The Spring 4 WebSocket integrates into a Spring MVC application

Question

1. I write the simple web application based on Spring MVC. Everything run Ok. Then I create Endpoint and HandShake class to Terminal (C# Application) communicate with Server via Websocket.

   • WebsocketEndPoint.java:

     public class WebsocketEndPoint extends BinaryWebSocketHandler {
     
         @Override
         public void afterConnectionEstablished(WebSocketSession session) throws Exception {
             System.out.println("After Connection Established !!!!");
         }
     
         @Override
         protected void handleBinaryMessage(WebSocketSession session, BinaryMessage message) throws Exception {
             session.sendMessage(message);
         }
     
         @Override
         public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception {
             System.out.println("After Connection Closed !!!!");
         }
     
     }
     

   • HandshakeInterceptor.java:

      public class HandshakeInterceptor extends HttpSessionHandshakeInterceptor{
     
         @Override
         public boolean beforeHandshake(ServerHttpRequest request,
             ServerHttpResponse response, WebSocketHandler wsHandler,
     Map<String, Object> attributes) throws Exception {
             System.out.println("Before Handshake");
             return super.beforeHandshake(request, response, wsHandler, attributes);
         }
     
         @Override
         public void afterHandshake(ServerHttpRequest request,
     ServerHttpResponse response, WebSocketHandler wsHandler, Exception ex) {
             System.out.println("After Handshake");
             super.afterHandshake(request, response, wsHandler, ex);
         }
     }
     

   • XML to configure the websocket handler and interceptor : websocketconfig.xml

     <beans xmlns="http://www.springframework.org/schema/beans"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns:websocket="http://www.springframework.org/schema/websocket"
         xsi:schemaLocation="
             http://www.springframework.org/schema/beans
             http://www.springframework.org/schema/beans/spring-beans.xsd
             http://www.springframework.org/schema/websocket
             http://www.springframework.org/schema/websocket/spring-websocket.xsd">
     
             <bean id="websocket" class="com.javahash.spring.WebsocketEndPoint"/>
     
             <websocket:handlers>
                 <websocket:mapping path="/PaymentHandler" handler="websocket"/>
                 <websocket:handshake-interceptors>
                 <bean class="com.javahash.spring.HandshakeInterceptor"/>
                 </websocket:handshake-interceptors>
             </websocket:handlers>
     </beans>
     

2. Add websocketconfig.xml into Spring Application context:

   • web.xml:

     <web-app xmlns="http://java.sun.com/xml/ns/j2ee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
         version="2.4">
     
         <display-name>Web server</display-name>
     
         <servlet>
             <servlet-name>webserver</servlet-name>
             <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
             <load-on-startup>1</load-on-startup>
         </servlet>
     
         <servlet-mapping>
             <servlet-name>dispatcher</servlet-name>
             <url-pattern>/</url-pattern>
         </servlet-mapping>
     
         <context-param>
             <param-name>contextConfigLocation</param-name>
             <param-value>
                 /WEB-INF/dispatcher-servlet.xml
                 /WEB-INF/websocketconf.xml
             </param-value>
         </context-param>
     
         <listener>
             <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
         </listener>
     </web-app>
     

3. After adding websocketconfig.xml into Spring Application context:

   • Terminal (C# application) can communicate with Server via Socket but I can not access web.
   • I have WARNING: No mapping found for HTTP request with URI [Spring4MVCHelloWorld/hello]] in DispatcherServlet with name 'dispatcher'

   • dispatcher-servlet.xml:

     <beans xmlns="http://www.springframework.org/schema/beans"
      xmlns:context="http://www.springframework.org/schema/context"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="
      http://www.springframework.org/schema/beans
      http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
      http://www.springframework.org/schema/context
      http://www.springframework.org/schema/context/spring-context-4.0.xsd">
     
         <context:component-scan base-package="com.javahash.spring.controller" />
     
         <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
             <property name="prefix">
                 <value>/WEB-INF/views/</value>
             </property>
             <property name="suffix">
                 <value>.jsp</value>
             </property>
         </bean>
     </beans>
     

   • HelloWorldController.java:

     package com.javahash.spring.controller;
     
     import org.springframework.stereotype.Controller;
     import org.springframework.ui.Model;
     import org.springframework.web.bind.annotation.RequestMapping;
     import org.springframework.web.bind.annotation.RequestParam;
     
     @Controller
     public class HelloWorldController { 
     
         @RequestMapping("/hello")
         public String hello(@RequestParam(value="name", required=false, defaultValue="World") String name, Model model) {
             model.addAttribute("name", name);
             return "helloworld";
         }
     
     }
     

   • It seems @Controller not effect.

Do i miss anything?

Answer 1

I think you're missing <mvc:annotation-driven/> in your dispatcher-servlet.xml file. Spring scanned your Controller beans but Spring MVC did not register your mappings.