├── .gitignore
├── src
    └── main
    │   ├── webapp
    │       ├── WEB-INF
    │       │   ├── logging.properties
    │       │   ├── appengine-web.xml
    │       │   └── web.xml
    │       ├── stylesheets
    │       │   └── main.css
    │       └── chat.jsp
    │   └── java
    │       └── com
    │           └── google
    │               └── appengine
    │                   └── demos
    │                       └── websocketchat
    │                           ├── servlet
    │                               ├── StopServlet.java
    │                               └── StartupServlet.java
    │                           ├── server
    │                               ├── ChatSocketServerShutdownHook.java
    │                               ├── MetaInfoManager.java
    │                               └── ChatSocketServer.java
    │                           ├── message
    │                               ├── ParticipantListMessage.java
    │                               ├── OutgoingMessage.java
    │                               └── ChatMessage.java
    │                           └── domain
    │                               ├── WebSocketServerNode.java
    │                               └── ChatRoomParticipants.java
├── nbactions.xml
├── README.md
├── CONTRIB.md
├── pom.xml
└── LICENSE


/.gitignore:
--------------------------------------------------------------------------------
 1 | hotspot.log
 2 | *.iml
 3 | *.ipr
 4 | *.iws
 5 | target/
 6 | classes/
 7 | /var
 8 | pom.xml.versionsBackup
 9 | test-output/
10 | /atlassian-ide-plugin.xml
11 | .idea
12 | .DS_Store
13 | .classpath
14 | .settings
15 | .project
16 | test-output
17 | .externalToolBuilders
18 | *~
19 | 


--------------------------------------------------------------------------------
/src/main/webapp/WEB-INF/logging.properties:
--------------------------------------------------------------------------------
 1 | #
 2 | # Copyright (c) 2013 Google Inc. All Rights Reserved.
 3 | #
 4 | # Licensed under the Apache License, Version 2.0 (the "License"); you
 5 | # may not use this file except in compliance with the License. You may
 6 | # obtain a copy of the License at
 7 | #
 8 | #     http://www.apache.org/licenses/LICENSE-2.0
 9 | #
10 | # Unless required by applicable law or agreed to in writing, software
11 | # distributed under the License is distributed on an "AS IS" BASIS,
12 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
13 | # implied. See the License for the specific language governing
14 | # permissions and limitations under the License.
15 | #
16 | 
17 | # A default java.util.logging configuration.
18 | # (All App Engine logging is through java.util.logging by default).
19 | #
20 | # To use this configuration, copy it into your application's WEB-INF
21 | # folder and add the following to your appengine-web.xml:
22 | #
23 | # <system-properties>
24 | #   <property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
25 | # </system-properties>
26 | #
27 | 
28 | # Set the default logging level for all loggers to INFO
29 | .level = INFO
30 | 


--------------------------------------------------------------------------------
/nbactions.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <!--
 3 | ~ Copyright (c) 2013 Google Inc. All Rights Reserved.
 4 | ~
 5 | ~ Licensed under the Apache License, Version 2.0 (the "License"); you
 6 | ~ may not use this file except in compliance with the License. You may
 7 | ~ obtain a copy of the License at
 8 | ~
 9 | ~     http://www.apache.org/licenses/LICENSE-2.0
10 | ~
11 | ~ Unless required by applicable law or agreed to in writing, software
12 | ~ distributed under the License is distributed on an "AS IS" BASIS,
13 | ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
14 | ~ implied. See the License for the specific language governing
15 | ~ permissions and limitations under the License.
16 | --><actions>
17 |   <action>
18 |     <actionName>CUSTOM-gcloud</actionName>
19 |     <displayName>gcloud:run</displayName>
20 |     <goals>
21 |       <goal>gcloud:run</goal>
22 |     </goals>
23 |   </action>
24 |   <action>
25 |     <actionName>CUSTOM-gcloud</actionName>
26 |     <displayName>gcloud:deploy</displayName>
27 |     <goals>
28 |       <goal>gcloud:deploy</goal>
29 |     </goals>
30 |   </action>
31 |   <action>
32 |             <actionName>CUSTOM-update</actionName>
33 |             <displayName>update</displayName>
34 |             <goals>
35 |                 <goal>appengine:update</goal>
36 |             </goals>
37 |         </action>
38 | </actions>
39 | 


--------------------------------------------------------------------------------
/src/main/webapp/WEB-INF/appengine-web.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <!--
 3 |   ~ Copyright (c) 2013 Google Inc. All Rights Reserved.
 4 |   ~
 5 |   ~ Licensed under the Apache License, Version 2.0 (the "License"); you
 6 |   ~ may not use this file except in compliance with the License. You may
 7 |   ~ obtain a copy of the License at
 8 |   ~
 9 |   ~     http://www.apache.org/licenses/LICENSE-2.0
10 |   ~
11 |   ~ Unless required by applicable law or agreed to in writing, software
12 |   ~ distributed under the License is distributed on an "AS IS" BASIS,
13 |   ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
14 |   ~ implied. See the License for the specific language governing
15 |   ~ permissions and limitations under the License.
16 |   -->
17 | 
18 | <appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
19 |     <threadsafe>true</threadsafe>
20 |     <vm>true</vm>
21 |     <vm-settings>
22 |         <setting name="machine_type" value="n1-standard-1"/>
23 |         <setting name="forwarded_ports" value="65080"/>
24 |     </vm-settings>
25 |     <manual-scaling>
26 |         <instances>3</instances>
27 |     </manual-scaling>
28 | 
29 |     <sessions-enabled>true</sessions-enabled>
30 |     <precompilation-enabled>false</precompilation-enabled>
31 |     <system-properties>
32 |         <property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
33 |     </system-properties>
34 | </appengine-web-app>
35 | 


--------------------------------------------------------------------------------
/src/main/java/com/google/appengine/demos/websocketchat/servlet/StopServlet.java:
--------------------------------------------------------------------------------
 1 | /*
 2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
 3 |  *
 4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
 5 |  * may not use this file except in compliance with the License. You may
 6 |  * obtain a copy of the License at
 7 |  *
 8 |  *     http://www.apache.org/licenses/LICENSE-2.0
 9 |  *
10 |  * Unless required by applicable law or agreed to in writing, software
11 |  * distributed under the License is distributed on an "AS IS" BASIS,
12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
13 |  * implied. See the License for the specific language governing
14 |  * permissions and limitations under the License.
15 |  */
16 | 
17 | package com.google.appengine.demos.websocketchat.servlet;
18 | 
19 | import com.google.appengine.demos.websocketchat.server.ChatSocketServerShutdownHook;
20 | 
21 | import javax.servlet.ServletException;
22 | import javax.servlet.http.HttpServlet;
23 | import javax.servlet.http.HttpServletRequest;
24 | import javax.servlet.http.HttpServletResponse;
25 | import java.io.IOException;
26 | import java.util.logging.Logger;
27 | 
28 | /**
29 |  * A Servlet called when accessing /_ah/stop.
30 |  */
31 | public class StopServlet extends HttpServlet {
32 | 
33 |   private static final Logger LOG = Logger.getLogger(StopServlet.class.getName());
34 | 
35 |   protected void doGet(HttpServletRequest request, HttpServletResponse response)
36 |       throws ServletException, IOException {
37 |     LOG.info("The stop servlet called.");
38 |     new ChatSocketServerShutdownHook().shutdown();
39 |     response.setStatus(204);
40 |   }
41 | }
42 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | App Engine Java VM Runtime Websocket Chat
 2 | Copyright (C) 2010-2015 Google Inc.
 3 | 
 4 | ## Sample websocket chat application for use with App Engine Java VM Runtime.
 5 | 
 6 | Requires [Apache Maven](http://maven.apache.org) 3.1 or greater, and
 7 | JDK 7+ in order to run.  This application needs to be deployed to the
 8 | [App Engine Managed VMs][1].
 9 | 
10 | 
11 | In order to run this application, you also need to configure the
12 | Compute Engine firewall to allow incoming connections to the port 65080
13 | by default.
14 | 
15 | Here is how to configure the Compute Engine firewall.
16 | 
17 | 1. Go to the [cloud console][https://cloud.google.com/console].
18 | 2. Select your Cloud project.
19 | 3. Select `Compute Engine`
20 | 4. Click the `Network` menu then click the `default` network.
21 | 5. Click `Add Firewall rule` button in the `Firewalls rules` section.
22 | 6. Type `chatservice` in the `Name` field, `0.0.0.0/0` in the Source IP Ranges field
23 |   and `tcp:65080` in the
24 | `Allowed protocols or ports` field, then click `Create` button.
25 | 
26 | Now you're good to go!
27 | 
28 | To build:
29 | 
30 | Install the [Cloud SDK for Managed VMs](https://cloud.google.com/appengine/docs/managed-vms/)
31 | To run the application, do the following:
32 | 
33 | 1. Set the correct Cloud SDK project via `gcloud config set project YOUR_PROJECT`.
34 | 2. Run `mvn gcloud:deploy`
35 | 3. Visit `http://YOUR_PROJECT.appspot.com`.
36 | 
37 | For further information, consult the [Java App
38 | Engine](https://cloud.google.com/appengine/docs/java/managed-vms)
39 | documentation.
40 | 
41 | To see all the available goals for the Cloud SDK plugin, run
42 | 
43 |     mvn help:describe -Dplugin=gcloud
44 | 
45 | [1]: https://cloud.google.com/console
46 | 


