spring AOP四种实现方式

1. 经典的基于代理的AOP 

  1. 创建通知:定义一个接口

 

public interface Sleepable{
 
    void sleep(); 
}
然后写一个Human类,他实现了这个接口


public Human implements Sleepable{
   
   public void sleep(){
      System.out.println("睡觉中...!");
   }

}

2.编写一个SleepHelper类,它里面包含了睡觉的辅助工作,用AOP术语来说它就应该是通知

public class SleepHelper implements MethodBeforeAdvice,AfterReturningAdvice  {

    public void before(Method method, Object[] arguments, Object target)
            throws Throwable {
        System.out.println("睡觉前");
        
    }

    public void afterReturning(Object rturnValue, Method method, Object[] arguments,
            Object target) throws Throwable {
        System.out.println("睡觉后");
        
    }

}

然后在spring配置文件中进行配置:

<!-- 被代理目标对象 -->

<bean id="Human" class="cn.happy.dao.Human"></bean>

<bean id="SleepHelper" class="cn.happy.aop.SleepHelper"></bean>
//定义切点的常用的两种方式:1)使用正则表达式 2)使用AspectJ表达式,
//这里用正则表达式

<!-- 顾问 -->
     <bean id="BeforAdvisor" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
      
        <property name="advice" ref="BeforAdvice"></property>
       <property name="pattern" value=".*l.*g.*"></property>
       </bean>


<!-- 代理对象 -->
// ProxyFactoryBean是一个代理,我们可以把它转换为
//proxyInterfaces中指定的实现该interface的代理对象
      <bean id="serviceProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
      
        <property name="target" ref="Human"></property>
       <property name="interceptorNames" value="BeforAdvisor"></property>
       </bean>

代理类

public class StuTest {
    public static void main(String[] args) {
        //通过ClassPathXmlApplicationContext实例化Spring的上下文
        ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
        //通过ApplicationContext的getBean()方法,根据id来获取Bean的实例
        Sleepable s=(Sleepable)context.getBean("Human");
        s.sleep();
    }
}

3、使用AspectJ的注解

用@Aspect的注解来标识切面

@Aspect//该类为切面
public class MyAspect {
    @Before(value="execution(public * *(..))")
 public void mybefore(){
     
         System.out.println("前置增强");
 }
    //后置增强
    @AfterReturning(value="execution(public * *(..))")
     public void myafterReturning(){
         
             System.out.println("后置增强");
     }
    
    //异常增强
        @AfterThrowing(value="execution(public * *(..))")
         public void myafterThrowing(){
             
                 System.out.println("异常增强");
         }
        
        //环绕增强
        @Around(value="execution(public * *(..))")
         public void myAround(ProceedingJoinPoint jp){
            System.out.println("环绕前增强");
                 try {
                    jp.proceed();
                } catch (Throwable e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                 System.out.println("环绕后增强");
                 
         }
        
        //最终增强
                @After(value="execution(public * *(..))")
                 public void myafterLogger(){
                     
                         System.out.println("最终增强");
                 }
}

Spring配置文件:

<!-- 目标对象 -->
   <bean id="Human" class="cn.happy.dao.IserviceImpl"></bean>

   <!-- 切面: -->
   <bean id="myAspect" class="cn.happy.aop.MyAspect"></bean>
   
  <aop:aspectj-autoproxy/>

测试类

public class StuTest {
    public static void main(String[] args) {
        ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
        Sleepable s=(Sleepable)context.getBean("Service");
        s.sleep();
    }
}

4、通过<aop:config>来配置(纯POJO切面)

<aop:advisor> 定义一个AOP通知者
<aop:after> 后通知
<aop:after-returning> 返回后通知
<aop:after-throwing> 抛出后通知
<aop:around> 周围通知
<aop:aspect>定义一个切面
<aop:before>前通知
<aop:config>顶级配置元素,类似于<beans>这种东西
<aop:pointcut>定义一个切点

public class MyAspect {
 public void mybefore(){
     
         System.out.println("前置增强");
 }
 public String myafterReturning(String Returning){
     
         System.out.println("前置增强");
        return Returning;
}
}
public class IserviceImpl implements Iservice{

    public void log() {
        System.out.println("开启事务");
        
    }

    public String dofirst() {
        System.out.println("记录日志");
        return "";
        
    }

    
}

Spring的配置文件:

<!-- 目标对象 -->
   <bean id="Service" class="cn.happy.dao.IserviceImpl"></bean>

   <!-- 切面: -->
   <bean id="myAspect" class="cn.happy.aop.MyAspect"></bean>
   <!-- 配置切面 -->
   <aop:config>
   <!-- 配置切入点 -->
       <aop:pointcut id="pointcut" expression="execution(public * *..Iservice.log(..))"/>
       <!-- 将类方法定义为最终增强并引用pointcut切入点-->
       <aop:aspect ref="myAspect">
           <aop:after method="myafterReturning" pointcut-ref="pointcut"/>
       </aop:aspect>
   </aop:config>

测试类

public class SpringTest {
    public static void main(String[] args) {
         ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
         Iservice bean = (Iservice)context.getBean("Service");
        bean.log();
        String count=bean.dofirst();
         System.out.println(count);
    }
}

 

posted @ 2016-10-13 10:12  菜鸟诶!  阅读(9253)  评论(0编辑  收藏  举报