前面主要介紹了如何通過xml實現aop編程，下面主要介紹如何通過@AspectJ來實現。
為了使@AspectJ 支持生效,
需要做以下步驟：
在xml中設置

<aop:aspectj-autoproxy/>

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

聲明 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 {

?

}

聲明 pointcut

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

public void transfer() {}

聲明 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) {

? // ...

}

聲明參數名稱：

@Before(

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

???????? "@annotation(auditable)",

? ?argNames="auditable" )

public void audit(Auditable auditable) {

? AuditCode code = auditable.value();

? // ...

}?

Advice 排序：

一般以聲明的方法次序為先后

不同的 Advice ，通過實現 Ordered 接口，來排序

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();

? }

?

}

?