java.lang.NoClassDefFoundError: org/aopalliance/intercept/MethodInterceptor

错误信息

今天在学习AOP的时候碰上了以下错误。

org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘org.springframework.aop.config.internalAutoProxyCreator’: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/aopalliance/intercept/MethodInterceptor

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1076)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1021)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)

at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)

at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)

at org.springframework.context.support.PostProcessorRegistrationDelegate.registerBeanPostProcessors(PostProcessorRegistrationDelegate.java:220)

at org.springframework.context.support.AbstractApplicationContext.registerBeanPostProcessors(AbstractApplicationContext.java:618)

at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:467)

at org.springframework.context.support.ClassPathXmlApplicationContext.(ClassPathXmlApplicationContext.java:139)

at org.springframework.context.support.ClassPathXmlApplicationContext.(ClassPathXmlApplicationContext.java:83)

at com.zz.test.AOP_Test.test(AOP_Test.java:16)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:606)

at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)

at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)

at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)

at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)

at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)

at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)

at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)

at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)

at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)

at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)

at org.junit.runners.ParentRunner.run(ParentRunner.java:236)

at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)

at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/aopalliance/intercept/MethodInterceptor

at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:164)

at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1069)

… 36 more

Caused by: java.lang.NoClassDefFoundError: org/aopalliance/intercept/MethodInterceptor

at org.springframework.aop.framework.adapter.DefaultAdvisorAdapterRegistry.(DefaultAdvisorAdapterRegistry.java:50)

at org.springframework.aop.framework.adapter.GlobalAdvisorAdapterRegistry.(GlobalAdvisorAdapterRegistry.java:32)

at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.(AbstractAutoProxyCreator.java:122)

at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.(AbstractAdvisorAutoProxyCreator.java:48)

at org.springframework.aop.aspectj.autoproxy.AspectJAwareAdvisorAutoProxyCreator.(AspectJAwareAdvisorAutoProxyCreator.java:47)

at org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator.(AnnotationAwareAspectJAutoProxyCreator.java:49)

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

at java.lang.reflect.Constructor.newInstance(Constructor.java:526)

at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:148)

… 38 more

Caused by: java.lang.ClassNotFoundException: org.aopalliance.intercept.MethodInterceptor

at java.net.URLClassLoader$1.run(URLClassLoader.java:366)

at java.net.URLClassLoader$1.run(URLClassLoader.java:355)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:354)

at java.lang.ClassLoader.loadClass(ClassLoader.java:425)

at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)

at java.lang.ClassLoader.loadClass(ClassLoader.java:358)

… 49 more

当时的环境

1、Spring4.0.4的21个RELEASE结尾jar包

2、commons-logging-1.2.jar

3、aspectjrt.jar、aspectjweaver.jar

beans_aop.xml

[code]<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
                        http://www.springframework.org/schema/beans/spring-beans-4.0.xsd                         http://www.springframework.org/schema/context                         http://www.springframework.org/schema/context/spring-context-4.0.xsd                         http://www.springframework.org/schema/aop                         http://www.springframework.org/schema/aop/spring-aop-4.0.xsd">     <!-- 自动扫描指定包及其子包下的所有Bean类 -->
    <context:component-scan 
        base-package="com.zz.aop" />
    <!-- 注解实现AOP -->
    <aop:aspectj-autoproxy />
</beans>

com.zz.aop.Person.java

[code]@Component
public class Person {
    public void go() {
        System.out.println("出发");
    }
}

com.zz.aop.LogInterceptor.java

[code]@Aspect
@Component
public class LogInterceptor {
    @Before("execution(public void com.zz.aop.Person.go())")
    public void before() {
        System.out.println("method start");
    }
}

JUnit测试单元（和写在main里一样）

[code]public class AOP_Test {
    @Test
    public void test() {
        ApplicationContext ctx = 
                new ClassPathXmlApplicationContext("beans_aop.xml");
            // 获取Spring容器中所有的Bean实例的名称
            Person person = ctx.getBean("person", Person.class);
            person.go();
    }
}

分析

首先关注到报错信息的第一行：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘org.springframework.aop.config.internalAutoProxyCreator’: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/aopalliance/intercept/MethodInterceptor

大概意思是在创建哪个类时出了什么什么错，关键是最后这个“java.lang.NoClassDefFoundError”，也就是找不到这个类：org/aopalliance/intercept/MethodInterceptor。

首先，我试着把“MethodInterceptor”复制到MyEclipse的java文件里，用alt+/自动提示一下，发现只有一个org.springframework.cglib.proxy.MethodInterceptor这样的类，那十有八九是缺jar包了。
然后，用“org/aopalliance/intercept/MethodInterceptor”作为关键字去搜索，发现这个类是在“aopalliance.jar”里。
最后，下载aopalliance.jar并将其配置到环境里，问题解决，能正常运行了。

解决方案

在Build Path里导入aopalliance.jar

（该jar包以上传到我的资源）