--------------------------------------------------------------------------------
/src/main/java/com/google/appengine/demos/websocketchat/server/ChatSocketServerShutdownHook.java:
--------------------------------------------------------------------------------
 1 | /*
 2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
 3 |  *
 4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
 5 |  * may not use this file except in compliance with the License. You may
 6 |  * obtain a copy of the License at
 7 |  *
 8 |  *     http://www.apache.org/licenses/LICENSE-2.0
 9 |  *
10 |  * Unless required by applicable law or agreed to in writing, software
11 |  * distributed under the License is distributed on an "AS IS" BASIS,
12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
13 |  * implied. See the License for the specific language governing
14 |  * permissions and limitations under the License.
15 |  */
16 | 
17 | package com.google.appengine.demos.websocketchat.server;
18 | 
19 | import com.google.appengine.api.LifecycleManager.ShutdownHook;
20 | import com.google.appengine.api.NamespaceManager;
21 | import com.google.appengine.api.utils.SystemProperty;
22 | 
23 | import java.util.logging.Logger;
24 | 
25 | /**
26 |  * An implementation for the ShutdownHook.
27 |  *
28 |  * @see <a href="https://developers.google.com/appengine/docs/java/backends/?hl=ja#Shutdown">
29 |  * Backends Java API Overview#Shutdown</a>
30 |  */
31 | public class ChatSocketServerShutdownHook implements ShutdownHook{
32 | 
33 |   private static final Logger LOG = Logger.getLogger(ShutdownHook.class.getName());
34 | 
35 |   @Override
36 |   public void shutdown() {
37 |     LOG.info("The ChatSocketServerShutdownHook is called.");
38 |     String version = SystemProperty.applicationVersion.get();
39 |     String majorVersion = version.substring(0, version.indexOf('.'));
40 |     NamespaceManager.set(majorVersion);
41 |     LOG.info("Namespace set to " + majorVersion);
42 |     ChatSocketServer.ChatServerBridge chatServerBridge =
43 |         ChatSocketServer.ChatServerBridge.getInstance();
44 |     chatServerBridge.stop();
45 |   }
46 | }
47 | 


--------------------------------------------------------------------------------
/src/main/java/com/google/appengine/demos/websocketchat/message/ParticipantListMessage.java:
--------------------------------------------------------------------------------
 1 | /*
 2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
 3 |  *
 4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
 5 |  * may not use this file except in compliance with the License. You may
 6 |  * obtain a copy of the License at
 7 |  *
 8 |  *     http://www.apache.org/licenses/LICENSE-2.0
 9 |  *
10 |  * Unless required by applicable law or agreed to in writing, software
11 |  * distributed under the License is distributed on an "AS IS" BASIS,
12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
13 |  * implied. See the License for the specific language governing
14 |  * permissions and limitations under the License.
15 |  */
16 | 
17 | package com.google.appengine.demos.websocketchat.message;
18 | 
19 | import com.google.common.collect.ImmutableSet;
20 | import com.google.gson.Gson;
21 | 
22 | import java.util.Set;
23 | 
24 | /**
25 |  * A message for notifying the participant list of the chat room.
26 |  */
27 | public class ParticipantListMessage implements OutgoingMessage {
28 | 
29 |   private MessageType type;
30 | 
31 |   private String room;
32 | 
33 |   private Set<String> participantSet;
34 | 
35 |   /**
36 |    * Creates a ParticipantListMessage instance with the given parameters.
37 |    *
38 |    * @param room a name of the chat room.
39 |    * @param participantSet a set of the names of the participants.
40 |    */
41 |   public ParticipantListMessage(String room, Set<String> participantSet) {
42 |     this.type = MessageType.PARTICIPANTS;
43 |     this.room = room;
44 |     this.participantSet = ImmutableSet.copyOf(participantSet);
45 |   }
46 | 
47 |   @Override
48 |   public MessageType getType() {
49 |     return type;
50 |   }
51 | 
52 |   @Override
53 |   public String toJson(Gson gson) {
54 |     return gson.toJson(this);
55 |   }
56 | 
57 |   @Override
58 |   public boolean shouldSendTo(String room) {
59 |     return this.room.equals(room);
60 |   }
61 | 
62 |   @Override
63 |   public String getRoom() {
64 |     return room;
65 |   }
66 | 
67 |   /**
68 |    * Returns the set of the names of the participants.
69 |    *
70 |    * @return the set of the names of the participants.
71 |    */
72 |   public Set<String> getParticipantSet() {
73 |     return participantSet;
74 |   }
75 | }
76 | 


--------------------------------------------------------------------------------
/src/main/java/com/google/appengine/demos/websocketchat/message/OutgoingMessage.java:
--------------------------------------------------------------------------------
 1 | /*
 2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
 3 |  *
 4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
 5 |  * may not use this file except in compliance with the License. You may
 6 |  * obtain a copy of the License at
 7 |  *
 8 |  *     http://www.apache.org/licenses/LICENSE-2.0
 9 |  *
10 |  * Unless required by applicable law or agreed to in writing, software
11 |  * distributed under the License is distributed on an "AS IS" BASIS,
12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
13 |  * implied. See the License for the specific language governing
14 |  * permissions and limitations under the License.
15 |  */
16 | 
17 | package com.google.appengine.demos.websocketchat.message;
18 | 
19 | import com.google.gson.Gson;
20 | 
21 | /**
22 |  * An interface that is supposed to be passed to {@code ChatSocketServer#sendToClients()} method.
23 |  */
24 | public interface OutgoingMessage {
25 |   /**
26 |    * A type of the message.
27 |    */
28 |   public enum MessageType {
29 |     /** A normal chat message. */
30 |     MESSAGE,
31 | 
32 |     /** A message for notifying the participant list. */
33 |     PARTICIPANTS,
34 | 
35 |     /** A system message. */
36 |     SYSTEM,
37 | 
38 |     /** A message indicating someone entered the room. */
39 |     ENTER,
40 | 
41 |     /** A message indicating someone left the room. */
42 |     LEAVE,
43 | 
44 |     /** A special message for propagating various message between multiple server nodes. */
45 |     PROPAGATE
46 |   }
47 |   /**
48 |    * Returns the type of this message.
49 |    *
50 |    * @return the type of this message.
51 |    */
52 |   public MessageType getType();
53 | 
54 |   /**
55 |    * Returns a JSON object that will be sent to the clients.
56 |    *
57 |    * @param gson a Gson object for serializing this message.
58 |    * @return a JSON object that will be sent to the clients.
59 |    */
60 |   public String toJson(Gson gson);
61 | 
62 |   /**
63 |    * Returns whether or not we should send this message to the given chat room.
64 |    *
65 |    * @param room a name of the chat room.
66 |    * @return whether or not we should send this message to the given chat room.
67 |    */
68 |   public boolean shouldSendTo(String room);
69 | 
70 |   /**
71 |    * Returns the name of the chat room that this message belongs to.
72 |    *
73 |    * @return the name of the chat room that this message belongs to.
74 |    */
75 |   public String getRoom();
76 | }
77 | 


