【发布时间】：2019-01-18 13:25:15
【问题描述】：
我在客户端使用 JavaScript 并在服务器上使用 Java/Tomcat 实现 Web Socket。它在本地主机上工作得很好，但是当我在远程主机上部署时它失败了。检查控制台，我在 Web 套接字请求上收到 500 错误。因此我检查服务器错误日志以查看错误并找到 -
java.lang.UnsupportedOperationException: HTTP upgrade is not supported by this protocol
at org.apache.coyote.AbstractProcessor.doHttpUpgrade(AbstractProcessor.java:712) ~[tomcat-coyote.jar:8.5.20]
at org.apache.coyote.AbstractProcessor.action(AbstractProcessor.java:478) ~[tomcat-coyote.jar:8.5.20]
at org.apache.coyote.Request.action(Request.java:433) ~[tomcat-coyote.jar:8.5.20]
at org.apache.catalina.connector.Request.upgrade(Request.java:2022) ~[catalina.jar:8.5.20]
at org.apache.catalina.connector.RequestFacade.upgrade(RequestFacade.java:1115) ~[catalina.jar:8.5.20]
at org.apache.tomcat.websocket.server.UpgradeUtil.doUpgrade(UpgradeUtil.java:234) ~[tomcat-websocket-8.5.20.jar:8.5.20]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:77) ~[tomcat-websocket-8.5.20.jar:8.5.20]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[catalina.jar:8.5.20]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[catalina.jar:8.5.20]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) [catalina.jar:8.5.20]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [catalina.jar:8.5.20]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478) [catalina.jar:8.5.20]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [catalina.jar:8.5.20]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80) [catalina.jar:8.5.20]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [catalina.jar:8.5.20]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [catalina.jar:8.5.20]
at org.apache.coyote.ajp.AjpProcessor.service(AjpProcessor.java:486) [tomcat-coyote.jar:8.5.20]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-coyote.jar:8.5.20]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-coyote.jar:8.5.20]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1457) [tomcat-coyote.jar:8.5.20]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-coyote.jar:8.5.20]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_11]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_11]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-util.jar:8.5.20]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_11]
我做了一些研究，偶然发现有人遇到类似问题并在这个问题中提出WebSockets through Apache and Tomcat: HTTP upgrade is not supported by the AJP protocol，但我在共享托管服务器上运行私有 tomcat 实例，因此我无法实现该答案中提供的解决方案，因此我联系我的房东，他们会回复
'在调查您的查询时，我们可以看到，按照您电子邮件中提到的步骤更改 tomcat 和 HTTP 设置将影响另一个共享 tomcat 实例的 AJP 连接配置，并且共享 tomcat 实例托管的应用程序将不行。对于重新编译，连接器设置还需要服务器范围的更新，而这不能在共享服务器环境中完成。我们要求您通过访问以下链接来试用我们的 VPS 计划。'
我认为购买 vps 计划应该是最后的手段。有没有人能更有效地解决这个问题。
【问题讨论】：
标签： javascript java apache tomcat java-websocket