背景：学习切面，测试前置通知功能，xml配置如下

<?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:context="http://www.springframework.org/schema/context"
       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/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd" >

        <bean id="ikAspect" class="com.jing.spring.aop.IKAspect"></bean>
        <bean id="ikAspectBiz" class="com.jing.spring.aop.IKAspectBiz"></bean>

        <aop:config>
                <aop:aspect id="ikAspectAop" ref="ikAspect">
                        <aop:pointcut id="ikPoint" expression="execution(* com.jing.spring.aop.IKAspectBiz.*(..))"></aop:pointcut>
                        <aop:before method="aspectBefore" pointcut-ref="ikPoint"></aop:before>
                </aop:aspect>
        </aop:config>
</beans>

报错:org.aspectj.weaver.reflect.ReflectionWorld$ReflectionWorldException

Caused by: java.lang.NoClassDefFoundError: org/aspectj/weaver/reflect/ReflectionWorld$ReflectionWorldException
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671)
    at java.lang.Class.getConstructor0(Class.java:3075)
    at java.lang.Class.getDeclaredConstructor(Class.java:2178)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:80) ... 66 more Caused by: java.lang.ClassNotFoundException: org.aspectj.weaver.reflect.ReflectionWorld$ReflectionWorldException at java.net.URLClassLoader.findClass(URLClassLoader.java:381) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ... 71 more

原因:Spring AOP 虽然有自己的AOP功能，但是它是依赖AspectJ来实现的。使用maven搭建的项目pom.xml中，没有引入aspectjweaver包。

解决办法：在pom.xml中引入aspectjweaver包。

<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.2</version>
        </dependency>

测试成功

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