aop注解 事例

spring.xml中aop的配置

  <!-- 
         aop的配置
      -->
      <aop:config>
          <!-- 
               切入点表达式
           -->
          <aop:pointcut expression="execution(* cn.itcast.spring.aop.sh.PersonDaoImpl.*(..))" id="perform"/>
          <aop:aspect ref="myTransaction">
          <!-- 
              <aop:before method="beginTransaction" pointcut-ref="perform"/>
              <aop:after-returning method="commit" pointcut-ref="perform" returning="var"/>
           -->
              <aop:after method="finallyMethod" pointcut-ref="perform"/>
              <aop:after-throwing method="throwingMethod" pointcut-ref="perform" throwing="ex"/>
              <aop:around method="aroundMethod" pointcut-ref="perform"/>
          </aop:aspect>
      </aop:config>

 自定义的切面

注解形式的aop 写着 切面上

package cn.itcast.spring.aop.annotation.sh;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
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.hibernate.Transaction;
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("myTransaction")
@Aspect
public class MyTransaction extends HibernateUtils{
    private Transaction transaction;
    
    @Pointcut("execution(* cn.itcast.spring.aop.annotation.sh.PersonDaoImpl.*(..))")
    private void aa(){}//方法签名  返回值必须是void  方法的修饰符最好是private ，aa是随便定义的 做类比
    
    @Before("aa()")
    public void beginTransaction(JoinPoint joinpoint){
        this.transaction = sessionFactory.getCurrentSession().beginTransaction();
    }
    
    @AfterReturning(value="aa()",returning="val")
    public void commit(Object val){
        this.transaction.commit();
    }
    
}

 然后在spring.xml中引入

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
                         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
                         http://www.springframework.org/schema/context
                         http://www.springframework.org/schema/context/spring-context-3.0.xsd
                         http://www.springframework.org/schema/tx
                         http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
                         http://www.springframework.org/schema/aop 
                         http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">


<!--      扫描注解bean -->
     <context:component-scan base-package="cn.us.aspect"/>
<!--      开启切面代理 使得spring认识 @Aspect -->
     <aop:aspectj-autoproxy/>