Spring AOP

 1 <dependency>
 2 　　<groupId>org.aspectj</groupId>
 3 　　<artifactId>aspectjrt</artifactId>
 4 　　<version>1.8.1</version>
 5 </dependency>
 6 <dependency>
 7 　　<groupId>org.aspectj</groupId>
 8 　　<artifactId>aspectjweaver</artifactId>
 9 　　<version>1.8.1</version>
10 </dependency>

 1 public interface UserDao {
 2     public String findUserById(int id);
 3 }
 4 
 5 public class UserDaoImpl implements UserDao {
 6     public String findUserById(int id) {
 7         if(id < 0) {
 8             throw new IllegalArgumentException("用户id不能小于0");
 9         }
10          return "zang";
11     }
12 }

 1 public class XMLAspect {
 2     private void doBefore(JoinPoint joinPoint) {
 3          System.out.println("-----doBefore().invoke-----");  
 4          System.out.println(" 此处意在执行核心业务逻辑前，做一些安全性的判断等等");  
 5          System.out.println(" 可通过joinPoint来获取所需要的内容");  
 6          System.out.println("-----End of doBefore()------");  
 7     }
 8     
 9     private Object doAround(ProceedingJoinPoint joinPoint) throws Throwable {
10         System.out.println("-----doAround().invoke-----");  
11         System.out.println(" 此处可以做类似于Before Advice的事情");  
12           
13         //调用核心逻辑  
14         Object retVal = joinPoint.proceed();  
15           
16         System.out.println(" 此处可以做类似于After Advice的事情");  
17         System.out.println("-----End of doAround()------");  
18         return retVal;  
19     }
20     
21     private void doAfter(JoinPoint joinPoint) {
22         System.out.println("-----doAfter().invoke-----");  
23         System.out.println(" 此处意在执行核心业务逻辑之后，做一些日志记录操作等等");  
24         System.out.println(" 可通过joinPoint来获取所需要的内容");  
25         System.out.println("-----End of doAfter()------"); 
26     }
27     
28     private void doAfterReturning(JoinPoint joinPoint) {
29         System.out.println("-----doReturn().invoke-----");  
30         System.out.println(" 此处可以对返回值做进一步处理");  
31         System.out.println(" 可通过joinPoint来获取所需要的内容");  
32         System.out.println("-----End of doReturn()------");  
33     }
34     
35     private void doAfterThrowing(JoinPoint joinPoint,Throwable ex) {
36         System.out.println("-----doThrowing().invoke-----");  
37         System.out.println(" 错误信息："+ex.getMessage());  
38         System.out.println(" 此处意在执行核心业务逻辑出错时，捕获异常，并可做一些日志记录操作等等");  
39         System.out.println(" 可通过joinPoint来获取所需要的内容");  
40         System.out.println("-----End of doThrowing()------"); 
41     }
42 }

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans
 3     xmlns="http://www.springframework.org/schema/beans"
 4     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 5     xmlns:aop="http://www.springframework.org/schema/aop"
 6     xmlns:p="http://www.springframework.org/schema/p"
 7     xmlns:context="http://www.springframework.org/schema/context"
 8     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
 9                         http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
10                         http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
11     
12     <context:component-scan base-package="test"/>
13     
14     <bean id="userDao" class="dao.UserDaoImpl"></bean>
15     
16     <bean id="xmlAspect" class="aspect.XMLAspect"></bean>
17     
18     <aop:config>
19         <aop:aspect id="aspect" ref="xmlAspect">
20             <!-- 定义切入点,一个切入点可能横切多个业务组件 -->
21             <aop:pointcut expression="execution(* dao.*.find*(..))" id="pointcut"/>
22             
23             <!-- 定义切入点上的增强处理 -->
24             <aop:before method="doBefore" pointcut-ref="pointcut"/>
25             <aop:around method="doAround" pointcut-ref="pointcut"/>
26             <aop:after method="doAfter" pointcut-ref="pointcut"/>
27             <aop:after-returning method="doAfterReturning" pointcut-ref="pointcut"/>
28             <aop:after-throwing method="doAfterThrowing" pointcut-ref="pointcut" throwing="ex"/>
29         
30         </aop:aspect>
31     </aop:config>
32 
33     
34 </beans>

 1 public class SpringTest {
 2     public static void main(String[] args) {
 3         ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
 4         
 5         UserDao userDao = (UserDao)ac.getBean("userDao");  
 6         
 7         userDao.findUserById(1);  
 8           
 9         System.out.println("==================");  
10   
11         try {  
12             // 查不到数据，会抛异常，异常会被AfterThrowingAdvice捕获  
13             userDao.findUserById(-1);  
14         } catch (IllegalArgumentException e) {  
15         }  
16     }
17 }