(转)一个简单的Spring的AOP例子
经过这段日子的学习和使用Spring,慢慢地体会到Spring的优妙之处,正在深入地吸收Spring的精华,呵呵。现在写的这个只是个简单AOP例子,包括前置通知,后置通知,环绕通知,和目标对象。写这个例子的主要目标只是想让想学AOP的能更快地入门,了解一下如何去配置AOP里面的东东。
目标对象的接口:IStudent.java
/**
?*?
?*/
package?com.dragon.study;
/**
?*?@author?dragon
?*
?*/
public?interface?IStudent?{
????
????public?void?addStudent(String?name);
}
目标类:StudentImpl.java
/**
?*?
?*/
package?com.dragon.study.Impl;
import?com.dragon.study.IStudent;
/**
?*?@author?dragon
?*
?*/
public?class?StudentImpl?implements?IStudent{
?????public?void?addStudent(String?name){
?????????System.out.println("欢迎?"+name+"?你加入Spring家庭!");
?????}
}
前置通知:BeforeAdvice.java
/**
?*?
?*/
package?com.dragon.Advice;
import?java.lang.reflect.Method;
import?org.springframework.aop.MethodBeforeAdvice;
/**
?*?@author?dragon
?*
?*/
public?class?BeforeAdvice?implements?MethodBeforeAdvice{
??????public?void?before(Method?method,Object[]?args,?Object?target)
???????????????throws?Throwable{
??????????
??????????System.out.println("这是BeforeAdvice类的before方法.");
??????????
??????}
}
后置通知:AfterAdvice.java
/**
?*?
?*/
package?com.dragon.Advice;
import?java.lang.reflect.Method;
import?org.springframework.aop.AfterReturningAdvice;
/**
?*?@author?dragon
?*
?*/
public?class?AfterAdvice?implements?AfterReturningAdvice{
????
????public?void?afterReturning(Object?returnValue?,Method?method,
???????????????????Object[]?args,Object?target)?throws?Throwable{
????????System.out.println("这是AfterAdvice类的afterReturning方法.");
????}
??????
}
环绕通知:CompareInterceptor.java
/**
?*?
?*/
package?com.dragon.Advice;
import?org.aopalliance.intercept.MethodInterceptor;
import?org.aopalliance.intercept.MethodInvocation;

/**
?*?@author?dragon
?*
?*/
public?class?CompareInterceptor?implements?MethodInterceptor{
??????public?Object?invoke(MethodInvocation?invocation)?throws?Throwable{
??????????Object?result?=?null;
?????????String?stu_name?=?invocation.getArguments()[0].toString();
?????????if?(?stu_name.equals("dragon")){
?????????????//如果学生是dragon时,执行目标方法,
??????????????result=?invocation.proceed();
??????????????
?????????}?else{
?????????????System.out.println("此学生是"+stu_name+"而不是dragon,不批准其加入.");
?????????}
????????
??????????return?result;
??????}
}
配置文件applicationContext.xml
<?xml?version="1.0"?encoding="UTF-8"?>
<!DOCTYPE?beans?PUBLIC?"-//SPRING//DTD?BEAN//EN"?"http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean?id="beforeAdvice"?class="com.dragon.Advice.BeforeAdvice"></bean>
<bean?id="afterAdvice"?class="com.dragon.Advice.AfterAdvice"></bean>
<bean?id="compareInterceptor"?class="com.dragon.Advice.CompareInterceptor"></bean>
<bean?id="studenttarget"?class="com.dragon.study.Impl.StudentImpl"></bean>
<bean?id="student"?class="org.springframework.aop.framework.ProxyFactoryBean">
??<property?name="proxyInterfaces">
????<value>com.dragon.study.IStudent</value>
??</property>
??<property?name="interceptorNames">
????<list>
?????<value>beforeAdvice</value>
?????<value>afterAdvice</value>
????<value>compareInterceptor</value>??
????</list>
??</property>
??<property?name="target">
????<ref?bean="studenttarget"/>
??</property>
</bean>



</beans>
? 现在开始写测试类,Test.java
/**
?*?
?*/
package?com;
import?org.springframework.context.ApplicationContext;
import?org.springframework.context.support.FileSystemXmlApplicationContext;
import?com.dragon.study.IStudent;
/**
?*?@author?dragon
?*
?*/
public?class?Test?{
????/**
?????*?@param?args
?????*/
????public?static?void?main(String[]?args)?{
????????//?TODO?Auto-generated?method?stub
??????ApplicationContext?ctx?=?
??????????new?FileSystemXmlApplicationContext("/com/dragon/applicationContext.xml");
??????
??????IStudent?person?=?(IStudent)ctx.getBean("student");
??????person.addStudent("dragon");
??????
//??????person.addStudent("javadragon");
????}
}