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  1. Org.apache.tomcat.websocket.server.wsservercontainer
  2. Tomcat Websocket Onmessage
HTTP Status 500 – Internal Server Error -------------------------------------------------------------------------------- Type Exception Report Description The server encountered an unexpected condition that prevented it from fulfilling the request. Exception java.lang.NullPointerException controller.UserRegistration.doPost( javax.servlet.http.HttpServlet.service( javax.servlet.http.HttpServlet.service( org.apache.tomcat.websocket.server.WsFilter.doFilter( Note The full stack trace of the root cause is available in the server logs.
im not able to solve this error,im not able continue project,give some suggestion to solve this problem.

Troubleshooting a classpath problem

WebSocket 支持简介Tomcat 支持由 RFC 6455 所定义的 WebSocket。应用开发Tomcat 实现由 JSR-356 定义的 Java WebSocket 1.1 API。 关于 WebSocket API 的使用方法,可查看相关范例,既需要查看客户端 HTML 代码,也来自Tomcat 教程,w3cschool编程狮。. Tomcat7 支持 websocket协议. 看看你的pom文件里有没有引入 javax.websocket这个东西, 这个和tomcat7自带的冲突,把这个删掉就好了,我的是这个情况 tomcat8、tomcat9 不会出现这种情况,官网也说了tomcat8可以更好的兼容webs. The property is org.apache.tomcat.websocket.IOTIMEOUTMS and is the timeout as a String in milliseconds. The default is 5000 (5 seconds). When using the WebSocket client to connect to secure server endpoints, the client SSL configuration is controlled by the userProperties of the provided javax.websocket.ClientEndpointConfig. Org.apache.tomcat.websocket.server.WsFilter.doFilter( note The full stack trace of the root cause is available in the Apache Tomcat/7.0.55 logs. Please can any one suggest what could be going wrong.I think this is something with Tomcat setting.I have checked the JREHOME and JAVAHOME Varible in system variables.

Let's say we have a WAR web application working in development, but when deploying to a server the following error occurs:


This error occurs because an implementation class is cast to an incompatible interface. Several questions can be made in this situation:

  • are there any overlapping jars, with different versions of the same class?
  • Are the multiple versions of the same class all identical or not ?
  • where are the different versions of a given class located ?
  • which class loader is loading which version of a given class ?
  • What does the chain of classloaders look like, how are the class loaders configured ?

The following command answers these questions:


Identifying the problem

A report is printed with classpath troubleshooting information. One of the most common source of classpath problems is overlapping jar files, that contain different versions of the same class. This is an example of a real production example of a jar overlap report for a web application:

In this case the cause of the problem is different. This part of the report shows that an interface is being loaded from the WEB-INF/lib class loader, but there are two versions - one at the WAR level and the other at a server class loader level:

Tomcat Websocket Onmessage

The implementation class, unlike the interface is being loaded from the server/lib folder:

The implementation class ApacheValidationProvider implements the interface ValidationProvider that is visible at the level of the server/lib class loader. That implementation class cannot see the version of ValidationProvider at the level of the WAR WEB-INF/lib. The two interfaces exist on different class loaders so they are not equivalent.

When the program tries to cast the implementation class ApacheValidationProvider at the server/lib level to the interface ValidationProvider at the WEB-INF/lib classloader, the result is ClassCastException.