(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");
    }

}

}

 

 

出处: http://www.blogjava.net/javadragon/archive/2006/12/03/85115.html