jdk动态代理

Posted 2020-12-26 danial7777777

package proxy.jdk;

public interface UserDao {

    public void add();
    public void delete();
    
}

package proxy.jdk;

public class UserDaoimpl implements UserDao{

    @Override
    public void add() {
        // TODO Auto-generated method stub
        System.out.println("user add success！");
    }

    @Override
    public void delete() {
        // TODO Auto-generated method stub
        System.out.println("user delete success！");
    }

}

package proxy.jdk;

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

public class Handler implements InvocationHandler{

    public Object target;
    
    public Handler(Object target) {
        super();
        this.target = target;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args)
            throws Throwable {
        // TODO Auto-generated method stub
        System.out.println("代理执行前");
        Object o = method.invoke(target, args);
        System.out.println("代理执行后");
        return o;
    }
    
    public Object getProxy() {
        return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(), target.getClass().getInterfaces(), this);
    }

}

package proxy.jdk;

public class Test {

    public static void main(String[] args) {
        
        UserDao userDao=new UserDaoimpl();
        Handler handler=new Handler(userDao);
        UserDao userProxy = (UserDao) handler.getProxy();
        userProxy.add();
        userProxy.delete();
        
    }
}