Spring学习笔记（三）

Spring学习笔记（三）

AOP

一、使用Annotation方式实现AOP。步骤：

xml里加入配置：<aop:aspectj-autoproxy />

<?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:aop="http://www.springframework.org/schema/aop"
xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

<context:annotation-config />
<context:component-scan base-package="com.wangj.spring" />
<aop:aspectj-autoproxy />

</beans>

再引入如下jar包:

(注意：必须引入第三个jar)

@Aspect注解这个类

@Before @After等来注解方法

写明切入点（execution(...)）

将拦截器类交给Spring管理（@Component注解这个类）

@Aspect
@Component
public class LogInterceptor {
@Before("execution(public void com.wangj.spring.dao.impl.UserDaoImpl.save(com.wangj.spring.model.User))")
public void before() {
System.out.println("method before");
}

@After("execution(public void com.wangj.spring.dao.impl.UserDaoImpl.save(com.wangj.spring.model.User))")
public void after() {
System.out.println("method after(finally)");
}
}

二、织入点语法

execution(public * *(..)) // 作用于任何类任何方法
execution(* set*(..)) // 作用于任何以set开头的方法
execution(* com.wangj.spring.dao.impl.UserDaoImpl.*(..)) //作用于UserDaoImpl类的所有方法
execution(* com.wangj.spring.dao..*.*(..)) //作用于com.wangj.spring.dao包（包括所有子包）里的所有类的所有方法
execution(public void com.wangj.spring.dao.impl.UserDaoImpl.save(com.wangj.spring.model.User)) // 作用于UserDaoImpl类的save(User)方法

三、Annotation详解

　　1. @Pointcut 织入点集合

@Aspect
@Component
public class LogInterceptor {
@Pointcut("execution(* com.wangj.spring.dao..*.*(..))")
public void pointcutMethod() {}

//    @Before("execution(public void com.wangj.spring.dao.impl.UserDaoImpl.save(com.wangj.spring.model.User))")
@Before("pointcutMethod()")
public void before() {
System.out.println("method before");
}

//    @After("execution(public void com.wangj.spring.dao.impl.UserDaoImpl.save(com.wangj.spring.model.User))")
@After("pointcutMethod()")
public void after() {
System.out.println("method after(finally)");
}
}

　　2. @Before @After @AfterReturning @AfterThrowing @Around

@Aspect
@Component
public class LogInterceptor {
@Pointcut("execution(* com.wangj.spring.dao..*.*(..))")
public void pointcutMethod() {}

//    @Before("execution(public void com.wangj.spring.dao.impl.UserDaoImpl.save(com.wangj.spring.model.User))")
@Before("pointcutMethod()")
public void before() {
System.out.println("method before");
}

//    @After("execution(public void com.wangj.spring.dao.impl.UserDaoImpl.save(com.wangj.spring.model.User))")
@After("pointcutMethod()") // 方法执行完切入即使方法产生了异常
public void after() {
System.out.println("method after(finally)");
}

@AfterReturning("pointcutMethod()") // 方法正常执行完后切入
public void afterReturning() {
System.out.println("method afterReturning");
}

@AfterThrowing("pointcutMethod()") // 方法抛出异常时切入
public void afterThrowing() {
System.out.println("method afterThrowing");
}

@Around("myMethod()") // 环绕即在方法前、后都可以加逻辑
public void aroundMethod(ProceedingJoinPoint pjp) throws Throwable {
System.out.println("method around start");
pjp.proceed();
System.out.println("method around end");
}
}

四、使用XML方式实现AOP

<?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:aop="http://www.springframework.org/schema/aop"
xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

<context:annotation-config />
<context:component-scan base-package="com.wangj.spring" />
<!-- <aop:aspectj-autoproxy /> -->

<bean id="logInterceptor" class="com.wangj.spring.aop.LogInterceptor2"></bean>

<aop:config>
<aop:pointcut id="daoPointcut" expression="execution(public * com.wangj.spring.dao..*.*(..)))"></aop:pointcut>
<aop:aspect id="logAspect" ref="logInterceptor">
<!-- <aop:before method="before" pointcut="execution(public * com.wangj.spring.dao..*.*(..))" /> --> <!-- 不使用全局pointcut -->
<aop:before method="before" pointcut-ref="daoPointcut" />
<aop:after method="after" pointcut-ref="daoPointcut" />
<aop:after-returning method="afterReturning" pointcut-ref="daoPointcut" />
<aop:after-throwing method="afterThrowing" pointcut-ref="daoPointcut"/>
<aop:around method="aroundMethod" pointcut-ref="daoPointcut"/>
</aop:aspect>
</aop:config>

</beans>