package cn.reflect;

import java.lang.reflect.Method;

public class ReflectService {

    /**
     * 测试方法
     * @param name
     */
    public void testReflect(String name) {
        System.out.println("hello:"+name);
    }
    
    /**
     * 测试入口
     * @throws Exception 
     */
    public static void main(String[] args) throws Exception {
        
        /**
         * 通过反射创建ReflectService对象
         */
        Object service = Class.forName(ReflectService.class.getName()).newInstance();
        
        /**
         * 获取服务方法
         */
        Method method = service.getClass().getMethod("testReflect", String.class);
        
        method.invoke(service, "张三");
        
        
    }
    
}

package cn.reflect;

public interface HelloService {

    public void sayHello(String name);
}

package cn.reflect;

public class HelloServiceImpl implements HelloService {

    public void sayHello(String name) {
        // TODO Auto-generated method stub
        System.err.println("hello:"+name);
    }

}

package cn.reflect;

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

public class HelloServiceProxy implements InvocationHandler {
    
    /**
     * 真实服务对象
     */
    private Object target;
    
    public Object bind(Object target){
        this.target=target;
        /**
         * 取得代理对象
         */
        return Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(), this);//jdk代理对象需要提供接口
        
    }

    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        // TODO Auto-generated method stub
        
        System.out.println("我是JDK动态代理对象");
        
        Object result = null;
        
        /**
         * 反射方法调用前
         */
        System.out.println("我准备说hello");
        
        /**
         * 执行方法，相当于调用HelloServiceImpl中的sayHello方法
         */
        result = method.invoke(target, args);
        
        /**
         * 反射方法后调用
         */
        System.out.println("我说过hello了");
        
        return result;

    }

}

package cn.reflect;

public class HelloServiceMain {
    public static void main(String[] args) {
        
        HelloServiceProxy helloHandle = new HelloServiceProxy();
    
        HelloService proxy = (HelloService) helloHandle.bind(new HelloServiceImpl());
        proxy.sayHello("张三");
        
    }
}

package cn.reflect;

import java.lang.reflect.Method;

import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

public class HelloServiceCgLib implements MethodInterceptor{
    private Object target;

    /**
     * 创建代理对象
     */
    public Object getInstance(Object target) {
        
        this.target=target;
        Enhancer enHancer = new Enhancer();
        enHancer.setSuperclass(this.target.getClass());
        enHancer.setCallback(this);
        return enHancer.create();
        
    }
    
    
    public Object intercept(Object obj, Method method, Object[] arg, MethodProxy proxy) throws Throwable {
        // TODO Auto-generated method stub
        System.out.println("我是cglib代理对象");
        Object returnObj = proxy.invoke(obj, arg);
        
        /**
         * 反射方法前调用
         */
        System.out.println("我准备说hello");
        
        /**
         * 反射方法后调用
         */
        System.out.println("我说过hello了");
        
        return returnObj;
        
        
    }
    

    
    
}

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