--------------------------------------------------------------------------------
/src/main/webapp/WEB-INF/web.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <!--
 3 |   ~ Copyright (c) 2013 Google Inc. All Rights Reserved.
 4 |   ~
 5 |   ~ Licensed under the Apache License, Version 2.0 (the "License"); you
 6 |   ~ may not use this file except in compliance with the License. You may
 7 |   ~ obtain a copy of the License at
 8 |   ~
 9 |   ~     http://www.apache.org/licenses/LICENSE-2.0
10 |   ~
11 |   ~ Unless required by applicable law or agreed to in writing, software
12 |   ~ distributed under the License is distributed on an "AS IS" BASIS,
13 |   ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
14 |   ~ implied. See the License for the specific language governing
15 |   ~ permissions and limitations under the License.
16 |   -->
17 | 
18 | <web-app
19 |     version="2.5"
20 |     xmlns="http://java.sun.com/xml/ns/javaee"
21 |     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
22 |     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
23 |   <security-constraint>
24 |     <web-resource-collection>
25 |       <url-pattern>/*</url-pattern>
26 |     </web-resource-collection>
27 |     <auth-constraint>
28 |       <role-name>*</role-name>
29 |     </auth-constraint>
30 |   </security-constraint>
31 |   <servlet>
32 |     <servlet-name>startup</servlet-name>
33 |     <servlet-class>com.google.appengine.demos.websocketchat.servlet.StartupServlet
34 |     </servlet-class>
35 |     <load-on-startup>0</load-on-startup>
36 |   </servlet>
37 |   <servlet-mapping>
38 |     <servlet-name>startup</servlet-name>
39 |     <url-pattern>/_ah/start</url-pattern>
40 |   </servlet-mapping>
41 |   <servlet>
42 |     <servlet-name>stop</servlet-name>
43 |     <servlet-class>com.google.appengine.demos.websocketchat.servlet.StopServlet</servlet-class>
44 |   </servlet>
45 |   <servlet-mapping>
46 |     <servlet-name>stop</servlet-name>
47 |     <url-pattern>/_ah/stop</url-pattern>
48 |   </servlet-mapping>
49 |   <filter>
50 |     <filter-name>ObjectifyFilter</filter-name>
51 |     <filter-class>com.googlecode.objectify.ObjectifyFilter</filter-class>
52 |   </filter>
53 |   <filter-mapping>
54 |     <filter-name>ObjectifyFilter</filter-name>
55 |     <url-pattern>/*</url-pattern>
56 |   </filter-mapping>
57 |   <welcome-file-list>
58 |     <welcome-file>chat.jsp</welcome-file>
59 |   </welcome-file-list>
60 |   <security-constraint>
61 |     <web-resource-collection>
62 |       <web-resource-name>top</web-resource-name>
63 |       <url-pattern>/</url-pattern>
64 |     </web-resource-collection>
65 |     <auth-constraint>
66 |       <role-name>*</role-name>
67 |     </auth-constraint>
68 |   </security-constraint>
69 | </web-app>
70 | 


--------------------------------------------------------------------------------
/src/main/webapp/stylesheets/main.css:
--------------------------------------------------------------------------------
  1 | /*
  2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
  3 |  *
  4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
  5 |  * may not use this file except in compliance with the License. You may
  6 |  * obtain a copy of the License at
  7 |  *
  8 |  *     http://www.apache.org/licenses/LICENSE-2.0
  9 |  *
 10 |  * Unless required by applicable law or agreed to in writing, software
 11 |  * distributed under the License is distributed on an "AS IS" BASIS,
 12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 13 |  * implied. See the License for the specific language governing
 14 |  * permissions and limitations under the License.
 15 |  */
 16 | 
 17 | body, html {
 18 |   font-family: 'Marmelad', sans-serif;
 19 |   background-color: #FFFFFF;
 20 |   padding: 0;
 21 |   margin: 0;
 22 |   height: 100%;
 23 | }
 24 | 
 25 | input {
 26 |   padding: .2em .3em;
 27 |   display: inline-block;
 28 |   border: 1px solid #ccc;
 29 |   font-size: .8em;
 30 |   box-shadow: inset 0 1px 3px #ddd;
 31 |   border-radius: 4px;
 32 |   -webkit-transition: .3s linear border;
 33 |   -moz-transition: .3s linear border;
 34 |   -ms-transition: .3s linear border;
 35 |   -o-transition: .3s linear border;
 36 |   transition: .3s linear border;
 37 |   -moz-box-sizing: border-box;
 38 |   -webkit-box-sizing: border-box;
 39 |   box-sizing: border-box;
 40 |   -webkit-font-smoothing: antialiased;
 41 | }
 42 | 
 43 | h2 {
 44 |   margin: 0;
 45 | }
 46 | 
 47 | #header {
 48 |   height: 99px;
 49 |   border-top: 1px solid #FFFFFF;
 50 |   border-left: 1px solid #FFFFFF;
 51 |   border-right: 1px solid #FFFFFF;
 52 | }
 53 | 
 54 | #header h2 {
 55 |   margin: 4px;
 56 | }
 57 | 
 58 | #container {
 59 |   width: 100%;
 60 |   padding: 0;
 61 |   margin: 0 auto;
 62 |   background-color: #0e90d2;
 63 |   height: calc(100% - 102px);
 64 |   height: -moz-calc(100% - 102px);
 65 |   height: -webkit-calc(100% - 102px);
 66 | }
 67 | 
 68 | #participants {
 69 |   background: #dd514c;
 70 |   float: left;
 71 |   width: 149px;
 72 |   height: 100%;
 73 |   overflow: auto;
 74 |   border-top: 1px solid #FFFFFF;
 75 |   border-left: 1px solid #FFFFFF;
 76 |   border-bottom: 1px solid #FFFFFF;
 77 | }
 78 | 
 79 | #participants p {
 80 |   margin: 2px;
 81 | }
 82 | 
 83 | #messages {
 84 |   background: #5eb95e;;
 85 |   float: right;
 86 |   width: calc(100% - 152px);
 87 |   width: -moz-calc(100% - 152px);
 88 |   width: -webkit-calc(100% - 152px);
 89 |   height: 100%;
 90 |   overflow: auto;
 91 |   border: 1px solid #FFFFFF;
 92 | }
 93 | 
 94 | #messages p {
 95 |   margin: 2px;
 96 | }
 97 | 
 98 | .system {
 99 |   font-style: italic;
100 |   color: #dd514c;
101 | }
102 | 


--------------------------------------------------------------------------------
/src/main/java/com/google/appengine/demos/websocketchat/servlet/StartupServlet.java:
--------------------------------------------------------------------------------
 1 | /*
 2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
 3 |  *
 4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
 5 |  * may not use this file except in compliance with the License. You may
 6 |  * obtain a copy of the License at
 7 |  *
 8 |  *     http://www.apache.org/licenses/LICENSE-2.0
 9 |  *
10 |  * Unless required by applicable law or agreed to in writing, software
11 |  * distributed under the License is distributed on an "AS IS" BASIS,
12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
13 |  * implied. See the License for the specific language governing
14 |  * permissions and limitations under the License.
15 |  */
16 | 
17 | package com.google.appengine.demos.websocketchat.servlet;
18 | 
19 | import com.google.appengine.api.LifecycleManager;
20 | import com.google.appengine.api.NamespaceManager;
21 | import com.google.appengine.api.utils.SystemProperty;
22 | import com.google.appengine.demos.websocketchat.domain.ChatRoomParticipants;
23 | import com.google.appengine.demos.websocketchat.domain.WebSocketServerNode;
24 | import com.google.appengine.demos.websocketchat.server.ChatSocketServer;
25 | import com.google.appengine.demos.websocketchat.server.ChatSocketServerShutdownHook;
26 | import com.googlecode.objectify.ObjectifyService;
27 | 
28 | import javax.servlet.ServletException;
29 | import javax.servlet.http.HttpServlet;
30 | import javax.servlet.http.HttpServletRequest;
31 | import javax.servlet.http.HttpServletResponse;
32 | import java.io.IOException;
33 | import java.util.logging.Logger;
34 | 
35 | /**
36 |  * A servlet that is called when accesing /_ah/start.
37 |  */
38 | public class StartupServlet extends HttpServlet {
39 | 
40 |   private static final Logger LOG = Logger.getLogger(StartupServlet.class.getName());
41 | 
42 |   static {
43 |     ObjectifyService.register(WebSocketServerNode.class);
44 |     ObjectifyService.register(ChatRoomParticipants.class);
45 |     LOG.info("The startup servlet called.");
46 |     LifecycleManager.getInstance().setShutdownHook(new ChatSocketServerShutdownHook());
47 |     String version = SystemProperty.applicationVersion.get();
48 |     String majorVersion = version.substring(0, version.indexOf('.'));
49 |     NamespaceManager.set(majorVersion);
50 |     LOG.info("Namespace set to " + majorVersion);
51 |     ChatSocketServer.ChatServerBridge chatServerBridge =
52 |         ChatSocketServer.ChatServerBridge.getInstance();
53 |     chatServerBridge.start();
54 |   }
55 | 
56 |   protected void doGet(HttpServletRequest request, HttpServletResponse response)
57 |       throws ServletException, IOException {
58 |     response.setStatus(204);
59 |   }
60 | }
61 | 


