一、今天在创建了一个Kotlin+Spring的项目，结果启动报错
org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:155) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at net.AppKt.main(App.kt:26) [classes/:na]
Caused by: org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:126) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:86) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:409) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:174) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:179) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:152) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
... 8 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'httpPutFormContentFilter' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.web.servlet.filter.OrderedHttpPutFormContentFilter]: Factory method 'httpPutFormContentFilter' threw exception; nested exception is java.lang.NoClassDefFoundError: kotlin/reflect/KotlinReflectionInternalError
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:587) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1250) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1099) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:541) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:501) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.getOrderedBeansOfType(ServletContextInitializerBeans.java:225) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAsRegistrationBean(ServletContextInitializerBeans.java:181) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAsRegistrationBean(ServletContextInitializerBeans.java:176) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAdaptableBeans(ServletContextInitializerBeans.java:158) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.<init>(ServletContextInitializerBeans.java:80) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.getServletContextInitializerBeans(ServletWebServerApplicationContext.java:250) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.selfInitialize(ServletWebServerApplicationContext.java:237) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatStarter.onStartup(TomcatStarter.java:54) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5204) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1421) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1411) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_161]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_161]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_161]
at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_161]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.web.servlet.filter.OrderedHttpPutFormContentFilter]: Factory method 'httpPutFormContentFilter' threw exception; nested exception is java.lang.NoClassDefFoundError: kotlin/reflect/KotlinReflectionInternalError
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:579) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
... 24 common frames omitted
Caused by: java.lang.NoClassDefFoundError: kotlin/reflect/KotlinReflectionInternalError
at com.fasterxml.jackson.module.kotlin.KotlinModule.setupModule(KotlinModule.kt:44) ~[jackson-module-kotlin-2.8.4.jar:2.8.4]
at com.fasterxml.jackson.databind.ObjectMapper.registerModule(ObjectMapper.java:751) ~[jackson-databind-2.9.5.jar:2.9.5]
at org.springframework.http.converter.json.Jackson2ObjectMapperBuilder.registerWellKnownModulesIfAvailable(Jackson2ObjectMapperBuilder.java:766) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.http.converter.json.Jackson2ObjectMapperBuilder.configure(Jackson2ObjectMapperBuilder.java:624) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.http.converter.json.Jackson2ObjectMapperBuilder.build(Jackson2ObjectMapperBuilder.java:608) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.<init>(MappingJackson2HttpMessageConverter.java:59) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter.<init>(AllEncompassingFormHttpMessageConverter.java:74) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.filter.HttpPutFormContentFilter.<init>(HttpPutFormContentFilter.java:64) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.boot.web.servlet.filter.OrderedHttpPutFormContentFilter.<init>(OrderedHttpPutFormContentFilter.java:29) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration.httpPutFormContentFilter(WebMvcAutoConfiguration.java:163) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$$EnhancerBySpringCGLIB$$f2471238.CGLIB$httpPutFormContentFilter$1(<generated>) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$$EnhancerBySpringCGLIB$$f2471238$$FastClassBySpringCGLIB$$9f061c7c.invoke(<generated>) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) ~[spring-core-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:361) ~[spring-context-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$$EnhancerBySpringCGLIB$$f2471238.httpPutFormContentFilter(<generated>) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_161]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_161]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_161]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
... 25 common frames omitted
Caused by: java.lang.ClassNotFoundException: kotlin.reflect.KotlinReflectionInternalError
at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_161]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_161]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338) ~[na:1.8.0_161]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_161]
... 45 common frames omitted二、一看到这么多错误日志，很多同学直接懵了，其实有用的就在最后两个Caused By
Caused by: java.lang.NoClassDefFoundError: kotlin/reflect/KotlinReflectionInternalError
at com.fasterxml.jackson.module.kotlin.KotlinModule.setupModule(KotlinModule.kt:44) ~[jackson-module-kotlin-2.8.4.jar:2.8.4]
at com.fasterxml.jackson.databind.ObjectMapper.registerModule(ObjectMapper.java:751) ~[jackson-databind-2.9.5.jar:2.9.5]
at org.springframework.http.converter.json.Jackson2ObjectMapperBuilder.registerWellKnownModulesIfAvailable(Jackson2ObjectMapperBuilder.java:766) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.http.converter.json.Jackson2ObjectMapperBuilder.configure(Jackson2ObjectMapperBuilder.java:624) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.http.converter.json.Jackson2ObjectMapperBuilder.build(Jackson2ObjectMapperBuilder.java:608) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.<init>(MappingJackson2HttpMessageConverter.java:59) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter.<init>(AllEncompassingFormHttpMessageConverter.java:74) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.filter.HttpPutFormContentFilter.<init>(HttpPutFormContentFilter.java:64) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.boot.web.servlet.filter.OrderedHttpPutFormContentFilter.<init>(OrderedHttpPutFormContentFilter.java:29) ~[spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration.httpPutFormContentFilter(WebMvcAutoConfiguration.java:163) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$$EnhancerBySpringCGLIB$$f2471238.CGLIB$httpPutFormContentFilter$1(<generated>) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$$EnhancerBySpringCGLIB$$f2471238$$FastClassBySpringCGLIB$$9f061c7c.invoke(<generated>) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) ~[spring-core-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:361) ~[spring-context-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$$EnhancerBySpringCGLIB$$f2471238.httpPutFormContentFilter(<generated>) ~[spring-boot-autoconfigure-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_161]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_161]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_161]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
... 25 common frames omitted
Caused by: java.lang.ClassNotFoundException: kotlin.reflect.KotlinReflectionInternalError
at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_161]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_161]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338) ~[na:1.8.0_161]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_161]
... 45 common frames omitted三、下面我们来google搜一搜
java.lang.ClassNotFoundException: kotlin.reflect.Kotlin Reflect Internal Error
四、点击第一个看一看
这里写链接内容
这个高分哥们说，他升级了Kotlin版本和Jackson版本后就好了 
五、那么我们也来更新一下
1.先来更新Kotlin的版本，1.2.30 
2.再来搜搜，看看jackson-module-kotlin:版本更新到哪里了 
以前配的是2.8.4，可能太老了
compile "com.fasterxml.jackson.module:jackson-module-kotlin:2.8.4"
3.将2.9版本的配上去 
六、启动成功了，现在问题解决了 
好啦，结束啦！
