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