tomcat 7.0.50 java websocket implementation gives 404 error
java, javascript, tomcat, websocket
Solution
I have solved it. Problem was very specific to my installation. I had the websocket api .jar being installed in my app's WEB-INF/lib directory as well. Not sure why it was breaking it. can you put some light on the root cause of this behaviour and why it doesn't work when you gave websocket-api.jar in application's WEB-INF/lib along with tomcat's lib?
Problem
I am trying to implement a websocket on tomcat 7.0.50 using annotated endpoints as specified in Java Websocket API (1.0)- JSR 356. Following are the brief steps how I have coded it 1) Write a websocket endpoint using @ServerEndpoint annotation 2) implement @onOpen and @onMessage methods 3) open a websocket using javascript on google chrome. Please find code corresponding to above steps in order 1) STEP 1 & 2 - writing websocket server endpoint: ``` package com.jkweb.websocket; import java.io.IOException; import java.util.HashMap; import java.util.List; import java.util.Map; import javax.websocket.EndpointConfig; import javax.websocket.OnMessage; import javax.websocket.OnOpen; import javax.websocket.Session; import javax.websocket.server.PathParam; import javax.websocket.server.ServerEndpoint; import org.slf4j.Logger; import org.slf4j.LoggerFactory; @ServerEndpoint(value="/websocket/fileuploadtracker") @OnOpen public void open(Session session,EndpointConfig config) { ...... } @OnMessage public void onMessage(Session session, String msg) { try { session.getBasicRemote().sendText(msg); } catch (IOException e) { logger.error(e.getMessage()); } } public static void sendMessage(String uniqueTocken,String msg){ try { Session wsSession = socketConnectionMap.get(uniqueTocken); wsSession.getBasicRemote().sendText(msg); } catch (IOException e) { logger.error(e.getMessage()); } } ``` } 2) STEP 3 - opening websocket using javascript api in chrome: ``` wsurl = "ws://localhost:8080/jkweb/websocket/fileuploadtracker", ws; ws = new WebSocket(wsurl); ws.onopen = function() { // Web Socket is connected, send data using send() ws.send("Sending first Message"); alert("Message is sent..."); }; ws.onmessage = function (evt) { var received_msg = evt.data; alert("Message is received..."); }; ws.onclose = function(evt) { // websocket is closed. alert("Connection is closed..."+evt.code + ":"+evt.reason ); }; ``` I am using following versions of softwares : 1) Tomcat - 7.0.50 2) Java - 1.7.45 3) Servlet - 3.0 4) Have included following Maven dependency 5) Chrome - 32.0.1700.107m ``` <dependency> <groupId>javax.websocket</groupId> <artifactId>javax.websocket-api</artifactId> <version>1.0</version> <scope>provided</scope> </dependency> ``` However I am getting following error and connection is closed with 1066 error code in chrome's console: ``` WebSocket connection to 'ws://localhost:8080/jkweb/websocket/fileuploadtracker' failed: Error during WebSocket handshake: Unexpected response code: 404 ``` Is there any configuration I am missing out on. I tried to search a lot but couldn't find anything. Please I need this to be solved ASAP.