Spring AspectJ AOP框架注解原理解析

 package cn.spring3.demo1; /** * @author NOP * 被代理的对象 */ public class UserDao { public void add() { // TODO Auto-generated method stub System.out.println("添加客户"); } public void delete() { // TODO Auto-generated method stub System.out.println("删除客户"); int i=1/0; } public String find() { // TODO Auto-generated method stub System.out.println("查询客户"); return "fanhuizhi"; } public void update() { // TODO Auto-generated method stub System.out.println("修改客户"); } }

 package cn.spring3.demo1; import org.aspectj.lang.JoinPoint; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.After; import org.aspectj.lang.annotation.AfterReturning; import org.aspectj.lang.annotation.AfterThrowing; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; import org.aspectj.lang.annotation.Pointcut; /** * @author NOP 切面类：就是切点与增强结合 * 前置增强 */ @Aspect public class MyAspect { @Before(value = "execution(* cn.spring3.demo1.UserDao.add(..))")//这里写表达式，写哪些类需要添加 public void before(JoinPoint joinpoint) { System.out.println("前置增强..."+joinpoint); } @AfterReturning(value = "execution(* cn.spring3.demo1.UserDao.find(..))",returning="returnVal")//这里写表达式，写哪些类需要添加 public void afterReturning(Object returnVal){ System.out.println("后置增强..."+"方法的返回值"+returnVal); } @Around(value = "execution(* cn.spring3.demo1.UserDao.delete(..))")//这里写表达式，写哪些类需要添加 public Object around(ProceedingJoinPoint proceedingJoinPoint) throws Throwable{ System.out.println("环绕前增强..."); Object obj = proceedingJoinPoint.proceed(); System.out.println("环绕后增强..."); return obj; } @AfterThrowing(value = "execution(* cn.spring3.demo1.UserDao.delete(..))",throwing="ex")//这里写表达式，写哪些类需要添加 public void afterThrowing(Throwable ex) throws Throwable{ System.out.println("不跑了出异常了..."+ex.getMessage()); } //@After(value = "execution(* cn.spring3.demo1.UserDao.delete(..))")//这里写表达式，写哪些类需要添加 @After("MyAspect.MyPointCut()")//类名.方法名 public void after(){ System.out.println("最终通知");//不管有没有异常都会通知 } //仅是为了定义一个通用的表达式 @Pointcut(value = "execution(* cn.spring3.demo1.UserDao.delete(..))") private void MyPointCut(){ } }

 xmlns:aop="http://www.springframework.org/schema/aop" * 引入aop的约束: *

 package cn.spring3.demo1; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4Cla***unner; /** * @author NOP * 自动方式代理没有切点切面的增强 */ @RunWith(SpringJUnit4Cla***unner.class) @ContextConfiguration("classpath:applicationContext.xml") public class SpringTest1 { @Autowired @Qualifier("userDao") private UserDao userDao; @Test public void demo1(){ System.out.println("-----------------"); userDao.add(); System.out.println("-----------------"); userDao.find(); System.out.println("-----------------"); userDao.delete(); System.out.println("-----------------"); userDao.update(); System.out.println("-----------------"); } } 测试结果： ----------------- 前置增强...execution(void cn.spring3.demo1.UserDao.add()) 添加客户 ----------------- 查询客户 后置增强...方法的返回值fanhuizhi ----------------- 环绕前增强... 删除客户 最终通知 不跑了出异常了.../ by zero

 package cn.spring3.demo2; public class ProductDao { public void add() { // TODO Auto-generated method stub System.out.println("添加商品"); } public void delete() { // TODO Auto-generated method stub System.out.println("删除商品"); } public void find() { // TODO Auto-generated method stub System.out.println("查询商品"); int i = 1 / 0; } public String update() { // TODO Auto-generated method stub System.out.println("修改商品"); return "woshitest"; } }

 package cn.spring3.demo2; import org.aspectj.lang.ProceedingJoinPoint; /** * @author NOP * 切面类 */ public class MyAspectXML { /* * */ public void before(){ System.out.println("前置增强"); } public void afterReturning(Object returnVal){ System.out.println("后置增强"+returnVal); } public Object around(ProceedingJoinPoint proceedingJoinPoint) throws Throwable{ System.out.println("环绕前增强"); Object obj = proceedingJoinPoint.proceed(); System.out.println("环绕后增强"); return obj; } public void afterThrowing(Throwable ex){ System.out.println("不跑了出异常了..."+ex.getMessage()); } public void after(){ System.out.println("最终通知");//不管有没有异常都会通知 } }

 package cn.spring3.demo2; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4Cla***unner; @RunWith(SpringJUnit4Cla***unner.class) @ContextConfiguration("classpath:applicationContext2.xml") public class SpringTest2 { @Autowired @Qualifier("productDao") private ProductDao productDao; @Test public void demo1(){ System.out.println("-----------------"); productDao.add(); System.out.println("-----------------"); productDao.find(); System.out.println("-----------------"); productDao.delete(); System.out.println("-----------------"); productDao.update(); System.out.println("-----------------"); } } 测试结果： ----------------- 前置增强 添加商品 ----------------- 查询商品 不跑了出异常了.../ by zero 最终通知