问题1 org.apache.tomcat.websocket.server.WsServerContainer cannot be cast to javax.websocket.server

严重: Servlet.service() for servlet [SpringMVC] in context with path [/ZHDM] threw exception [Request processing failed; nested exception is org.springframework.web.socket.server.HandshakeFailureException: Uncaught failure for request http://125.221.225.118:8080/ZHDM/websocket; nested exception is java.lang.ClassCastException: org.apache.tomcat.websocket.server.WsServerContainer cannot be cast to javax.websocket.server.ServerContainer] with root cause
java.lang.ClassCastException: org.apache.tomcat.websocket.server.WsServerContainer cannot be cast to javax.websocket.server.ServerContainer
	at org.springframework.web.socket.server.standard.AbstractStandardUpgradeStrategy.getContainer(AbstractStandardUpgradeStrategy.java:76)
	at org.springframework.web.socket.server.standard.TomcatRequestUpgradeStrategy.getContainer(TomcatRequestUpgradeStrategy.java:85)
	at org.springframework.web.socket.server.standard.TomcatRequestUpgradeStrategy.getContainer(TomcatRequestUpgradeStrategy.java:47)
	at org.springframework.web.socket.server.standard.AbstractStandardUpgradeStrategy.getSupportedExtensions(AbstractStandardUpgradeStrategy.java:68)
	at org.springframework.web.socket.server.support.DefaultHandshakeHandler.doHandshake(DefaultHandshakeHandler.java:206)
	at org.springframework.web.socket.server.support.WebSocketHttpRequestHandler.handleRequest(WebSocketHttpRequestHandler.java:120)
	at org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter.handle(HttpRequestHandlerAdapter.java:51)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:301)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:136)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:74)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1015)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:652)
	at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:277)
	at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2451)
	at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2440)
	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:744)

出现这个问题的原因是，apache的websocket包和javax-servlet包冲突了，找到Apache Tomcat的webApp目录，打开你部署的项目文件夹，依次打开WEB-INF/lib，找到javaee-api-7.0.jar，删除，再重新启动项目。