环境:maven+eclipse+jdk1.8 [tomcat使用的是maven自带的插件,实质原因就是出在tomcat版本问题]
背景:在进行SSM集成WebSocket的时候，项目启动报org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘webSocketHandlerMapping‘ defined in class path resource错误，详细如下
org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘webSocketHandlerMapping‘ defined in class path resource [org/springframework/web/socket/config/annotation/DelegatingWebSocketConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.HandlerMapping]: Factory method ‘webSocketHandlerMapping‘ threw exception; nested exception is java.lang.IllegalStateException: No suitable default RequestUpgradeStrategy found at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1177) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1071) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:312) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:308) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:443) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:325) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4135) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4630) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045) at org.apache.catalina.core.StandardHost.start(StandardHost.java:785) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045) at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:445) at org.apache.catalina.startup.Embedded.start(Embedded.java:825) at org.codehaus.mojo.tomcat.AbstractRunMojo.startContainer(AbstractRunMojo.java:558) at org.codehaus.mojo.tomcat.AbstractRunMojo.execute(AbstractRunMojo.java:255) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:132) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80) at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51) at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:120) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:347) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:154) at org.apache.maven.cli.MavenCli.execute(MavenCli.java:584) at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:213) at org.apache.maven.cli.MavenCli.main(MavenCli.java:157) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289) at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229) at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415) at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356) at org.codehaus.classworlds.Launcher.main(Launcher.java:46)
分析:项目启动日志如下,我是使用maven build -->tomcat:run 进行启动的，可以看到 使用maven 默认的tomcat插件，启动的是tomcat 6.0.29 。版本太低了！
[INFO] <<< tomcat-maven-plugin:1.1:run (default-cli) < compile [INFO] [INFO] --- tomcat-maven-plugin:1.1:run (default-cli) @ [INFO] Using existing Tomcat server configuration at 九月 10, 2018 7:01:23 下午 org.apache.catalina.startup.Embedded start 信息: Starting tomcat server 九月 10, 2018 7:01:23 下午 org.apache.catalina.core.StandardEngine start 信息: Starting Servlet Engine: Apache Tomcat/6.0.29 九月 10, 2018 7:01:23 下午 org.apache.catalina.core.ApplicationContext log 信息: Set web app root system property: 九月 10, 2018 7:01:23 下午 org.apache.catalina.core.ApplicationContext log 信息: Initializing log4j from [classpath:log4j.properties] 九月 10, 2018 7:01:23 下午 org.apache.catalina.core.ApplicationContext log 信息: Initializing Spring root WebApplicationContext
解决:使用maven的tomcat插件 tomcat7进行启动。在pom.xml文件中追加如下配置,在进行maven build-->tomcat7:run进行启动。
<build>
<plugins>
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.2</version>
</plugin>
</plugins>
</build>
备注:如果不是通过maven 命令启动时，仅仅修改tomcat的版本就可以了。