一个使用Spring的AspectJ LTW的简单例子

参考：Spring Framework Reference Documentation

AspectJ是实现AOP编程的一种具体实现

AspectJ中有两种实现的方式：

1.使用Ajc编译器在编译器生成代理类

2.使用AspectJ LTW 在类加载时生成代理

主要的Bean

public class DemoBean {

        public void run() {

            System.out.println("Run");

        }

        public void run1() {

            System.out.println("run1...");

        }

        public void run2() throws Exception {

            TimeUnit.SECONDS.sleep(2);

            System.out.println("run2...");

        }

    }

Aspect

import org.aspectj.lang.ProceedingJoinPoint;

import org.aspectj.lang.annotation.Around;

import org.aspectj.lang.annotation.Aspect;

import org.aspectj.lang.annotation.Pointcut;

import org.springframework.util.StopWatch;

@Aspect

public class ProfilingAspect {

    @Around("profileMethod()")

    public Object profile(ProceedingJoinPoint pjp) throws Throwable {

        StopWatch sw = new StopWatch(getClass().getSimpleName());

        try {

            sw.start(pjp.getSignature().getName());

            return pjp.proceed();

        } finally {

            sw.stop();

            System.out.println(sw.prettyPrint());

        }

    }

    @Pointcut("execution(* com.jxufe.study.spring.aspect..*.*(..))")

    public void profileMethod() {

    }

}

META-INF/aop.xml （这个路径和名字是确定的）

<!DOCTYPE aspectj PUBLIC "-//AspectJ//DTD//EN" "http://www.eclipse.org/aspectj/dtd/aspectj.dtd">

    <aspectj>

        <weaver>

            <!-- only weave classes in our application-specific packages -->

            <include within="com.jxufe.study.spring.aspect.*"/>

        </weaver>

        <aspects>

            <!-- weave in just this aspect -->

            <aspect name="com.jxufe.study.spring.aspect.ProfilingAspect"/>

        </aspects>

    </aspectj>

最后的aspect.xml

<?xml version="1.0" encoding="GBK"?>

<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"

       xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"

       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

        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd

        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

    <context:load-time-weaver/>

   <bean id="demoBean" class="com.jxufe.study.spring.aspect.DemoBean"></bean>

</beans>

Test类

 public static void main(String[] args) throws Exception {

        ApplicationContext ctx = new ClassPathXmlApplicationContext("/META-INF/aspect.xml", Main.class);

/*

        DemoBean demoBean = (DemoBean) ctx.getBean("de");

*/

        DemoBean demoBean  = new DemoBean();

        demoBean.run();

        demoBean.run1();

        demoBean.run2();

运行时添加 jvm 参数 -javaagent:C:\Users\1\.m2\repository\org\springframework\spring-instrument\4.3.9.RELEASE\spring-instrument-4.3.9.RELEASE.jar

输出结果：

Run

StopWatch 'ProfilingAspect': running time (millis) = 0

-----------------------------------------

ms     %     Task name

-----------------------------------------

00000  �  run

run1...

StopWatch 'ProfilingAspect': running time (millis) = 1

-----------------------------------------

ms     %     Task name

-----------------------------------------

00001  100%  run1

Disconnected from the target VM, address: '127.0.0.1:52489', transport: 'socket'

run2...

StopWatch 'ProfilingAspect': running time (millis) = 2003

-----------------------------------------

ms     %     Task name

-----------------------------------------

02003  100%  run2

这里的Test类中，这个Bean中使用的是DemoBean demoBean = new DemoBean();但结果却是实现了AOP的效果。

巴特西

一个使用Spring的AspectJ LTW的简单例子

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