问题 ： lang.NoClassDefFoundError: org/springframework/core/annotation/AnnotatedElementUtils，的解决方法

今天在做junit 测试的时候  出现了一个问题，花了一段时间 才解决。

java.lang.NoClassDefFoundError: org/springframework/core/annotation/AnnotatedElementUtils
at org.springframework.test.util.MetaAnnotationUtils$AnnotationDescriptor.<init>(MetaAnnotationUtils.java:289)
at org.springframework.test.util.MetaAnnotationUtils$UntypedAnnotationDescriptor.<init>(MetaAnnotationUtils.java:349)
at org.springframework.test.util.MetaAnnotationUtils$UntypedAnnotationDescriptor.<init>(MetaAnnotationUtils.java:344)
at org.springframework.test.util.MetaAnnotationUtils.findAnnotationDescriptorForTypes(MetaAnnotationUtils.java:191)
at org.springframework.test.util.MetaAnnotationUtils.findAnnotationDescriptorForTypes(MetaAnnotationUtils.java:166)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:271)
at org.springframework.test.context.DefaultTestContext.<init>(DefaultTestContext.java:67)
at org.springframework.test.context.TestContextManager.<init>(TestContextManager.java:103)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTestContextManager(SpringJUnit4ClassRunner.java:124)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.<init>(SpringJUnit4ClassRunner.java:115)
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.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:31)
at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:24)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:29)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:24)
at org.junit.internal.requests.FilterRequest.getRunner(FilterRequest.java:33)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
Caused by: java.lang.ClassNotFoundException: org.springframework.core.annotation.AnnotatedElementUtils
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)
... 24 more

这个问题是  因为找不到 springframework 的 一个类  AnnotatedElementUtils， 这个类 是因为 没有引入的pom  中，所以在编译的时候找不到，方法很简单，只需要在pom 文件中引入就可以了

<properties>
    <spring.version>4.1.1.RELEASE</spring.version>
</properties>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>${spring.version}</version>
</dependency>

这个依赖添加进去之后就解决问题了。

还有，在项目的lib  目录里面的  jar 包， 在试用mvn install的时候会报错 ，需要把这个jar  包传到  maven的 资源库，然后 在pom  中 添加依赖，这样才可以成功编译