Spring AOP 注解实现

使用aspectj注解实现的AOP需要引入aspectj的lib

<dependency>
			<groupId>org.aspectj</groupId>
			<artifactId>aspectjrt</artifactId>
			<version>1.8.0</version>
		</dependency>
	    <dependency>
			<groupId>org.aspectj</groupId>
			<artifactId>aspectjweaver</artifactId>
			<version>1.8.0</version>
		</dependency>

1. 首先启用 Spring 对 @AspectJ 切面配置的支持

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:aop="http://www.springframework.org/schema/aop"
	xsi:schemaLocation="http://www.springframework.org/schema/beans 
	http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
	http://www.springframework.org/schema/context
	http://www.springframework.org/schema/context/spring-context-3.2.xsd
	http://www.springframework.org/schema/aop
	http://www.springframework.org/schema/aop/spring-aop-3.2.xsd">

	<!-- scan all beans and inject dependence -->
	<context:component-scan base-package="com.myproject"/>
	<aop:aspectj-autoproxy/>
</beans>

2.定义切面 Bean

@Component
@Aspect 
public class LogInterceptor {

	@Pointcut("execution (!void com.myproject.example.service..*(..))")  
	private void anyUnvoid(){}  
	
	@Pointcut("within(com.myproject.example.service..*)")  
	private void anyService(){}  
	
	@Pointcut("anyUnvoid() && anyService()")  
	private void anyUnvoidService(){}  
	
	@Before("anyUnvoidService() && args(username, password)")
	public void doBefore(String username, String password){
		System.out.println("doBefore: "+username);
	} 
	
	/**
	 * 第二种访问目标参数的方法。<br>
	 * 将第一个参数定义为 JoinPoint 类型，当该增强处理方法被调用时，
	 * 该 JoinPoint 参数就代表了织入增强处理的连接点。
	 */
	@Before("anyUnvoidService()")
	public void doBefore2(JoinPoint jp){
		Object[] args = jp.getArgs();
		System.out.println("doBefore2: " +args[0]);
	} 
	
	@AfterReturning(pointcut="anyUnvoidService()", returning="result")
	public void doAfterRunning(String result){
		System.out.println("doAfterReturning:" +result);
	}

	@AfterReturning(pointcut="execution(* com.myproject.example.service.AccountService.Login(..))", returning="result")	
public void doAfterLogin(JoinPoint jp, Account result){
		if(result!=null)
			System.out.println(result.getUsername() +" login success.");
		else
			System.out.println(jp.getArgs()[0] +" login fail.");
	}
	
	@AfterThrowing(pointcut="anyUnvoidService()", throwing="ex")
	public void doAfterThrowing(Throwable ex){
		System.out.print("doAfterThrowing: "+ex.getMessage());
	}
	  
	@After("anyUnvoidService()")  
	public void doAfter(){  
		System.out.println("doAfter");
	}  
	
	/**
	 * Around 增强处理可替代所有其它增强处理。
	 * 它可改变执行目标方法的参数值，也可改变目标方法之后的返回值。 
	 */
	@Around("anyUnvoidService()")
	public Object doAround(ProceedingJoinPoint pjp) throws Throwable{
		Object[] args = pjp.getArgs(); //obtain arguements
		System.out.println("enter method: "+args[0]);
		Object result = pjp.proceed();
		System.out.println("exit method");
		return result;
	}

}

3. 目标Bean

@Service
public class AccountService {
	
	@Resource
	private AccountDao accountDao;
	
	public Account Login(String username, String password){
		System.out.println(username + " want  to login.");
		return null;
	}
	

}

4 测试

	@Test
	public void test(){
		ApplicationContext ac=new ClassPathXmlApplicationContext("spring.xml");
		AccountService accountService =(AccountService)ac.getBean("accountService");
		accountService.Login("Peter", "wetwe");
	}

测试结果：
enter method: Peter
doBefore: Peter
doBefore2: Peter
Peter want  to login.
exit method
doAfter
doAfterReturning:null