Spring和Vaadin - ClassNotFoundException: ClassNotFoundException

Question

我在start.spring.io上生成了Spring项目，它只具有Vaadin依赖项(Maven项目，SpringBoot1.5.1，Vaadin依赖项)。

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我已经解压缩了加载的.zip文件，并将项目导入到STS (文件-> imported ->现有Maven项目)。我试图运行这个应用程序，但是我得到了一个例外：

Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/web/context/support/WebApplicationObjectSupport
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
at java.lang.Class.getDeclaredMethods(Class.java:1975)
at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:613)
at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:524)
at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:510)
at org.springframework.util.ReflectionUtils.getUniqueDeclaredMethods(ReflectionUtils.java:570)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getTypeForFactoryMethod(AbstractAutowireCapableBeanFactory.java:697)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:640)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:609)
at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1484)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:425)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:395)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:515)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:508)
at org.springframework.context.support.AbstractApplicationContext.getBeansOfType(AbstractApplicationContext.java:1189)
at org.springframework.boot.SpringApplication.getExitCodeFromMappedException(SpringApplication.java:862)
at org.springframework.boot.SpringApplication.getExitCodeFromException(SpringApplication.java:848)
at org.springframework.boot.SpringApplication.handleExitCode(SpringApplication.java:834)
at org.springframework.boot.SpringApplication.handleRunFailure(SpringApplication.java:788)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:325)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1162)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1151)
at com.example.MyvaadinApplication.main(MyvaadinApplication.java:10)

Caused by: java.lang.ClassNotFoundException: org.springframework.web.context.support.WebApplicationObjectSupport
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)
... 60 more

该项目可以在跳过测试时由Maven (干净安装)构建。在启用测试的情况下，同样的错误会导致失败。

我已经试过了：

• 导入项目并在不同的Idea中运行它(STS、Eclipse、Idea)
• 从测试类以Spring、Java应用程序的身份运行应用程序
• Spring的其他版本(1.5.1，1.4.4)
• 不同的Java 8 (jdk1.8.0_65，jdk1.8.0_121)
• 重启IDE

Answer 1

基于p.streef的评论，我找到了解决方案。我清除了Maven存储库(更准确地说，我删除了Spring文件所在的.m2\repository\org\springframework文件夹的内容)，并再次运行应用程序。然后起作用了。

编辑

这似乎是常见的问题。最近，我尝试使用Vaadin、JPA和H2依赖项创建一个新的Spring项目。一开始我得到：

spring boot Error creating bean with name 'entityManagerFactory'

我删除了.m2\repository\org\hibernate中的jars并运行mvn干净安装，得到：

spring boot NoClassDefFoundError: javassist/bytecode/ClassFile

我删除了.m2\repository\org\javassist中的jars并运行mvn干净安装

现在起作用了。因此，当您在运行新创建的Spring项目时遇到一些错误时，在存储库中清除某个类，然后再试一次。