.toString(args));
        //调用方法，返回该方法返回的结果
        Object result  = method.invoke(obj, args);
        System.out.println(method.getName()+"的结果是:"+result);

        return result;
    }

}

package com.oyy.mw.test;

import com.oyy.mw.biz.CalImpl;
import com.oyy.mw.biz.MyInvocationHandler;
import com.oyy.mw.biz.i.Cal;

public class Test {
    public static void main(String[] args) {
        Cal cal1 = new CalImpl();
        MyInvocationHandler handler  = new MyInvocationHandler();
        Cal cal = (Cal)handler.bind(cal1);
        cal.add(10, 3);
        
        cal.sub(10, 3);
        cal.mul(10, 3);
        cal.div(10, 3);
    }
}