Spring AOP基于XML的After Throwing Advice
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2023-03-14
after-throwing
是一种通知类型,只有在方法通过抛出异常退出时才能确保方法执行后才能运行通知。 以下是after-throwing
通知的语法:
语法
<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
- 切入点的id。ex
- 要被被抛出例外。methodName
- 在调用函数之前调用的函数的方法名称。
要了解上述与之后抛出通知(After Throwing Advice)相关的概念,写一个在实现之后抛出通知(After Throwing Advice)的示例。为了简单,可直接复制之前上一篇文章中的例子,打开并使用Eclipse IDE,并按照以下步骤创建一个Spring应用程序:
- 更新在Spring AOP应用实例中创建过的
Student
项目。 - 更新bean配置并运行应用程序,如下所述。
整个项目的目录结构如下所示 -
下面是Logging.java
文件的内容。 这实际上是一个Aspect
模块的样本,它定义了在各个点被调用的方法。
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文件的内容:
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
文件的内容:
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文件的内容:
<?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>
运行项目
完成创建源代码和配置文件后,运行应用程序。右键单击应用程序中的MainApp.java
,并使用运行方式作为Java应用程序命令。 如果您的应用程序一切正常,这将打印以下消息:
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)