springAOP的第一个例子

同样是拿一个Person类和Transaction类来举例子

 

导入相关的jar包

Person.java

public interface PersonDao {
  public void savePerson();
}

public class PersonDaoImpl implements PersonDao {
  public void savePerson() {
    System.out.println("savePerson");
  }
}

Transaction.java

public class Transaction {
  public void beginTransaction(){
    System.out.println("beginTransaction");
  }
  public void commit(){
    System.out.println("commit");
  }
}

在applicationContext.xml的配置文件中，注意头文件的不同

<?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">
        
  <bean id="personDao" class="com.mo.transaction.PersonDaoImpl"></bean>   
  <bean id="transaction" class="com.mo.transaction.Transaction"></bean>
  
  <aop:config>
    <!-- 切入点表达式，确定目标类 -->
    <aop:pointcut 
      expression="execution(* com.mo.transaction.PersonDaoImpl.*(..))" 
      id="perform"/>
      
    <!-- ref指向的对象就是切面 -->
    <aop:aspect ref="transaction">
      <!-- 前置通知，指向切入点表达式 -->
      <aop:before method="beginTransaction" pointcut-ref="perform"/>
      <!-- 后置通知，指向切入点表达式 -->
      <aop:after method="commit" pointcut-ref="perform"/>
    </aop:aspect>
  </aop:config>
</beans>

测试单元

@Test
public void  aopTest(){
  ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");  
  PersonDao personDao = (PersonDao)context.getBean("personDao");
  personDao.savePerson();
}

测试的结果

beginTransaction

savePerson

commit