spring aop 2.0 编程

在spring2.0中，aop发生了很大的变化：
主要分为两大方面
1.支持简单的aop xml配置
2.支持@AspectJ的注释

先来看一看第一种情况：
申明一个aspect，在xml中的申明如下：

<aop:config>

<aop:aspect id="myAspect" ref="aBean">

...

</aop:aspect>

</aop:config>

<bean id="aBean" class="...">

...

</bean>

申明pointcut

<aop:config>

<aop:pointcut id="businessService"

expression="execution(* com.xyz.myapp.service.*.*(..))"/>

</aop:config>

申明advice

Before advice：

<aop:aspect id="beforeExample" ref="aBean">

<aop:before

pointcut-ref="dataAccessOperation"

method="doAccessCheck"/>

</aop:aspect>

After returning advice:

<aop:aspect id="afterReturningExample" ref="aBean">

<aop:after-returning

pointcut-ref="dataAccessOperation"

method="doAccessCheck"/>

...

</aop:aspect>

或者带有返回参数

<aop:aspect id="afterReturningExample" ref="aBean">

<aop:after-returning

pointcut-ref="dataAccessOperation"

returning="retVal"

method="doAccessCheck"/>

...

</aop:aspect>

After throwing advice：

<aop:aspect id="afterThrowingExample" ref="aBean">

<aop:after-throwing

pointcut-ref="dataAccessOperation"

method="doRecoveryActions"/>

...

</aop:aspect>

或者带有throwing

<aop:aspect id="afterThrowingExample" ref="aBean">

<aop:after-throwing

pointcut-ref="dataAccessOperation"

throwing="dataAccessEx"

method="doRecoveryActions"/>

...

</aop:aspect>

After (finally) advice：

<aop:aspect id="afterFinallyExample" ref="aBean">

<aop:after

pointcut-ref="dataAccessOperation"

method="doReleaseLock"/>

...

</aop:aspect>

Around advice：

<aop:aspect id="aroundExample" ref="aBean">

<aop:around

pointcut-ref="businessService"

method="doBasicProfiling"/>

...

</aop:aspect>

Advice parameters：

<aop:before

pointcut="Pointcuts.anyPublicMethod() and @annotation(auditable)"

method="audit"

arg-names="auditable"/>

对于引入接口（Introductions）：

<aop:aspect id="usageTrackerAspect" ref="usageTracking">

<aop:declare-parents

types-matching="com.xzy.myapp.service.*+",

implement-interface="UsageTracked"
default-impl=" service.tracking.DefaultUsageTracked"/>

<aop:before

pointcut="com.xyz.myapp.SystemArchitecture.businessService()

and this(usageTracked)"

method="recordUsage"/>

</aop:aspect>

前面主要介绍了如何通过xml实现aop编程，下面主要介绍如何通过@AspectJ来实现。
为了使@AspectJ 支持生效,
需要做以下步骤：
在xml中设置

<aop:aspectj-autoproxy/>

或者
在xml中加入
<bean class="org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator" />

声明 aspect

<bean id="myAspect" class="org.xyz.NotVeryUsefulAspect">

<!-- configure properties of aspect here as normal -->

</bean>

package org.xyz;

import org.aspectj.lang.annotation.Aspect;

@Aspect

public class NotVeryUsefulAspect {

}

声明 pointcut

@Pointcut("execution(* transfer(..))")

public void transfer() {}

声明 advice

Before advice:

@Before("com.xyz.myapp.SystemArchitecture.dataAccessOperation()")

public void doAccessCheck() {

// ...

}

After returning advice:

@AfterReturning("com.xyz.myapp.SystemArchitecture.dataAccessOperation()")

public void doAccessCheck() {

// ...

}

或者

@AfterReturning(
pointcut="com.xyz.myapp.SystemArchitecture.dataAccessOperation()",
returning="retVal")

public void doAccessCheck(Object retVal) {

// ...

}

After throwing advice：

@AfterThrowing("SystemArchitecture.dataAccessOperation()")

public void doRecoveryActions() {

// ...

}

或者

@AfterThrowing(

pointcut=" SystemArchitecture.dataAccessOperation()",

throwing="ex")

public void doRecoveryActions(DataAccessException ex) {

// ...

}

After (finally) advice：

@After("com.xyz.myapp.SystemArchitecture.dataAccessOperation()")

public void doReleaseLock() {

// ...

}

Around advice：

@Around("com.xyz.myapp.SystemArchitecture.businessService()")

public Object doBasicProfiling( ProceedingJoinPoint pjp) throws Throwable {

// start stopwatch

Object retVal = pjp.proceed();

// stop stopwatch

return retVal;

}

Advice parameters：

@Before("com.xyz.myapp.SystemArchitecture.dataAccessOperation() &&" + "args(account,..)" )

public void validateAccount(Account account) {

// ...

}

声明参数名称：

@Before(

value="com.xyz.lib.Pointcuts.anyPublicMethod() && " +

"@annotation(auditable)",

argNames="auditable" )

public void audit(Auditable auditable) {

AuditCode code = auditable.value();

// ...

}

Advice 排序：

一般以声明的方法次序为先后

不同的 Advice ，通过实现 Ordered 接口，来排序

Introductions

用于引入新的接口

@Aspect

public class UsageTracking {

@DeclareParents(value="com.xzy.myapp.service.*+",

defaultImpl=DefaultUsageTracked.class)

public static UsageTracked mixin;

@Before("com.xyz.myapp.SystemArchitecture.businessService() &&" +

"this(usageTracked)")

public void recordUsage(UsageTracked usageTracked) {

usageTracked.incrementUseCount();

}

}

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/ourife/archive/2007/06/07/1641797.aspx