--------------------------------------------------------------------------------
/src/main/java/com/google/appengine/demos/websocketchat/domain/WebSocketServerNode.java:
--------------------------------------------------------------------------------
 1 | /*
 2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
 3 |  *
 4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
 5 |  * may not use this file except in compliance with the License. You may
 6 |  * obtain a copy of the License at
 7 |  *
 8 |  *     http://www.apache.org/licenses/LICENSE-2.0
 9 |  *
10 |  * Unless required by applicable law or agreed to in writing, software
11 |  * distributed under the License is distributed on an "AS IS" BASIS,
12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
13 |  * implied. See the License for the specific language governing
14 |  * permissions and limitations under the License.
15 |  */
16 | 
17 | package com.google.appengine.demos.websocketchat.domain;
18 | 
19 | import com.googlecode.objectify.Key;
20 | import com.googlecode.objectify.annotation.Entity;
21 | import com.googlecode.objectify.annotation.Id;
22 | import com.googlecode.objectify.annotation.Parent;
23 | 
24 | /**
25 |  * An entity class which represents a single websocket server node and holds a number of
26 |  * active connections for this server node.
27 |  */
28 | @Entity
29 | public class WebSocketServerNode {
30 | 
31 |   @Id
32 |   private String webSocketUrl;
33 | 
34 |   @Parent
35 |   private Key<WebSocketServerNode> parentKey;
36 | 
37 |   private long numberOfParticipants;
38 | 
39 |   /**
40 |    * Returns an objectify key commonly used as the parent key for every instance of this class.
41 |    *
42 |    * @return an objectify key commonly used as the parent key for every instance of this class.
43 |    */
44 |   public static Key<WebSocketServerNode> getRootKey() {
45 |     return Key.create(WebSocketServerNode.class, "Root");
46 |   }
47 | 
48 |   /**
49 |    * Returns an objectify key representing the given websocket server node.
50 |    *
51 |    * @param webSocketUrl an identifier of a single server node, in the form of websocket URL,
52 |    *                     e.x. "ws://173.255.112.201:65080/".
53 |    * @return an objectify key representing the given websocket server node.
54 |    */
55 |   public static Key<WebSocketServerNode> getKeyFromWebSocketUrl(String webSocketUrl) {
56 |     return Key.create(getRootKey(), WebSocketServerNode.class, webSocketUrl);
57 |   }
58 | 
59 |   /* Objectify needs the default constructor. */
60 |   private WebSocketServerNode() {
61 |   }
62 | 
63 |   /**
64 |    * Creates an instance representing a single websocket server node.
65 |    *
66 |    * @param webSocketUrl an identifier of a single server node, in the form of websocket URL,
67 |    *                     e.x. "ws://173.255.112.201:65080/".
68 |    */
69 |   public WebSocketServerNode(String webSocketUrl) {
70 |     this.parentKey = getRootKey();
71 |     this.webSocketUrl = webSocketUrl;
72 |     this.numberOfParticipants = 0L;
73 |   }
74 | 
75 |   /**
76 |    * Returns an objectify key representing this entity.
77 |    *
78 |    * @return an objectify key representing this entity.
79 |    */
80 |   public Key<WebSocketServerNode> getKey() {
81 |     return getKeyFromWebSocketUrl(this.webSocketUrl);
82 |   }
83 | }
84 | 


--------------------------------------------------------------------------------
/CONTRIB.md:
--------------------------------------------------------------------------------
 1 | # How to become a contributor and submit your own code
 2 | 
 3 | ## Contributor License Agreements
 4 | 
 5 | We'd love to accept your sample apps and patches! Before we can take them, we have to jump a couple of legal hurdles.
 6 | 
 7 | Please fill out either the individual or corporate Contributor License Agreement (CLA).
 8 | 
 9 |   * If you are an individual writing original source code and you're sure you own the intellectual property, then you'll need to sign an [individual CLA](http://code.google.com/legal/individual-cla-v1.0.html).
10 |   * If you work for a company that wants to allow you to contribute your work, then you'll need to sign a [corporate CLA](http://code.google.com/legal/corporate-cla-v1.0.html).
11 | 
12 | Follow either of the two links above to access the appropriate CLA and instructions for how to sign and return it. Once we receive it, we'll be able to accept your pull requests.
13 | 
14 | ## Contributing A Patch
15 | 
16 | 1. Submit an issue describing your proposed change to the repo in question.
17 | 1. The repo owner will respond to your issue promptly.
18 | 1. If your proposed change is accepted, and you haven't already done so, sign a Contributor License Agreement (see details above).
19 | 1. Fork the desired repo, develop and test your code changes.
20 | 1. Ensure that your code adheres to the existing style in the sample to which you are contributing. Refer to the [Google Cloud Platform Samples Style Guide](https://github.com/GoogleCloudPlatform/Template/wiki/style.html) for the recommended coding standards for this organization.
21 | 1. Ensure that your code has an appropriate set of unit tests which all pass.
22 | 1. Submit a pull request.
23 | 
24 | ## Contributing A New Sample App
25 | 
26 | 1. Submit an issue to the GoogleCloudPlatform/Template repo describing your proposed sample app.
27 | 1. The Template repo owner will respond to your enhancement issue promptly. Instructional value is the top priority when evaluating new app proposals for this collection of repos. 
28 | 1. If your proposal is accepted, and you haven't already done so, sign a Contributor License Agreement (see details above).
29 | 1. Create your own repo for your app following this naming convention:
30 |     * {product}-{app-name}-{language}
31 |     * products: appengine, compute, storage, bigquery, prediction, cloudsql
32 |     * example:  appengine-guestbook-python
33 |     * For multi-product apps, concatenate the primary products, like this: compute-appengine-demo-suite-python.
34 |     * For multi-language apps, concatenate the primary languages like this: appengine-sockets-python-java-go.
35 | 1. Clone the README.md, CONTRIB.md and LICENSE files from the GoogleCloudPlatform/Template repo.
36 | 1. Ensure that your code adheres to the existing style in the sample to which you are contributing. Refer to the [Google Cloud Platform Samples Style Guide](https://github.com/GoogleCloudPlatform/Template/wiki/style.html) for the recommended coding standards for this organization.
37 | 1. Ensure that your code has an appropriate set of unit tests which all pass.
38 | 1. Submit a request to fork your repo in GoogleCloudPlatform organizationt via your proposal issue.
39 | 


--------------------------------------------------------------------------------
/src/main/java/com/google/appengine/demos/websocketchat/message/ChatMessage.java:
--------------------------------------------------------------------------------
  1 | /*
  2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
  3 |  *
  4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
  5 |  * may not use this file except in compliance with the License. You may
  6 |  * obtain a copy of the License at
  7 |  *
  8 |  *     http://www.apache.org/licenses/LICENSE-2.0
  9 |  *
 10 |  * Unless required by applicable law or agreed to in writing, software
 11 |  * distributed under the License is distributed on an "AS IS" BASIS,
 12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 13 |  * implied. See the License for the specific language governing
 14 |  * permissions and limitations under the License.
 15 |  */
 16 | 
 17 | package com.google.appengine.demos.websocketchat.message;
 18 | 
 19 | import com.google.gson.Gson;
 20 | 
 21 | /**
 22 |  * A class that is sent via websocket between the servers and clients.
 23 |  *
 24 |  * The instances are serialized by Gson when being sent via the websocket connection.
 25 |  */
 26 | public class ChatMessage implements OutgoingMessage {
 27 | 
 28 |   private MessageType type;
 29 | 
 30 |   private String name;
 31 | 
 32 |   private String room;
 33 | 
 34 |   private String message;
 35 | 
 36 |   /**
 37 |    * Returns another ChatMessage instance which can be used for propagating the original
 38 |    * OutgoingMessage between multiple websocket server nodes.
 39 |    *
 40 |    * @param original an original OutgoingMessage instance that you want to wrap.
 41 |    * @param gson a Gson object which used for serialization.
 42 |    * @return a new ChatMessage with {@code MessageType = MessageType.PROPAGATE} that wraps the
 43 |    * given original message in the message property.
 44 |    */
 45 |   public static ChatMessage createPropagateMessage(OutgoingMessage original, Gson gson) {
 46 |     return new ChatMessage(MessageType.PROPAGATE, null, original.getRoom(), original.toJson(gson));
 47 |   }
 48 | 
 49 |   /**
 50 |    * Creates a ChatMessage instance with given parameters.
 51 |    *
 52 |    * @param messageType one of the MessageType enum, represents the type of this message.
 53 |    * @param name a name of the message owner.
 54 |    * @param room a name of the chat room that the message belongs to.
 55 |    * @param message actual message contents.
 56 |    */
 57 |   public ChatMessage(MessageType messageType, String name, String room, String message) {
 58 |     this.type = messageType;
 59 |     this.name = name;
 60 |     this.room = room;
 61 |     this.message = message;
 62 |   }
 63 | 
 64 |   @Override
 65 |   public MessageType getType() {
 66 |     return type;
 67 |   }
 68 | 
 69 |   /**
 70 |    * Returns the name of the owner of this message.
 71 |    *
 72 |    * @return the name of the owner of this message.
 73 |    */
 74 |   public String getName() {
 75 |     return name;
 76 |   }
 77 | 
 78 |   /**
 79 |    * Returns the contents of this message.
 80 |    *
 81 |    * @return the contents of this message.
 82 |    */
 83 |   public String getMessage() {
 84 |     return message;
 85 |   }
 86 | 
 87 |   /**
 88 |    * Returns a JSON object that will be sent to the clients.
 89 |    *
 90 |    * If the type of this message is {@code MessageType.PROPAGATE}, the return value will be the
 91 |    * serialized form of the <strong>wrapped message</strong>.
 92 |    *
 93 |    * @param gson a Gson object for serializing this message.
 94 |    * @return a JSON object that will be sent to the clients.
 95 |    */
 96 |   @Override
 97 |   public String toJson(Gson gson) {
 98 |     if (type.equals(MessageType.PROPAGATE)) {
 99 |       return message;
100 |     } else {
101 |       return gson.toJson(this);
102 |     }
103 |   }
104 | 
105 |   @Override
106 |   public boolean shouldSendTo(String room) {
107 |     return this.room.equals(room);
108 |   }
109 | 
110 |   @Override
111 |   public String getRoom() {
112 |     return room;
113 |   }
114 | }
115 | 


