11Spring - 基于AspectJ的AOP开发（注解的方式）

Spring 使用 AspectJ 进行 AOP 的开发

​1）引入相关的jar包​

• ​spring 的传统 AOP 的开发的包： spring-aop-4.2.4.RELEASE.jar
  com.springsource.org.aopalliance-1.0.0.jar
• ​aspectJ 的开发包: com.springsource.org.aspectj.weaver-1.6.8.RELEASE.jar
  spring-aspects-4.2.4.RELEASE.jar
  

​2）引入Spring的配置文件​

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

​3）编写目标类​

public class ProductDao {
    public void save() {
        System.out.println("保存商品...");
    }

    public void update() {
        System.out.println("修改商品...");
    }

    public void delete() {
        System.out.println("删除商品...");
    }

    public void find() {
        System.out.println("查询商品...");
    }
}

​4）配置目标类​

<bean id="productDao" class="cn.itcast.spring.demo4.ProductDao"></bean>

​5）开启aop注解的自动代理​

<aop:aspectj-autoproxy/>

​6）AspectJ的AOP的注解​

@Aspect:定义切面类的注解

通知类型:

• @Before :前置通知
• @AfterReturing :后置通知
• @Around :环绕通知
• @After :最终通知
• @AfterThrowing :异常抛出通知.
• @Pointcut:定义切入点的注解

​7）编写切面类​

@Aspect
public class MyAspectAnno {
    
    @Before("MyAspectAnno.pointcut1()")
    public void before() {
        System.out.println("前置通知===========");
    }

    @Pointcut("execution(* cn.itcast.spring.demo4.ProductDao.save(..))")
    private void pointcut1() {
    }
}

​8）配置切面​

<!-- 配置切面类 -->
<bean id="myAspectAnno" class="cn.itcast.spring.demo4.MyAspectAnno"></bean>

​9）其它通知的注解​

@Aspect
public class MyAspectAnno {
    @Before("MyAspectAnno.pointcut1()")
    public void before() {
        System.out.println("前置通知===========");
    }

    @AfterReturning("MyAspectAnno.pointcut2()")
    public void afterReturning() {
        System.out.println("后置通知===========");
    }

    @Around("MyAspectAnno.pointcut3()")
    public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
        System.out.println("环绕前通知==========");
        Object obj = joinPoint.proceed();
        System.out.println("环绕后通知==========");
        return obj;
    }

    @AfterThrowing("MyAspectAnno.pointcut4()")
    public void afterThrowing() {
        System.out.println("异常抛出通知========");
    }

    @After("MyAspectAnno.pointcut4()")
    public void after() {
        System.out.println("最终通知==========");
    }

    @Pointcut("execution(* cn.itcast.spring.demo4.ProductDao.save(..))")
    private void pointcut1() {
    }

    @Pointcut("execution(* cn.itcast.spring.demo4.ProductDao.update(..))")
    private void pointcut2() {
    }

    @Pointcut("execution(* cn.itcast.spring.demo4.ProductDao.delete(..))")
    private void pointcut3() {
    }

    @Pointcut("execution(* cn.itcast.spring.demo4.ProductDao.find(..))")
    private void pointcut4() {
    }
}