java.lang.ClassNotFoundException: edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHashMap

org.springframework.beans.factory.BeanCreationException: Error creating bean with name '_messageBrokerDefaultHandlerMapping': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '_messageBroker': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanInitializationException: MessageBroker initialization failed; nested exception is java.lang.NoClassDefFoundError: edu/emory/mathcs/backport/java/util/concurrent/ConcurrentHashMap
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:527)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:442)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:458)
at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:339)
at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:306)
at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:127)
at javax.servlet.GenericServlet.init(GenericServlet.java:160)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1266)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1185)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1080)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5015)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5302)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:895)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:871)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:615)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1099)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1621)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name '_messageBroker': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanInitializationException: MessageBroker initialization failed; nested exception is java.lang.NoClassDefFoundError: edu/emory/mathcs/backport/java/util/concurrent/ConcurrentHashMap
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1420)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
at org.springframework.beans.factory.support.AbstractBeanFactory.isSingleton(AbstractBeanFactory.java:396)
at org.springframework.context.support.AbstractApplicationContext.isSingleton(AbstractApplicationContext.java:1095)
at org.springframework.web.servlet.handler.AbstractUrlHandlerMapping.registerHandler(AbstractUrlHandlerMapping.java:382)
at org.springframework.web.servlet.handler.SimpleUrlHandlerMapping.registerHandlers(SimpleUrlHandlerMapping.java:129)
at org.springframework.web.servlet.handler.SimpleUrlHandlerMapping.initApplicationContext(SimpleUrlHandlerMapping.java:104)
at org.springframework.context.support.ApplicationObjectSupport.initApplicationContext(ApplicationObjectSupport.java:119)
at org.springframework.web.context.support.WebApplicationObjectSupport.initApplicationContext(WebApplicationObjectSupport.java:72)
at org.springframework.context.support.ApplicationObjectSupport.setApplicationContext(ApplicationObjectSupport.java:73)
at org.springframework.context.support.ApplicationContextAwareProcessor.invokeAwareInterfaces(ApplicationContextAwareProcessor.java:106)
at org.springframework.context.support.ApplicationContextAwareProcessor.postProcessBeforeInitialization(ApplicationContextAwareProcessor.java:85)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:394)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1413)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
... 31 more
Caused by: org.springframework.beans.factory.BeanInitializationException: MessageBroker initialization failed; nested exception is java.lang.NoClassDefFoundError: edu/emory/mathcs/backport/java/util/concurrent/ConcurrentHashMap
at org.springframework.flex.core.MessageBrokerFactoryBean.afterPropertiesSet(MessageBrokerFactoryBean.java:185)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1477)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417)
... 50 more
Caused by: java.lang.NoClassDefFoundError: edu/emory/mathcs/backport/java/util/concurrent/ConcurrentHashMap
at org.springframework.flex.core.MessageBrokerFactoryBean.afterPropertiesSet(MessageBrokerFactoryBean.java:160)
... 52 more
Caused by: java.lang.ClassNotFoundException: edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHashMap
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1711)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1556)
... 53 more

异常原因：缺少jar包！
解决方法：引入 backport-util-concurrent-2.2.jar