--------------------------------------------------------------------------------
/pom.xml:
--------------------------------------------------------------------------------
  1 | <?xml version="1.0" encoding="UTF-8"?>
  2 | <!--
  3 |   ~ Copyright (c) 2013 Google Inc. All Rights Reserved.
  4 |   ~
  5 |   ~ Licensed under the Apache License, Version 2.0 (the "License"); you
  6 |   ~ may not use this file except in compliance with the License. You may
  7 |   ~ obtain a copy of the License at
  8 |   ~
  9 |   ~     http://www.apache.org/licenses/LICENSE-2.0
 10 |   ~
 11 |   ~ Unless required by applicable law or agreed to in writing, software
 12 |   ~ distributed under the License is distributed on an "AS IS" BASIS,
 13 |   ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 14 |   ~ implied. See the License for the specific language governing
 15 |   ~ permissions and limitations under the License.
 16 |   -->
 17 | 
 18 | <project xmlns="http://maven.apache.org/POM/4.0.0"
 19 |          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 20 |          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 21 | 
 22 |   <modelVersion>4.0.0</modelVersion>
 23 |   <packaging>war</packaging>
 24 |   <version>1.0-SNAPSHOT</version>
 25 | 
 26 |   <groupId>com.google.appengine.demos</groupId>
 27 |   <artifactId>websocketchat</artifactId>
 28 | 
 29 |   <properties>
 30 |     <appengine.app.version>chat</appengine.app.version>
 31 |     <appengine.target.version>1.9.28</appengine.target.version>
 32 |     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 33 |   </properties>
 34 | 
 35 |   <dependencies>
 36 |     <!-- Compile/runtime dependencies -->
 37 |     <dependency>
 38 |       <groupId>com.google.appengine</groupId>
 39 |       <artifactId>appengine-api-1.0-sdk</artifactId>
 40 |       <version>${appengine.target.version}</version>
 41 |     </dependency>
 42 |     <dependency>
 43 |       <groupId>javax.servlet</groupId>
 44 |       <artifactId>servlet-api</artifactId>
 45 |       <version>2.5</version>
 46 |       <scope>provided</scope>
 47 |     </dependency>
 48 |     <dependency>
 49 |       <groupId>jstl</groupId>
 50 |       <artifactId>jstl</artifactId>
 51 |       <version>1.2</version>
 52 |     </dependency>
 53 |     <dependency>
 54 |       <groupId>org.java-websocket</groupId>
 55 |       <artifactId>Java-WebSocket</artifactId>
 56 |       <version>1.3.0</version>
 57 |     </dependency>
 58 |     <dependency>
 59 |       <groupId>com.google.code.gson</groupId>
 60 |       <artifactId>gson</artifactId>
 61 |       <version>2.3.1</version>
 62 |     </dependency>
 63 |     <dependency>
 64 |       <groupId>com.googlecode.objectify</groupId>
 65 |       <artifactId>objectify</artifactId>
 66 |       <version>4.0b2</version>
 67 |     </dependency>
 68 |     <dependency>
 69 |       <groupId>com.google.guava</groupId>
 70 |       <artifactId>guava</artifactId>
 71 |       <version>18.0</version>
 72 |     </dependency>
 73 | 
 74 |     <!-- Test Dependencies -->
 75 |     <dependency>
 76 |       <groupId>junit</groupId>
 77 |       <artifactId>junit</artifactId>
 78 |       <version>4.12</version>
 79 |       <scope>test</scope>
 80 |     </dependency>
 81 |     <dependency>
 82 |       <groupId>org.mockito</groupId>
 83 |       <artifactId>mockito-all</artifactId>
 84 |       <version>1.10.19</version>
 85 |       <scope>test</scope>
 86 |     </dependency>
 87 |     <dependency>
 88 |       <groupId>com.google.appengine</groupId>
 89 |       <artifactId>appengine-testing</artifactId>
 90 |       <version>${appengine.target.version}</version>
 91 |       <scope>test</scope>
 92 |     </dependency>
 93 |     <dependency>
 94 |       <groupId>com.google.appengine</groupId>
 95 |       <artifactId>appengine-api-stubs</artifactId>
 96 |       <version>${appengine.target.version}</version>
 97 |       <scope>test</scope>
 98 |     </dependency>
 99 |   </dependencies>
100 | 
101 |   <build>
102 |     <plugins>
103 |       <plugin>
104 |         <groupId>org.apache.maven.plugins</groupId>
105 |         <artifactId>maven-compiler-plugin</artifactId>
106 |          <version>2.5.1</version>
107 |        <configuration>
108 |           <source>1.7</source>
109 |           <target>1.7</target>
110 |         </configuration>
111 |       </plugin>
112 | 
113 |       <plugin>
114 |         <groupId>org.apache.maven.plugins</groupId>
115 |         <artifactId>maven-war-plugin</artifactId>
116 |         <version>2.6</version>
117 |         <configuration>
118 |           <archiveClasses>true</archiveClasses>
119 |           <webResources>
120 |             <!-- in order to interpolate version from pom into appengine-web.xml -->
121 |             <resource>
122 |               <directory>${basedir}/src/main/webapp/WEB-INF</directory>
123 |               <filtering>true</filtering>
124 |               <targetPath>WEB-INF</targetPath>
125 |             </resource>
126 |           </webResources>
127 |         </configuration>
128 |       </plugin>
129 | 
130 |       <plugin>
131 |         <groupId>com.google.appengine</groupId>
132 |         <artifactId>gcloud-maven-plugin</artifactId>
133 |         <version>2.0.9.88.v20151125</version>
134 |       </plugin>
135 |     </plugins>
136 |   </build>
137 | 
138 | </project>
139 | 


