java.lang.ClassNotFoundException: com.fasterxml.jackson.databind.exc.InvalidDefinitionException
java.lang.ClassNotFoundException: com.fasterxml.jackson.databind.exc.InvalidDefinitionException
所以我正在尝试使用动态 Web 项目创建一个 Spring MVC 项目，并且我正在尝试使用一个 Employee class 作为数据库中的项目。但是，我遇到了一个问题，它抱怨我的 class 没有 return 值，尽管有吸气剂。我了解到我必须将 jackson-core 和 jackson-databind 添加到我的项目中才能使其正常工作。但是，当我这样做时，出现以下异常：
Type Exception Report
Message Servlet.init() for servlet [dispatcher] threw exception
Description The server encountered an unexpected condition that prevented it from fulfilling the request.
Exception
javax.servlet.ServletException: Servlet.init() for servlet [dispatcher] threw exception
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
Root Cause
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/exc/InvalidDefinitionException
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1232)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1131)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=12=](AbstractBeanFactory.java:312)
org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda/1293185169.getObject(Unknown Source)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:676)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:642)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:690)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:558)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:499)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:172)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
Root Cause
org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/exc/InvalidDefinitionException
org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:175)
org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1224)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1131)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=12=](AbstractBeanFactory.java:312)
org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda/1293185169.getObject(Unknown Source)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:676)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:642)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:690)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:558)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:499)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:172)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
Root Cause
java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/exc/InvalidDefinitionException
org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter.<init>(AllEncompassingFormHttpMessageConverter.java:74)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.<init>(RequestMappingHandlerAdapter.java:190)
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
java.lang.reflect.Constructor.newInstance(Unknown Source)
org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163)
org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1224)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1131)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=12=](AbstractBeanFactory.java:312)
org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda/1293185169.getObject(Unknown Source)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:676)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:642)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:690)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:558)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:499)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:172)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
Root Cause
java.lang.ClassNotFoundException: com.fasterxml.jackson.databind.exc.InvalidDefinitionException
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1415)
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1223)
org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter.<init>(AllEncompassingFormHttpMessageConverter.java:74)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.<init>(RequestMappingHandlerAdapter.java:190)
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
java.lang.reflect.Constructor.newInstance(Unknown Source)
org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163)
org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1224)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1131)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=12=](AbstractBeanFactory.java:312)
org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda/1293185169.getObject(Unknown Source)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:676)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:642)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:690)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:558)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:499)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:172)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
Note The full stack trace of the root cause is available in the server logs.
当我没有 jackson 文件（并且不调用 Employee class）时，不会出现异常。我错过了什么吗？
提前致谢！
检查您使用的是哪个版本的 jackson-databind。
根据该主题：
如果您使用的是 Spring 5.0.2，则支持的 Jackson 版本是 2.9.2。尽管如此，您绝对应该努力创建一个 Maven 项目。在 IDE 中手动管理依赖项是自找麻烦。
所以我正在尝试使用动态 Web 项目创建一个 Spring MVC 项目，并且我正在尝试使用一个 Employee class 作为数据库中的项目。但是，我遇到了一个问题，它抱怨我的 class 没有 return 值，尽管有吸气剂。我了解到我必须将 jackson-core 和 jackson-databind 添加到我的项目中才能使其正常工作。但是，当我这样做时，出现以下异常：
Type Exception Report
Message Servlet.init() for servlet [dispatcher] threw exception
Description The server encountered an unexpected condition that prevented it from fulfilling the request.
Exception
javax.servlet.ServletException: Servlet.init() for servlet [dispatcher] threw exception
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
Root Cause
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/exc/InvalidDefinitionException
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1232)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1131)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=12=](AbstractBeanFactory.java:312)
org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda/1293185169.getObject(Unknown Source)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:676)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:642)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:690)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:558)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:499)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:172)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
Root Cause
org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/exc/InvalidDefinitionException
org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:175)
org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1224)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1131)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=12=](AbstractBeanFactory.java:312)
org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda/1293185169.getObject(Unknown Source)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:676)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:642)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:690)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:558)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:499)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:172)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
Root Cause
java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/exc/InvalidDefinitionException
org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter.<init>(AllEncompassingFormHttpMessageConverter.java:74)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.<init>(RequestMappingHandlerAdapter.java:190)
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
java.lang.reflect.Constructor.newInstance(Unknown Source)
org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163)
org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1224)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1131)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=12=](AbstractBeanFactory.java:312)
org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda/1293185169.getObject(Unknown Source)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:676)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:642)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:690)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:558)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:499)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:172)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
Root Cause
java.lang.ClassNotFoundException: com.fasterxml.jackson.databind.exc.InvalidDefinitionException
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1415)
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1223)
org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter.<init>(AllEncompassingFormHttpMessageConverter.java:74)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.<init>(RequestMappingHandlerAdapter.java:190)
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
java.lang.reflect.Constructor.newInstance(Unknown Source)
org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163)
org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1224)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1131)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=12=](AbstractBeanFactory.java:312)
org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda/1293185169.getObject(Unknown Source)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:676)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:642)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:690)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:558)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:499)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:172)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
Note The full stack trace of the root cause is available in the server logs.
当我没有 jackson 文件（并且不调用 Employee class）时，不会出现异常。我错过了什么吗？
提前致谢！
检查您使用的是哪个版本的 jackson-databind。
根据该主题：
如果您使用的是 Spring 5.0.2，则支持的 Jackson 版本是 2.9.2。尽管如此，您绝对应该努力创建一个 Maven 项目。在 IDE 中手动管理依赖项是自找麻烦。