jdk动态代理

实现步骤

1. 新建一个接口
2. 新建一个接口的实现类
3. 新建一个代理类，实现InvocationHandler接口，实现invoke方法-> method.invoke(…)
4. 在代理类中创建代理方法newProxy，传入目标对象，通过目标对象获取类加载器、类接口，调用Proxy.newProxyInstance方法获取代理对象
5. 通过代理对象调用具体方法

代码示例

新建一个接口

package com.demo.rpc.proxy;public interface NewsService {String queryById(long newsId);
}

新建一个接口的实现类

package com.demo.rpc.proxy;public class NewsServiceImpl implements NewsService {@Overridepublic void queryById(long newsId) {System.out.println("成龙亿元豪宅司法拍卖被撤回 原定于明日开拍 " + newsId);}
}

新建一个代理类

package com.demo.rpc.proxy;import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;public class JDKProxy implements InvocationHandler {Object targetObject;/*** 传入目标对象进行代理* @param targetObject* @return*/public Object newProxy(Object targetObject) {this.targetObject = targetObject;return Proxy.newProxyInstance(targetObject.getClass().getClassLoader(), targetObject.getClass().getInterfaces(), this);}@Overridepublic Object invoke(Object proxy, Method method, Object[] args) throws Throwable {System.out.println("代理之前");Object invoke = method.invoke(targetObject, args);System.out.println("代理之后");return invoke;}
}

调用测试

    @Testpublic void jdkProxy(){NewsServiceImpl newsServiceImpl = new NewsServiceImpl();JDKProxy proxy = new JDKProxy();NewsService newsService = (NewsService)proxy.newProxy(newsServiceImpl);newsService.queryById(1);}

cglib动态代理实现

实现步骤

1. 创建一个实现类
2. 新建一个代理类，实现MethodInterceptor接口，实现intercept方法-> method.invoke(…)
3. 在代理类创建代理方法newProxy并传入目标对象，通过Enhancer创建代理类
4. 通过代理对象调用具体方法

创建一个实现类

package com.demo.rpc.proxy;public class HelloService {public void sayHello(){System.out.println("hello");}
}

新建一个代理类

package com.demo.rpc.proxy;import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;import java.lang.reflect.Method;public class CGLIBProxy implements MethodInterceptor {Object targetObject;public Object newProxy(Object targetObject){this.targetObject = targetObject;Enhancer enhancer = new Enhancer();enhancer.setSuperclass(targetObject.getClass());enhancer.setCallback(this);Object proxyObj = enhancer.create();return proxyObj;}@Overridepublic Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {System.out.println("代理之前");Object invoke = method.invoke(targetObject, args);System.out.println("代理之后");return invoke;}
}

调用测试

    @Testpublic void CGLIBProxy(){CGLIBProxy proxy = new CGLIBProxy();HelloService helloService = (HelloService)proxy.newProxy(new HelloService());helloService.sayHello();}