--------------------------------------------------------------------------------
/src/main/java/com/google/appengine/demos/websocketchat/server/MetaInfoManager.java:
--------------------------------------------------------------------------------
  1 | /*
  2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
  3 |  *
  4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
  5 |  * may not use this file except in compliance with the License. You may
  6 |  * obtain a copy of the License at
  7 |  *
  8 |  *     http://www.apache.org/licenses/LICENSE-2.0
  9 |  *
 10 |  * Unless required by applicable law or agreed to in writing, software
 11 |  * distributed under the License is distributed on an "AS IS" BASIS,
 12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 13 |  * implied. See the License for the specific language governing
 14 |  * permissions and limitations under the License.
 15 |  */
 16 | 
 17 | package com.google.appengine.demos.websocketchat.server;
 18 | 
 19 | import com.google.common.collect.ImmutableSet;
 20 | import org.java_websocket.WebSocket;
 21 | 
 22 | import java.util.Map;
 23 | import java.util.Set;
 24 | import java.util.TreeSet;
 25 | import java.util.concurrent.ConcurrentHashMap;
 26 | import java.util.concurrent.ConcurrentMap;
 27 | 
 28 | /**
 29 |  * A class that manages connections from the clients.
 30 |  */
 31 | public class MetaInfoManager {
 32 | 
 33 |   /**
 34 |    * A class that holds the name of the participant and the name of the chat room.
 35 |    */
 36 |   public class ConnectionInfo {
 37 | 
 38 |     private String name;
 39 | 
 40 |     private String room;
 41 | 
 42 |     /**
 43 |      * Creates a ConnectionInfo instance with the given name and room.
 44 |      *
 45 |      * @param name a name of the participant.
 46 |      * @param room a name of the chat room.
 47 |      */
 48 |     ConnectionInfo(String name, String room) {
 49 |       this.name = name;
 50 |       this.room = room;
 51 |     }
 52 | 
 53 |     /**
 54 |      * Returns a name of the participant.
 55 |      *
 56 |      * @return a name of the participant.
 57 |      */
 58 |     public String getName() {
 59 |       return name;
 60 |     }
 61 | 
 62 |     /**
 63 |      * Returns a name of the chat room.
 64 |      *
 65 |      * @return a name of the chat room.
 66 |      */
 67 |     public String getRoom() {
 68 |       return room;
 69 |     }
 70 |   }
 71 | 
 72 |   private static final Set<String> EMPTY_PARTICIPANT_SET = ImmutableSet.of();
 73 | 
 74 |   private static String createIdFromConnection(WebSocket connection) {
 75 |     return connection.getRemoteSocketAddress().getAddress().getHostAddress() + ":"
 76 |         + connection.getRemoteSocketAddress().getPort();
 77 |   }
 78 | 
 79 |   private Map<String, ConnectionInfo> connectionMap;
 80 | 
 81 |   private Map<String, Set<String>> participantMap;
 82 | 
 83 |   /**
 84 |    * Creates a MetaInfoManager with the initialized map objects.
 85 |    */
 86 |   public MetaInfoManager() {
 87 |     connectionMap = new ConcurrentHashMap<>();
 88 |     participantMap = new ConcurrentHashMap<>();
 89 |   }
 90 | 
 91 |   /**
 92 |    * Returns a set of the names of the participants in a given chat room.
 93 |    *
 94 |    * @param room a name of the chat room.
 95 |    * @return a set of the names of the participants in a given chat room.
 96 |    */
 97 |   public Set<String> getParticipantList(String room) {
 98 |     if (participantMap.containsKey(room)) {
 99 |       return participantMap.get(room);
100 |     } else {
101 |       return EMPTY_PARTICIPANT_SET;
102 |     }
103 |   }
104 | 
105 |   /**
106 |    * Adds a map entry to the participantMap property with a connection identifier as the key and
107 |    * ConnectionInfo with the given name and room as the value.
108 |    *
109 |    * @param connection a websocket connection object.
110 |    * @param name a name of the participant.
111 |    * @param room a name of the chatroom.
112 |    */
113 |   public void addConnection(WebSocket connection, String name, String room) {
114 |     connectionMap.put(createIdFromConnection(connection), new ConnectionInfo(name, room));
115 |     if (! participantMap.containsKey(room)) {
116 |       participantMap.put(room, new TreeSet<String>());
117 |     }
118 |     participantMap.get(room).add(name);
119 |   }
120 | 
121 |   /**
122 |    * Returns a ConnectionInfo object corresponding to a given websocket connection.
123 |    * @param connection a websocket connection object.
124 |    * @return a ConnectionInfo object corresponding to a given websocket connection.
125 |    */
126 |   public ConnectionInfo getConnectionInfo(WebSocket connection) {
127 |     return connectionMap.get(createIdFromConnection(connection));
128 |   }
129 | 
130 |   /**
131 |    * Removes a ConnectionInfo associated to a given websocket connection.
132 |    *
133 |    * @param connection a websocket connection object.
134 |    */
135 |   public void removeConnection(WebSocket connection) {
136 |     ConnectionInfo connectionInfo = getConnectionInfo(connection);
137 |     if (participantMap.containsKey(connectionInfo.getRoom())) {
138 |       participantMap.get(connectionInfo.getRoom()).remove(connectionInfo.getName());
139 |     }
140 |     connectionMap.remove(createIdFromConnection(connection));
141 |   }
142 | }
143 | 


--------------------------------------------------------------------------------
/src/main/java/com/google/appengine/demos/websocketchat/domain/ChatRoomParticipants.java:
--------------------------------------------------------------------------------
  1 | /*
  2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
  3 |  *
  4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
  5 |  * may not use this file except in compliance with the License. You may
  6 |  * obtain a copy of the License at
  7 |  *
  8 |  *     http://www.apache.org/licenses/LICENSE-2.0
  9 |  *
 10 |  * Unless required by applicable law or agreed to in writing, software
 11 |  * distributed under the License is distributed on an "AS IS" BASIS,
 12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 13 |  * implied. See the License for the specific language governing
 14 |  * permissions and limitations under the License.
 15 |  */
 16 | 
 17 | package com.google.appengine.demos.websocketchat.domain;
 18 | 
 19 | import com.googlecode.objectify.Key;
 20 | import com.googlecode.objectify.annotation.Entity;
 21 | import com.googlecode.objectify.annotation.Id;
 22 | import com.googlecode.objectify.annotation.Parent;
 23 | 
 24 | import java.util.ArrayList;
 25 | import java.util.Collection;
 26 | import java.util.List;
 27 | import java.util.Set;
 28 | import java.util.TreeSet;
 29 | import java.util.logging.Logger;
 30 | 
 31 | import static com.googlecode.objectify.ObjectifyService.ofy;
 32 | 
 33 | /**
 34 |  * An entity class which holds a list of participants for a chat room within a single server node.
 35 |  *
 36 |  * <p>The parentKey parameter should be set with the name of the chat room as the key name. This
 37 |  * is forced by only providing a single public constructor which has {@code String room} as the
 38 |  * first parameter.
 39 |  * </p>
 40 |  */
 41 | @Entity
 42 | public class ChatRoomParticipants {
 43 | 
 44 |   private static final Logger LOG = Logger.getLogger(ChatRoomParticipants.class.getName());
 45 | 
 46 |   /* parentKey has a room name as the key name. */
 47 |   @Parent
 48 |   private Key<ChatRoomParticipants> parentKey;
 49 | 
 50 |   @Id
 51 |   private String serverNode;
 52 | 
 53 |   private Set<String> participants;
 54 | 
 55 |   /* Objectify needs the default constructor. */
 56 |   private ChatRoomParticipants() {}
 57 | 
 58 |   /**
 59 |    * Returns the global list of participants of the given chat room.
 60 |    *
 61 |    * <p>This method aggregates the participants list among multiple servers and return the
 62 |    * global list of the given chat room.</p>
 63 |    *
 64 |    * @param room a name of the chat room.
 65 |    * @return the global list of participants of the given chat room.
 66 |    */
 67 |   public static Set<String> getParticipants(String room) {
 68 |     List<Key<WebSocketServerNode>> serverNodeKeyList = ofy().load()
 69 |         .type(WebSocketServerNode.class).ancestor(WebSocketServerNode.getRootKey()).keys().list();
 70 |     List<Key<ChatRoomParticipants>> chatRoomParticipantsKeys = new ArrayList<>();
 71 |     Key<ChatRoomParticipants> parentKey = Key.create(ChatRoomParticipants.class, room);
 72 |     for (Key<WebSocketServerNode> serverNodeKey: serverNodeKeyList) {
 73 |       Key<ChatRoomParticipants> chatRoomParticipantsKey =
 74 |           Key.create(parentKey, ChatRoomParticipants.class, serverNodeKey.getName());
 75 |       LOG.info("chatRoomParticipantsKey: " + chatRoomParticipantsKey);
 76 |       chatRoomParticipantsKeys.add(chatRoomParticipantsKey);
 77 |     }
 78 |     Collection<ChatRoomParticipants> chatRoomParticipantsCollection =
 79 |         ofy().transaction().load().keys(chatRoomParticipantsKeys).values();
 80 |     Set<String> participantSet = new TreeSet<>();
 81 |     for (ChatRoomParticipants participants: chatRoomParticipantsCollection) {
 82 |       LOG.info("Adding " + participants.getParticipants());
 83 |       participantSet.addAll(participants.getParticipants());
 84 |     }
 85 |     return participantSet;
 86 |   }
 87 | 
 88 |   /**
 89 |    * Creates an entity representing the list of the participants in a chat room within a single
 90 |    * server node.
 91 |    *
 92 |    * @param room a name of the chat room.
 93 |    * @param serverNode an identifier of a single server node, in the form of websocket URL,
 94 |    *                   e.x. "ws://173.255.112.201:65080/".
 95 |    * @param participants a set of participants in the given chat room within a single server node.
 96 |    */
 97 |   public ChatRoomParticipants(String room, String serverNode, Set<String> participants) {
 98 |     this.parentKey = Key.create(ChatRoomParticipants.class, room);
 99 |     this.serverNode = serverNode;
100 |     this.participants = new TreeSet<>(participants);
101 |   }
102 | 
103 |   /**
104 |    * Returns the list of the participants in this entity.
105 |    *
106 |    * @return the list of the participants in the given chat room within a single server node.
107 |    */
108 |   public Set<String> getParticipants() {
109 |     if (participants == null) {
110 |       return new TreeSet<>();
111 |     }
112 |     return new TreeSet<>(participants);
113 |   }
114 | 
115 |   /**
116 |    * Returns the objectify key object representing this entity.
117 |    *
118 |    * @return the objectify key object representing this entity.
119 |    */
120 |   public Key<ChatRoomParticipants> getKey() {
121 |     return Key.create(this.parentKey, ChatRoomParticipants.class, serverNode);
122 |   }
123 | }
124 | 


