Spring AOP面向切面编程

1、1）Aspect(切面）

      比如说事务、权限等，与业务逻辑没有关系的部分

     2）joinPoint(连接点）

      目标类的目标方法。

     3）PointCut(切入点)

    就是指我们要对哪些方法拦截的定义

     4）Advice（通知）

     5）Target(目标对象）

  代理的目标对象

   6）Weaving(织入）

  是指把切面应用到目标对象来创建新的代理对象的过程，切面在指定的连接点织入到目标对象

2、通知（Advice)分为

Before ——前置通知

After——后置通知

After-returning——最后通知

After-throwing ——异常通知

Around——环绕通知

配置文件

<? xml version = "1.0" encoding = "UTF-8" ?>

< beans xmlns = "http://www.springframework.org/schema/beans"

     xmlns:aop = "http://www.springframework.org/schema/aop"

     xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"

     xsi:schemaLocation="http://www.springframework.org/schema/beans

            http://www.springframework.org/schema/beans/spring-beans-2.5.xsd

            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">

     <!--

         spring aop的命名空间需要自己加进来

         http://www.springframework.org/schema/beans/spring-beans-2.5.xsd

         http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd

         spring aop还需要两个jar包

         aspectjrt.jar

         aspectjweaver.jar

     

         导入目标类，导入切面

      -->      

     < bean id = "personDao" class = "_10SpringAOP.PersonDaoImpl" ></ bean >

     < bean id = "myTransaction" class = "_10SpringAOP.MyTransaction" ></ bean >

     < aop:config >

         < aop:pointcut expression = "execution(* _10SpringAOP.PersonDaoImpl.*(..))" id = "perform" />

         < aop:aspect ref = "myTransaction" >

             < aop:before method = "beginTransaction" pointcut-ref = "perform" />

             <!-- 记得加上returning -->

             < aop:after-returning method = "commit" pointcut-ref = "perform" returning = "var" />

             < aop:after method = "finalMethod" pointcut-ref = "perform" />

             <!-- 记得加上throwsing -->

             < aop:after-throwing method = "throwMethod" pointcut-ref = "perform" throwing = "ex" />

             < aop:around method = "aroundMethod" pointcut-ref = "perform" />

         </ aop:aspect >

     </ aop:config >

</ beans >

注解形式例子

import org.aspectj.lang.annotation.AfterReturning; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; import org.aspectj.lang.annotation.Pointcut; import org.springframework.stereotype.Component; /**   * @Aspect   * ==   * <aop:config>   *   <aop:pointcut   *      expression=   *     "execution(* cn.itcast.spring.aop.annotation.sh.PersonDaoImpl.*(..))"   *     id="aa()"/>   * </aop:config>   * @author Think   *   */ @Component ( "MyTranscation" ) @Aspect public class MyTranscation {      //说明那个是目标对象      @Pointcut ( "execution(* _13SpringAop_annotation.PersonDaoImpl.*(..))" )      //方法签名  返回值必须是void  方法的修饰符最好是private      //空方法      private void add(){}      @Before ( "add()" )      public void beginTransaction(){          System.out.println( "beginTranscation" );      }      @AfterReturning (value= "add()" ,returning= "var" )      public void commit(Object var){          System.out.println( "commit" );          System.out.println( "var is " + var);      } }

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package _13SpringAop_annotation; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; //beginTranscation //save person //commit //var is aaa public class test {      public static void main (String[] args){          ApplicationContext context =              new ClassPathXmlApplicationContext( "applicationContext.xml" );          PersonDaoImpl persondao = (PersonDaoImpl) context.getBean( "personDao" );          persondao.savePerson( new Person());      } }

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<? xml version = "1.0" encoding = "UTF-8" ?> < beans xmlns = "http://www.springframework.org/schema/beans"      xmlns:context = "http://www.springframework.org/schema/context"      xmlns:aop = "http://www.springframework.org/schema/aop"      xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"      xsi:schemaLocation="http://www.springframework.org/schema/beans             http://www.springframework.org/schema/beans/spring-beans-2.5.xsd             http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd             http://www.springframework.org/schema/context             http://www.springframework.org/schema/context/spring-context-2.5.xsd">     <!--          把目标类和切面纳入到spring容器中管理，启动类扫描的机制      -->      < context:component-scan base-package = "_13SpringAop_annotation" ></ context:component-scan >      <!--          启动aop的注解解析器       -->      < aop:aspectj-autoproxy ></ aop:aspectj-autoproxy > </ beans >