Spring AOP功能的实现

主要有两种方式：一种是基于XML Schema的设置，一种是基于Annotation的支持

基于XML Schema的前置通知（现在LogBeforeAdvice不需要实现MethodBeforeAdvice）

public class LogBeforeAdvice {
    public void before(JoinPoint joinPoint) {
        System.out.println(joinPoint.getSignature().getName()+",start.............LogBeforeAdvice");
    }
}

<bean id="logBeforeAdvice" class="com.edu.cug.LogBeforeAdvice"></bean>
    <aop:config>
        <aop:aspect id="logBeforeAspect" ref="logBeforeAdvice">
            <aop:pointcut id="LogbeforePointcut" expression="execution(* hello*(..))"/>
            <aop:before pointcut-ref="LogbeforePointcut" method="before"/>
        </aop:aspect>
    </aop:config>

测试程序:

public class AopTest {

    public static void main(String[] args) {
        BeanFactory factory = new ClassPathXmlApplicationContext(
                "applicationContext.xml");
        IHello bean = (IHello) factory.getBean("IHello");
        bean.hello1("AOP1");
        bean.hello2("AOP2");
    }
}

测试结果

hello1,start.............LogBeforeAdvice
hello1,AOP1
hello2,start.............LogBeforeAdvice
hello2,AOP2

• 基于Annotation的前置通知
• 定义切面：

  @Aspect
  public class LogBeforeAdvice {
      
      @Pointcut("execution(* com.edu.cug.IHello.*(..)) ")
      public void anymethod(){} 
      
      @Before("anymethod()")
      public void before(JoinPoint joinPoint) {
          System.out.println(joinPoint.getSignature().getName()
                  + ",start.............LogBeforeAdvice");
      }
  }

  <bean id="IHello" class="com.edu.cug.IHelloImpl"></bean>
      <bean id="logBeforeAdvice" class="com.edu.cug.LogBeforeAdvice"></bean>
      <aop:aspectj-autoproxy/>

  测试程序

  public class AopTest {
      public static void main(String[] args) {
          BeanFactory factory = new ClassPathXmlApplicationContext(
                  "applicationContext.xml");
          IHello bean = (IHello) factory.getBean("IHello");
          bean.hello1("AOP1");
          bean.hello2("AOP2");
      }
  }

  测试结果

  hello1,start.............LogBeforeAdvice
  hello1,AOP1
  hello2,start.............LogBeforeAdvice
  hello2,AOP2

  在Spring2.x中要声明Pointcut，主要包括两个部分：Pointcut表达式(expression)与Pointcut签名(signature)