after-throwing
是一種通知類型,只有在方法通過拋出異常退出時才能確保方法執(zhí)行后才能運行通知。 以下是after-throwing
通知的語法:
<aop:config>
<aop:aspect id="log" ref="logging">
<aop:pointcut id="pointcut-id" expression="execution( expression )"/>
<aop:after-throwing pointcut-ref="pointcut-id" throwing="ex" method="methodName"/>
</aop:aspect>
</aop:config>
在上面配置中,
pointcut-id
- 切入點的id。ex
- 要被被拋出例外。methodName
- 在調(diào)用函數(shù)之前調(diào)用的函數(shù)的方法名稱。要了解上述與之后拋出通知(After Throwing Advice)相關(guān)的概念,寫一個在實現(xiàn)之后拋出通知(After Throwing Advice)的示例。為了簡單,可直接復(fù)制之前上一篇文章中的例子,打開并使用Eclipse IDE,并按照以下步驟創(chuàng)建一個Spring應(yīng)用程序:
Student
項目。整個項目的目錄結(jié)構(gòu)如下所示 -
下面是Logging.java
文件的內(nèi)容。 這實際上是一個Aspect
模塊的樣本,它定義了在各個點被調(diào)用的方法。
package com.yiibai;
public class Logging {
/**
* This is the method which I would like to execute
* if there is an exception raised.
*/
public void afterThrowingAdvice(IllegalArgumentException ex){
System.out.println("[afterThrowingAdvice] There has been an exception: " + ex.toString());
}
}
以下是Student.java文件的內(nèi)容:
package com.yiibai;
public class Student {
private Integer age;
private String name;
public void setAge(Integer age) {
this.age = age;
}
public Integer getAge() {
System.out.println("Age : " + age );
System.out.println("Exception raised");
throw new IllegalArgumentException();
return age;
}
public void setName(String name) {
this.name = name;
}
public String getName() {
System.out.println("Name : " + name );
return name;
}
public void printThrowException(){
System.out.println("Exception raised");
throw new IllegalArgumentException();
}
}
以下是MainApp.java
文件的內(nèi)容:
package com.yiibai;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainApp {
public static void main(String[] args) {
ApplicationContext context =
new ClassPathXmlApplicationContext("Beans.xml");
Student student = (Student) context.getBean("student");
student.printThrowException();
}
}
以下是配置文件Beans.xml文件的內(nèi)容:
<?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"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd ">
<aop:config>
<aop:aspect id="log" ref="logging">
<aop:pointcut id="selectAll"
expression="execution(* com.yiibai.*.*(..))"/>
<aop:after-throwing pointcut-ref="selectAll" throwing="ex" method="afterThrowingAdvice"/>
</aop:aspect>
</aop:config>
<!-- Definition for student bean -->
<bean id="student" class="com.yiibai.Student">
<property name="name" value="maxsu" />
<property name="age" value="25" />
</bean>
<!-- Definition for logging aspect -->
<bean id="logging" class="com.yiibai.Logging"/>
</beans>
完成創(chuàng)建源代碼和配置文件后,運行應(yīng)用程序。右鍵單擊應(yīng)用程序中的MainApp.java
,并使用運行方式作為Java應(yīng)用程序命令。 如果您的應(yīng)用程序一切正常,這將打印以下消息:
Exception raised
[afterThrowingAdvice] There has been an exception: java.lang.IllegalArgumentException
Exception in thread "main" java.lang.IllegalArgumentException
at com.yiibai.Student.printThrowException(Student.java:27)
at com.yiibai.Student$$FastClassBySpringCGLIB$$e9280b4b.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:58)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
at com.yiibai.Student$$EnhancerBySpringCGLIB$$47620070.printThrowException(<generated>)
at com.yiibai.MainApp.main(MainApp.java:13)