Spring课程 Spring入门篇 5-4 advice应用（上）

课程链接：

1　　　　解析

1.1　　通知执行顺序

2　　　　代码演练

1　　　　解析

1.1　　通知执行顺序

aop执行方式为:前置通知==>所要增强的方法==>后置通知==>最终通知

在出现异常时会进行:前置通知==>所要增强的方法==>异常通知==>最终通知

而用xml进行配置时,是按照我们写好的顺序进行动态组合完成,最终和后置通知是随着xml配置的前后顺序改变的,但是经过测试不会影响前置和所要增强的方法的顺序,但是会影响最终和后置通知的位置.

我认为利用环绕通知进行方法的增强(aop:around)是一个比较好的方式,不会出现顺序问题.

2　　　　代码演练

2.1　　前置通知和后置通知

业务类：

package com.imooc.aop.schema.advice.biz;

public class AspectBiz {

    public void biz(){
        System.out.println("MoocAspect biz");
    }

    public void biz2(){
        System.out.println("MoocAspect biz2");
    }

}

配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<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-4.0.xsd">

<bean id = "moocAspect" class = "com.imooc.aop.schema.advice.MoocAspect"></bean>
<bean id = "AspectBiz" class = "com.imooc.aop.schema.advice.biz.AspectBiz"></bean>

<aop:config>
    <aop:aspect  id="moocAspectAOP" ref="moocAspect">
<!--     声明切入点：从哪里开始执行 -->
<!--     执行com.imooc.aop.schema.advice.biz包下的所有Biz结尾的java类中的所有方法时 -->
        <aop:pointcut expression="execution(* com.imooc.aop.schema.advice.biz.*Biz.*(..))" id="moocPointCut"/>
        <aop:before method="before" pointcut-ref="moocPointCut"/>
        <aop:after-returning method="after" pointcut-ref="moocPointCut"/>
    </aop:aspect>
</aop:config>

</beans>

通知（名词）所在的类：

package com.imooc.aop.schema.advice;

public class MoocAspect {

    public void before(){
        System.out.println("before");
    }

    public void after(){
        System.out.println("after");
    }

}

测试类：

package com.imooc.test.aop;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.BlockJUnit4ClassRunner;

import com.imooc.aop.schema.advice.biz.AspectBiz;
import com.imooc.test.base.UnitTestBase;

@RunWith(BlockJUnit4ClassRunner.class)
public class TestAOPSchemaAdvice extends UnitTestBase {

    public TestAOPSchemaAdvice(){
        super("classpath:spring-aop-schema-advice.xml");
    }

    @Test
    public void testBiz(){
        AspectBiz aBiz = super.getbean("AspectBiz");
        aBiz.biz();
        aBiz.biz2();
    }

}

打印结果：

四月 15, 2019 8:19:44 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@285855bd: startup date [Mon Apr 15 20:19:44 CST 2019]; root of context hierarchy
四月 15, 2019 8:19:44 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring-aop-schema-advice.xml]
before
MoocAspect biz
after
before
MoocAspect biz2
after
四月 15, 2019 8:19:45 下午 org.springframework.context.support.ClassPathXmlApplicationContext doClose
信息: Closing org.springframework.context.support.ClassPathXmlApplicationContext@285855bd: startup date [Mon Apr 15 20:19:44 CST 2019]; root of context hierarchy

 2.2　　异常通知和最终通知

业务类：

package com.imooc.aop.schema.advice.biz;

public class AspectBiz {

    public void biz(){
        System.out.println("MoocAspect biz");
        throw new RuntimeException();
    }

}

配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<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-4.0.xsd">

<bean id = "moocAspect" class = "com.imooc.aop.schema.advice.MoocAspect"></bean>
<bean id = "AspectBiz" class = "com.imooc.aop.schema.advice.biz.AspectBiz"></bean>

<aop:config>
    <aop:aspect  id="moocAspectAOP" ref="moocAspect">
<!--     声明切入点：从哪里开始执行 -->
<!--     执行com.imooc.aop.schema.advice.biz包下的所有Biz结尾的java类中的所有方法时 -->
        <aop:pointcut expression="execution(* com.imooc.aop.schema.advice.biz.*Biz.*(..))" id="moocPointCut"/>
        <aop:before method="before" pointcut-ref="moocPointCut"/>
        <aop:after-returning method="afterreturning" pointcut-ref="moocPointCut"/>
        <aop:after-throwing method="throwing" pointcut-ref="moocPointCut"/>
        <aop:after method="after" pointcut-ref="moocPointCut"/>

    </aop:aspect>
</aop:config>

</beans>

通知所在类：

package com.imooc.aop.schema.advice;

public class MoocAspect {

    public void before(){
        System.out.println("before");
    }

    public void afterreturning(){
        System.out.println("after returning");
    }

    public void throwing(){
        System.out.println("throw");
    }

    public void after(){
        System.out.println("Say Love me");
    }
}

测试类：

package com.imooc.test.aop;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.BlockJUnit4ClassRunner;

import com.imooc.aop.schema.advice.biz.AspectBiz;
import com.imooc.test.base.UnitTestBase;

@RunWith(BlockJUnit4ClassRunner.class)
public class TestAOPSchemaAdvice extends UnitTestBase {

    public TestAOPSchemaAdvice(){
        super("classpath:spring-aop-schema-advice.xml");
    }

    @Test
    public void testBiz(){
        AspectBiz aBiz = super.getbean("AspectBiz");
        aBiz.biz();
    }

}

打印日志：

四月 16, 2019 7:18:45 上午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@4b19b8ae: startup date [Tue Apr 16 07:18:45 CST 2019]; root of context hierarchy
四月 16, 2019 7:18:45 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring-aop-schema-advice.xml]
before
MoocAspect biz
throw
Say Love me
四月 16, 2019 7:18:46 上午 org.springframework.context.support.ClassPathXmlApplicationContext doClose
信息: Closing org.springframework.context.support.ClassPathXmlApplicationContext@4b19b8ae: startup date [Tue Apr 16 07:18:45 CST 2019]; root of context hierarchy