Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/web/socket/server/standard/ServerEndpointExporter
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:1188)
at org.springframework.boot.SpringApplication.getExitCodeFromMappedException(SpringApplication.java:818)
at org.springframework.boot.SpringApplication.getExitCodeFromException(SpringApplication.java:804)
at org.springframework.boot.SpringApplication.handleExitCode(SpringApplication.java:790)
at org.springframework.boot.SpringApplication.handleRunFailure(SpringApplication.java:744)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:314)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)
at com.ros.RosApplication.main(RosApplication.java:19)
Caused by: java.lang.ClassNotFoundException: org.springframework.web.socket.server.standard.ServerEndpointExporter
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 24 more

是因為我在包的引用過程中加入了在編譯時才使用這個類

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-websocket</artifactId>
   <scope>provided</scope>
</dependency>

Caused by: java.lang.ClassNotFoundException: org.springframework.web.socket.server.standard.ServerEndpointExporter