--------------------------------------------------------------------------------
/src/main/webapp/chat.jsp:
--------------------------------------------------------------------------------
  1 | <%@ page contentType="text/html;charset=UTF-8" language="java" %>
  2 | <%@ page import="com.google.appengine.api.users.User" %>
  3 | <%@ page import="com.google.appengine.api.users.UserService" %>
  4 | <%@ page import="com.google.appengine.api.users.UserServiceFactory" %>
  5 | <%@ page import="com.google.appengine.demos.websocketchat.server.ChatSocketServer" %>
  6 | 
  7 | <%--
  8 |   ~ Copyright (c) 2013 Google Inc. All Rights Reserved.
  9 |   ~
 10 |   ~ Licensed under the Apache License, Version 2.0 (the "License"); you
 11 |   ~ may not use this file except in compliance with the License. You may
 12 |   ~ obtain a copy of the License at
 13 |   ~
 14 |   ~     http://www.apache.org/licenses/LICENSE-2.0
 15 |   ~
 16 |   ~ Unless required by applicable law or agreed to in writing, software
 17 |   ~ distributed under the License is distributed on an "AS IS" BASIS,
 18 |   ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 19 |   ~ implied. See the License for the specific language governing
 20 |   ~ permissions and limitations under the License.
 21 |   --%>
 22 | 
 23 | <%
 24 |   UserService userService = UserServiceFactory.getUserService();
 25 |   User user = userService.getCurrentUser();
 26 |   String webSocketURL = ChatSocketServer.ChatServerBridge.getInstance().getWebSocketURL();
 27 | %>
 28 | 
 29 | <!DOCTYPE html>
 30 | 
 31 | <html>
 32 | 
 33 | <head>
 34 |   <link href='//fonts.googleapis.com/css?family=Marmelad' rel='stylesheet' type='text/css'>
 35 |   <link type="text/css" rel="stylesheet" href="/stylesheets/main.css"/>
 36 |   <script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.1/jquery.min.js"></script>
 37 | </head>
 38 | 
 39 | <body>
 40 | <div id="container">
 41 | 
 42 |   <div id="header">
 43 |     <h2>WebSocket chat on App Engine VM Runtime</h2>
 44 |     Name: <input id="name" value="<%= user.getNickname() %>">
 45 |     Room: <input id="room" value="#vmruntime">
 46 |     <input type="button" id="enter" value="Enter">
 47 |     <input type="button" id="leave" value="Leave" style="display: none;">
 48 | 
 49 |     <form id="chatForm">
 50 |       Message: <input id="message" size="50" autocomplete="off">
 51 |     </form>
 52 |   </div>
 53 | 
 54 |   <div id="participants">Participants:</div>
 55 |   <div id="messages"></div>
 56 | </div>
 57 | 
 58 | </body>
 59 | <script>
 60 |   var wschat = {
 61 |     connection: null,
 62 |     should_be_connected: false
 63 |   }
 64 | 
 65 |   function updateParticipantsList(message) {
 66 |     var participants = message.participantSet;
 67 |     $('#participants').children().remove();
 68 |     for (var i = 0; i < participants.length; i++) {
 69 |       $('#participants').append('<p>' + $('<div/>').text(participants[i]).html());
 70 |     }
 71 |   }
 72 | 
 73 |   function resetDOMsOnClose() {
 74 |     $('#participants').children().remove();
 75 |     $('#enter').show();
 76 |     $('#leave').hide();
 77 |     $('#name').attr('readonly', false);
 78 |     $('#room').attr('readonly', false);
 79 |   }
 80 | 
 81 |   function closeWebSocketConnection() {
 82 |     wschat.should_be_connected = false;
 83 |     wschat.connection.close();
 84 |     resetDOMsOnClose();
 85 |   }
 86 | 
 87 |   function openWebSocketConnection() {
 88 |     $('#enter').hide();
 89 |     $('#leave').show();
 90 |     $('#name').attr('readonly', true);
 91 |     $('#room').attr('readonly', true);
 92 |     wschat.connection = new WebSocket('<%= webSocketURL %>');
 93 |     wschat.connection.onopen = function () {
 94 |       console.log('Websocket opened');
 95 |       var messageBody = {
 96 |         type: 'ENTER',
 97 |         name: $('#name').val(),
 98 |         room: $('#room').val(),
 99 |         message: ''
100 |       }
101 |       wschat.connection.send(JSON.stringify(messageBody));
102 |     }
103 |     wschat.connection.onerror = function (error) {
104 |       console.log('Error detected: ' + error);
105 |       closeWebSocketConnection();
106 |     }
107 |     wschat.connection.onmessage = function (e) {
108 |       var server_message = e.data;
109 |       console.log('Message received: ' + server_message);
110 |       var message = JSON.parse(server_message);
111 |       if (message.type == 'PARTICIPANTS') {
112 |         updateParticipantsList(message);
113 |         return;
114 |       }
115 |       if (message.type == 'SYSTEM') {
116 |         $('#messages').prepend('<p class="system">' + $('<div/>').text(message.message).html());
117 |         $('#name').val(message.name);
118 |         return;
119 |       }
120 |       var text_message;
121 |       if (message.type == 'MESSAGE') {
122 |         text_message = message.name + ': ' + message.message;
123 |       } else if (message.type == 'ENTER') {
124 |         text_message = message.name + ' entered ' + message.room;
125 |       } else if (message.type == 'LEAVE') {
126 |         text_message = message.name + ' left ' + message.room;
127 |       }
128 |       $('#messages').prepend('<p>' + $('<div/>').text(text_message).html());
129 |     }
130 |     wschat.connection.onclose = function () {
131 |       console.log('Connection closed.');
132 |       resetDOMsOnClose();
133 |     }
134 |     wschat.should_be_connected = true;
135 |   }
136 |   $(document).ready(function () {
137 |     $('#enter').click(function(e) {
138 |       openWebSocketConnection();
139 |     });
140 |     $('#leave').click(function(e) {
141 |       closeWebSocketConnection();
142 |     });
143 |     $('#chatForm').submit(function(e) {
144 |       e.preventDefault();
145 |       if (wschat.connection === undefined ||
146 |           wschat.should_be_connected === false) {
147 |         window.alert('Please enter a room before posting.');
148 |         return false;
149 |       }
150 |       var messageBody = {
151 |         type: 'MESSAGE',
152 |         name: $('#name').val(),
153 |         room: $('#room').val(),
154 |         message: $('#message').val()
155 |       }
156 |       wschat.connection.send(JSON.stringify(messageBody));
157 |       $('#message').val('');
158 |       return false;
159 |     });
160 |   });
161 | 
162 | </script>
163 | </html>
164 | 


