Update appengine-flex websocket usage (GoogleCloudPlatform#1526)

Author: joakime

appengine-java8/websocket-jetty/src/main/java/com/example/flexible/websocket/jettynative/EchoServlet.java

@@ -17,17 +17,27 @@
 package com.example.flexible.websocket.jettynative;
 
 import javax.servlet.annotation.WebServlet;
+
+import org.eclipse.jetty.websocket.servlet.ServletUpgradeRequest;
+import org.eclipse.jetty.websocket.servlet.ServletUpgradeResponse;
+import org.eclipse.jetty.websocket.servlet.WebSocketCreator;
 import org.eclipse.jetty.websocket.servlet.WebSocketServlet;
 import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
 
 /*
- * Server-side WebSocket registered as /echo servlet.
+ * Server-side WebSocket upgraded on /echo servlet.
  */
 @SuppressWarnings("serial")
 @WebServlet(name = "Echo WebSocket Servlet", urlPatterns = { "/echo" })
-public class EchoServlet extends WebSocketServlet {
+public class EchoServlet extends WebSocketServlet implements WebSocketCreator {
   @Override
   public void configure(WebSocketServletFactory factory) {
-    factory.register(ServerSocket.class);
+    factory.setCreator(this);
+  }
+
+  @Override
+  public Object createWebSocket(ServletUpgradeRequest servletUpgradeRequest,
+      ServletUpgradeResponse servletUpgradeResponse) {
+    return new ServerSocket();
   }
 }

appengine-java8/websocket-jetty/src/main/java/com/example/flexible/websocket/jettynative/SendServlet.java

@@ -26,6 +26,8 @@
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
+
+import org.eclipse.jetty.client.HttpClient;
 import org.eclipse.jetty.http.HttpStatus;
 import org.eclipse.jetty.util.ssl.SslContextFactory;
 import org.eclipse.jetty.websocket.api.Session;
@@ -52,10 +54,12 @@ public class SendServlet extends HttpServlet {
   // GAE_SERVICE environment variable is set to the GCP service name.
   private static final String GAE_SERVICE_ENV_VAR = "GAE_SERVICE";
 
+  private final HttpClient httpClient;
   private final WebSocketClient webSocketClient;
   private final ClientSocket clientSocket;
 
   public SendServlet() {
+    this.httpClient = createHttpClient();
     this.webSocketClient = createWebSocketClient();
     this.clientSocket = new ClientSocket();
   }
@@ -73,22 +77,31 @@ public void doPost(HttpServletRequest request, HttpServletResponse response) thr
     }
   }
 
-  private WebSocketClient createWebSocketClient() {
-    WebSocketClient webSocketClient;
+  private HttpClient createHttpClient() {
+    HttpClient httpClient;
     if (System.getenv(GAE_INSTANCE_VAR) != null) {
       // If on HTTPS, create client with SSL Context
-      SslContextFactory sslContextFactory = new SimpleContainerScope(
-              WebSocketPolicy.newClientPolicy())
-              .getSslContextFactory();
-      webSocketClient = new WebSocketClient(sslContextFactory);
+      SslContextFactory sslContextFactory = new SslContextFactory();
+      httpClient = new HttpClient(sslContextFactory);
     } else {
       // local testing on HTTP
-      webSocketClient = new WebSocketClient();
+      httpClient = new HttpClient();
     }
-    return webSocketClient;
+    return httpClient;
+  }
+
+  private WebSocketClient createWebSocketClient() {
+    return new WebSocketClient(this.httpClient);
   }
 
   private void sendMessageOverWebSocket(String message) throws Exception {
+    if (!httpClient.isRunning()) {
+      try {
+        httpClient.start();
+      } catch (URISyntaxException e) {
+        e.printStackTrace();
+      }
+    }
     if (!webSocketClient.isRunning()) {
       try {
         webSocketClient.start();

appengine-java8/websocket-jetty/src/main/java/com/example/flexible/websocket/jettynative/ServerSocket.java

@@ -20,40 +20,44 @@
 import java.util.logging.Logger;
 import org.eclipse.jetty.websocket.api.Session;
 import org.eclipse.jetty.websocket.api.WebSocketAdapter;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
+import org.eclipse.jetty.websocket.api.annotations.WebSocket;
 
 /*
  * Server-side WebSocket : echoes received message back to client.
  */
-public class ServerSocket extends WebSocketAdapter {
+@WebSocket(maxTextMessageSize = 64 * 1024)
+public class ServerSocket {
   private Logger logger = Logger.getLogger(SendServlet.class.getName());
+  private Session session;
 
-  @Override
+  @OnWebSocketConnect
   public void onWebSocketConnect(Session session) {
-    super.onWebSocketConnect(session);
+    this.session = session;
     logger.fine("Socket Connected: " + session);
   }
 
-  @Override
+  @OnWebSocketMessage
   public void onWebSocketText(String message) {
-    super.onWebSocketText(message);
     logger.fine("Received message: " + message);
     try {
       // echo message back to client
-      getRemote().sendString(message);
+      this.session.getRemote().sendString(message);
     } catch (IOException e) {
       logger.severe("Error echoing message: " + e.getMessage());
     }
   }
 
-  @Override
+  @OnWebSocketClose
   public void onWebSocketClose(int statusCode, String reason) {
-    super.onWebSocketClose(statusCode, reason);
     logger.fine("Socket Closed: [" + statusCode + "] " + reason);
   }
 
-  @Override
+  @OnWebSocketError
   public void onWebSocketError(Throwable cause) {
-    super.onWebSocketError(cause);
     logger.severe("Websocket error : " + cause.getMessage());
   }
 }