Spring AOP (3)

实现原理：

环绕增强完成功能：在目标类的方法执行前后嵌入增强逻辑.
实现原理：
1. 实现接口 MethodInterceptor,重写函数 invoke ，在函数 invoke 前后实现需要插入目标方法之后的逻辑代码
2. 利用ProxyFactoryBean代理类调用目标类方法
3.配置Spring XML

定义接口类

package com.advice;import com.smart.domain.User;import java.sql.SQLException;/** * @author Duoduo * @version 1.0 * @date 2017/4/22 18:58 */public interface IUserDao {    int addUser(User user);    int updateUser(User user);    void deleteUser(User user);    void removeUser(User user) throws SQLException;}

接口实现类

package com.advice;import com.smart.domain.User;import java.sql.SQLException;/** * @author Duoduo * @version 1.0 * @date 2017/4/22 19:00 */public class UserDaoImpl implements IUserDao {    @Override    public int addUser(User user) {        System.out.println("Add user");        return 0;    }    @Override    public int updateUser(User user) {        System.out.println("Update user");        return 0;    }    @Override    public void deleteUser(User user) {        //throw new RuntimeException("exception test");    }    @Override    public void removeUser(User user) throws SQLException {        //throw new SQLException("SQLException Test");    }}

定义环绕增强类

package com.advice;import com.smart.domain.User;import org.aopalliance.intercept.MethodInterceptor;import org.aopalliance.intercept.MethodInvocation;/** * 环绕增强: 在目标类的方法前后嵌入增强逻辑 * @author Duoduo * @version 1.0 * @date 2017/4/23 09:59 */public class AddUserInterceptor implements MethodInterceptor {    @Override    public Object invoke(MethodInvocation invocation) throws Throwable {        //获取参数        Object[] args = invocation.getArguments();        User user = (User)args[0];        //在目标类执行方法之前执行 ...        System.out.println("AddUserInterceptor before execute add user");        //执行目标类的方法        Object object = invocation.proceed();        //在目标类执行方法之后执行 ...        System.out.println("AddUserInterceptor after execute add user");        return object;    }}

Spring XML 配置

特别注意：代理工厂是 ProxyFactoryBean 不是 ProxyFactory

<!-- 代理设置 --><bean id="userDaoImpl" class="com.advice.UserDaoImpl"/><bean id="addUserBeforAdvice" class="com.advice.AddUserBeforAdvice"/><bean id="addUserAfterAdvice" class="com.advice.AddUserAfterAdvice"/><bean id="addUserInterceptor" class="com.advice.AddUserInterceptor"/><bean id="addUserProxyFactory" class="org.springframework.aop.framework.ProxyFactoryBean"      p:proxyInterfaces="com.advice.IUserDao"      p:target-ref="userDaoImpl"      p:interceptorNames="addUserInterceptor"/>

两种调用方式：
1.根据XML配置来进行调用测试
2.自己创建代理来进行测试

另种方法都需要注意：此处代理获取的是代理Bean，指向的是Interface的代理。

@Testpublic  void addUserInterceptorTest(){    System.out.println("************ addUserInterceptorTest ************");    /*IUserDao userDao = new UserDaoImpl();    MethodInterceptor interceptor = new AddUserInterceptor();    //创建代理工厂    ProxyFactory proxyFactory = new ProxyFactory();    //设置代理目标类    proxyFactory.setTarget(userDao);    //为代理添加增强    proxyFactory.addAdvice(interceptor);    //生成代理实例    IUserDao proxyUserDao = (IUserDao)proxyFactory.getProxy();    proxyUserDao.addUser(user);*/    ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring-another-context.xml");    //代理为指向Interface的代理    IUserDao userDaoProxyFactory = (IUserDao) context.getBean("addUserProxyFactory");    userDaoProxyFactory.addUser(user);}

测试结果

四月 23, 2017 3:43:28 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@d4342c2: startup date [Sun Apr 23 15:43:28 CST 2017]; root of context hierarchy四月 23, 2017 3:43:28 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions信息: Loading XML bean definitions from class path resource [spring-another-context.xml]AddUserInterceptor before execute add userAdd userAddUserInterceptor after execute add user