Grails 2.4 Traditional WebSocket Example | Grails Chat Application | Traditional Web Socket Chat Example
At first you need to create a configurator class under src/groovy as below:
import javax.websocket.HandshakeResponse import javax.websocket.server.HandshakeRequest import javax.websocket.server.ServerEndpointConfig /** * Created by pritom on 5/10/2017. */ class TraditionalWebSocketConfigurator extends ServerEndpointConfig.Configurator { @Override public void modifyHandshake(ServerEndpointConfig config, HandshakeRequest request, HandshakeResponse response) { config.userProperties.put("MyKey", 100) config.userProperties.put("session", request.httpSession) } }
Next you have to create a Handler class under scr/groovy as below:
import org.springframework.scheduling.TaskScheduler import org.springframework.scheduling.concurrent.ConcurrentTaskScheduler import javax.servlet.ServletContext import javax.servlet.annotation.WebListener import javax.websocket.* import javax.websocket.server.ServerContainer import javax.websocket.server.ServerEndpoint /** * Created by pritom on 5/10/2017. */ @WebListener @ServerEndpoint(value = "/WebSocket/traditional", configurator = TraditionalWebSocketConfigurator.class) class TraditionalWebSocketHandler { private static List<Session> clients = [] private static TaskScheduler clientRemoveScheduler = new ConcurrentTaskScheduler() @OnOpen public void handleOpen(Session userSession, EndpointConfig endpointConfig) { clients.add(userSession) println "WE HAVE OPEN SESSION #${userSession.id} " + "SESSION ${userSession.userProperties.session.id}" } @OnMessage public void handleMessage(String message, Session userSession) throws IOException { if (message) { println("SENDING TO ${clients.findAll { it.isOpen() }.size()}/${clients.size()} CLIENTS") message = "${userSession.id}: ${message}".toString() clients.findAll { it.isOpen() }.each { it.basicRemote.sendText(message) } } } @OnClose public void handeClose(Session userSession) throws SocketException { println "ONE CONNECTION CLOSED" } @OnError public void handleError(Throwable throwable) { println("HANDLE ERROR") throwable.printStackTrace() } static void init(final ServletContext servletContext) { final ServerContainer serverContainer = servletContext.getAttribute("javax.websocket.server.ServerContainer") serverContainer.addEndpoint(TraditionalWebSocketHandler) serverContainer.defaultMaxSessionIdleTimeout = 0 clientRemoveScheduler.scheduleAtFixedRate(new Runnable() { @Override public void run() { try { clients.removeAll { !it.isOpen() } } catch (Exception ex) { } } }, 1000L * 10) } }
Next step is to init Handler from BootStrap.groovy as below:
import com.socket.TraditionalWebSocketHandler import org.codehaus.groovy.grails.commons.GrailsApplication import javax.servlet.ServletContext class BootStrap { ServletContext servletContext GrailsApplication grailsApplication def init = { servletContext -> TraditionalWebSocketHandler.init(servletContext) } def destroy = { } }
You are already done, next step is to generate a view to show chat window:
class SocketController { def index() { session.name = "Pritom Kumar" render view: "index" } }
<html> <head> <asset:javascript src="jquery-2.1.3.js"/> </head> <body> <table> <tr> <td>User Message</td> <td><input type="text" autofocus class="message" required/></td> </tr> <tr> <td></td> <td><input class="button" type="button" value="Send"/></td> </tr> </table> <div class="log_div"></div> <script type="text/javascript"> var socket = new WebSocket("ws://localhost:8807/socket-chat-application/WebSocket/traditional"); socket.onopen = function () { socket.send('Hello'); }; socket.onmessage = function (message) { $(".log_div").prepend("<div>" + message.data + "</div>"); }; socket.onclose = function () { }; socket.onerror = function () { }; $(".button").click(function () { var value = $.trim($(".message").val()); if (value.length > 0) { socket.send(value); $(".message").val("").focus(); } }); $(".message").keypress(function (e) { if (e.keyCode == 13) { $(".button").click(); } }); </script> </body> </html>
And finally below is a screenshot of browser interaction:
