<?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" >
<!-- Enable AspectJ style of Spring AOP -->
<aop:aspectj-autoproxy />
<bean id="studService" class="springAOP.Student">
<property name="age" value="20"></property>
<property name="name" value="Sangeetha"></property>
</bean>
<bean id="logging" class="springAOP.Logging"/>
<aop:config>
<aop:aspect id="log" ref="logging" >
<aop:pointcut id="student" expression="execution(* springAOP.Student.*(..))" />
<!-- before advice definition -->
<aop:before pointcut-ref="student" method="beforeAdvice"/>
<!-- after advice definition -->
<aop:after pointcut-ref="student" method="afterAdvice"/>
<!-- after-returning advice -->
<aop:after-returning pointcut-ref="student" method="afterReturningAdvice" returning="retVal"/>
<!-- after throwing advice -->
<aop:after-throwing pointcut-ref="student" method="afterThrowingAdvice" throwing="ex"/>
<!-- around advice -->
<aop:around pointcut-ref="student" method="aroundAdvice"/>
</aop:aspect>
</aop:config>
package spring;
import springAOP.Student;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class SpringApp {
private AbstractApplicationContext context;
HelloWorld obj;
Student student;
public SpringApp()
{
context = new ClassPathXmlApplicationContext("spring-beans.xml");
}
public void initializeBeans(){
obj = (HelloWorld)context.getBean("sayHello");
student = (Student)context.getBean("studService");
}
public static void main(String args[]){
SpringApp app = new SpringApp();
app.initializeBeans();
System.out.println(" getting name and age");
Student stud = (Student)app.context.getBean("studService");
stud.getName();
stud.getAge();
}
package springAOP;
public class Student {
private Integer age;
private String name;
public void setAge(Integer age) {
this.age = age;
System.out.println("Setting Age : " + age);
}
public Integer getAge() {
System.out.println("Age : " + age);
return age;
}
public void setName(String name) {
this.name = name;
System.out.println("Setting Name : " + name);
}
public String getName() {
System.out.println("Name : " + name);
return name;
}
public void printThrowException() {
System.out.println("Exception raised");
throw new IllegalArgumentException();
}
}
Jul 17, 2015 9:51:50 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@ad9418: startup date [Fri Jul 17 21:51:50 IST 2015]; root of context hierarchy
Jul 17, 2015 9:51:51 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring-beans.xml]
Jul 17, 2015 9:51:52 PM org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@e2abd: defining beans [org.springframework.aop.config.internalAutoProxyCreator,studService,logging,org.springframework.aop.aspectj.AspectJPointcutAdvisor#0,org.springframework.aop.aspectj.AspectJPointcutAdvisor#1,org.springframework.aop.aspectj.AspectJPointcutAdvisor#2,org.springframework.aop.aspectj.AspectJPointcutAdvisor#3,org.springframework.aop.aspectj.AspectJPointcutAdvisor#4,student,employee,employeeService,dataSource,sayHello,spellCheck]; root of factory hierarchy
Setting Age : 20
Setting Name : Sangeetha
Jul 17, 2015 9:51:53 PM org.springframework.jdbc.datasource.DriverManagerDataSource setDriverClassName
INFO: Loaded JDBC driver: oracle.jdbc.driver.OracleDriver
Setting Message is : you are in spring Hello World
i m in init
i 2 j 3
Going to setup student profile.
After smooth execution
Returning:null
Student profile has been setup.
Going to setup student profile.
After smooth execution
Returning:null ==> returning NULL
Student profile has been setup.
package springAOP;
public class Logging {
/**
* * This is the method which I would like to execute * before a selected
* method execution.
*/
public void beforeAdvice() {
System.out.println("Going to setup student profile.");
}
/**
* * This is the method which I would like to execute * after a selected
* method execution.
*/
public void afterAdvice() {
System.out.println("Student profile has been setup.");
}
/**
* * This is the method which I would like to execute * when any method
* returns.
*/
public void afterReturningAdvice(String retVal) {
System.out.println("Returning:" + retVal);
}
/**
* * This is the method which I would like to execute * if there is an
* exception raised.
*/
public void afterThrowingAdvice(IllegalArgumentException ex) {
System.out.println("There has been an exception: " + ex.toString());
}
public void aroundAdvice(){
System.out.println("After smooth execution " );
}
}
当访问getName和getAge方法时，afterReturning未获得retValue，值将传递为NULL。请帮助我理解为什么价值被传递为NULL
答案 0 :(得分：0)
您可以使用aspectJ的ProceedingJoinPoint。
public void afterReturningAdvice(ProceedingJoinPoint joinpoint) {
Object[] args = joinpoint.getArgs()
Object retVal = null;
if(args.length > 0) {
retVal = args[0];
}
System.out.println("Returning:" + retVal);
}