--------------------------------------------------------------------------------
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--------------------------------------------------------------------------------
/src/main/java/com/google/appengine/demos/websocketchat/server/ChatSocketServer.java:
--------------------------------------------------------------------------------
  1 | /*
  2 |  * Copyright (c) 2013 Google Inc. All Rights Reserved.
  3 |  *
  4 |  * Licensed under the Apache License, Version 2.0 (the "License"); you
  5 |  * may not use this file except in compliance with the License. You may
  6 |  * obtain a copy of the License at
  7 |  *
  8 |  *     http://www.apache.org/licenses/LICENSE-2.0
  9 |  *
 10 |  * Unless required by applicable law or agreed to in writing, software
 11 |  * distributed under the License is distributed on an "AS IS" BASIS,
 12 |  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 13 |  * implied. See the License for the specific language governing
 14 |  * permissions and limitations under the License.
 15 |  */
 16 | 
 17 | package com.google.appengine.demos.websocketchat.server;
 18 | 
 19 | import java.io.BufferedReader;
 20 | import java.io.IOException;
 21 | import java.io.InputStreamReader;
 22 | import java.net.HttpURLConnection;
 23 | import java.net.InetSocketAddress;
 24 | import java.net.URI;
 25 | import java.net.URISyntaxException;
 26 | import java.net.URL;
 27 | import java.util.Collection;
 28 | import java.util.List;
 29 | import java.util.Map;
 30 | import java.util.Set;
 31 | import java.util.concurrent.ConcurrentHashMap;
 32 | import java.util.concurrent.ConcurrentLinkedQueue;
 33 | import java.util.concurrent.CopyOnWriteArrayList;
 34 | import java.util.logging.Logger;
 35 | 
 36 | import com.google.appengine.api.NamespaceManager;
 37 | import com.google.appengine.api.ThreadManager;
 38 | import com.google.appengine.api.utils.SystemProperty;
 39 | import com.google.appengine.demos.websocketchat.domain.ChatRoomParticipants;
 40 | import com.google.appengine.demos.websocketchat.domain.WebSocketServerNode;
 41 | import com.google.appengine.demos.websocketchat.message.ChatMessage;
 42 | import com.google.appengine.demos.websocketchat.message.OutgoingMessage;
 43 | import com.google.appengine.demos.websocketchat.message.ParticipantListMessage;
 44 | import com.google.apphosting.api.ApiProxy;
 45 | import com.google.common.base.Throwables;
 46 | import com.google.gson.Gson;
 47 | import com.googlecode.objectify.Key;
 48 | import org.java_websocket.WebSocket;
 49 | import org.java_websocket.client.WebSocketClient;
 50 | import org.java_websocket.handshake.ClientHandshake;
 51 | import org.java_websocket.handshake.ServerHandshake;
 52 | import org.java_websocket.server.WebSocketServer;
 53 | 
 54 | import static com.googlecode.objectify.ObjectifyService.ofy;
 55 | 
 56 | /**
 57 |  * A simple WebSocketServerNode implementation. Keeps track of a "websocketchat".
 58 |  */
 59 | public class ChatSocketServer extends WebSocketServer {
 60 | 
 61 |   private static final Logger LOG = Logger.getLogger(ChatSocketServer.class.getName());
 62 | 
 63 |   private static final int DEFAULT_PORT = 65080;
 64 | 
 65 |   private static final Gson GSON = new Gson();
 66 | 
 67 |   private static final String NETWORK_INTERFACE_METADATA_URL =
 68 |       "http://metadata/computeMetadata/v1beta1/instance/network-interfaces/0/access-configs/0/" +
 69 |           "external-ip";
 70 | 
 71 |   private final MetaInfoManager metaInfoManager;
 72 | 
 73 |   private ConcurrentLinkedQueue<String> updateAndSendParticipantListQueue;
 74 | 
 75 |   private ConcurrentLinkedQueue<OutgoingMessage> propagateQueue;
 76 | 
 77 |   private String hostname;
 78 | 
 79 |   private String getHostname() throws IOException {
 80 |     if (hostname == null) {
 81 |       if (SystemProperty.environment.value().equals(SystemProperty.Environment.Value.Production)) {
 82 |         URL url = new URL(NETWORK_INTERFACE_METADATA_URL);
 83 |         HttpURLConnection httpUrlConnection = (HttpURLConnection) url.openConnection();
 84 |         BufferedReader reader = new BufferedReader(
 85 |             new InputStreamReader(httpUrlConnection.getInputStream()));
 86 |         String result, line = reader.readLine();
 87 |         result = line;
 88 |         while ((line = reader.readLine()) != null) {
 89 |           result += line;
 90 |         }
 91 |         hostname = result;
 92 |       } else {
 93 |         hostname = "localhost";
 94 |       }
 95 |     }
 96 |     return hostname;
 97 |   }
 98 | 
 99 |   /**
100 |    * Returns a Websocket URL of this server.
101 |    *
102 |    * @return a Websocket URL of this server.
103 |    * @throws IOException when failed to get the external IP address from the metadata server.
104 |    */
105 |   public String getWebSocketURL() throws IOException {
106 |     return "ws://" + getHostname() + ":" + this.getPort() + "/";
107 |   }
108 | 
109 |   /**
110 |    * A class that runs in another thread and becomes a bridge between App Engine and the
111 |    * websocket server.
112 |    */
113 |   public static class ChatServerBridge implements Runnable {
114 | 
115 |     private ChatSocketServer chatSocketServer;
116 | 
117 |     private Thread watcherThread;
118 | 
119 |     private String namespace;
120 | 
121 |     private static ChatServerBridge chatServerBridge;
122 | 
123 |     private CopyOnWriteArrayList<Key<ChatRoomParticipants>> chatRoomParticipantsKeyList;
124 | 
125 |     private ApiProxy.Environment backgroundEnvironment;
126 | 
127 |     private ChatServerBridge() {
128 |       namespace = NamespaceManager.get();
129 |       chatRoomParticipantsKeyList = new CopyOnWriteArrayList<>();
130 |     }
131 | 
132 |     /**
133 |      * Returns a singleton instance of this class.
134 |      *
135 |      * @return a singleton instance of this class.
136 |      */
137 |     public static ChatServerBridge getInstance() {
138 |       if (chatServerBridge == null) {
139 |         chatServerBridge = new ChatServerBridge();
140 |       }
141 |       return chatServerBridge;
142 |     }
143 | 
144 |     private void registerWebSocketServerNode() throws IOException {
145 |       WebSocketServerNode webSocketServerNode = new WebSocketServerNode(
146 |           chatSocketServer.getWebSocketURL());
147 |       ofy().save().entity(webSocketServerNode).now();
148 |     }
149 | 
150 |     private void removeWebSocketServerNode() throws IOException {
151 |       Key<WebSocketServerNode> key = WebSocketServerNode.getKeyFromWebSocketUrl(
152 |           chatSocketServer.getWebSocketURL());
153 |       ofy().delete().key(key).now();
154 |     }
155 | 
156 |     protected ApiProxy.Environment getBackgroundEnvironment() {
157 |       return backgroundEnvironment;
158 |     }
159 | 
160 |     /**
161 |      * Starts the websocket server, registers necessary information and then starts the bridge
162 |      * thread.
163 |      */
164 |     public void start() {
165 |       if (chatSocketServer != null) {
166 |         throw new IllegalStateException("We already have a chatSocketServer.");
167 |       }
168 |       chatSocketServer = new ChatSocketServer(DEFAULT_PORT);
169 |       chatSocketServer.start();
170 |       LOG.info("Server started on port: " + chatSocketServer.getPort());
171 |       try {
172 |         registerWebSocketServerNode();
173 |       } catch (IOException e) {
174 |         LOG.warning(Throwables.getStackTraceAsString(e));
175 |       }
176 |       ThreadManager.createBackgroundThread(this).start();
177 |     }
178 | 
179 |     /**
180 |      * Stops the websocket server, cleans up some info, and then stop the main bridge thread.
181 |      */
182 |     public void stop() {
183 |       try {
184 |         removeWebSocketServerNode();
185 |         chatSocketServer.stop();
186 |         watcherThread.interrupt();
187 |         watcherThread.join();
188 |         watcherThread = null;
189 |         // delete participant list in the datastore
190 |         ofy().delete().keys(chatRoomParticipantsKeyList).now();
191 |         // initialize variables
192 |         chatRoomParticipantsKeyList = new CopyOnWriteArrayList<>();
193 |         chatSocketServer = null;
194 |       } catch (IOException|InterruptedException e) {
195 |         LOG.warning(Throwables.getStackTraceAsString(e));
196 |       }
197 |     }
198 | 
199 |     /**
200 |      * Pops a name of a chat room from the updateAndSendParticipantListQueue and update the
201 |      * participant list in the datastore, then creates the global list of the given chat room and
202 |      * distribute it to the clients who is participating to that chat room.
203 |      *
204 |      * @throws IOException
205 |      */
206 |     private void updateParticipantListAndDistribute() throws IOException {
207 |       if (! chatSocketServer.updateAndSendParticipantListQueue.isEmpty()) {
208 |         // Update the participant list in the datastore
209 |         String room = chatSocketServer.updateAndSendParticipantListQueue.remove();
210 |         ChatRoomParticipants chatRoomParticipants = new ChatRoomParticipants(room,
211 |             chatSocketServer.getWebSocketURL(),
212 |             chatSocketServer.metaInfoManager.getParticipantList(room));
213 |         ofy().save().entity(chatRoomParticipants).now();
214 |         chatRoomParticipantsKeyList.add(chatRoomParticipants.getKey());
215 |         // Retrieve the full participant list in the room and distribute it
216 |         Set<String> participantSet = ChatRoomParticipants.getParticipants(room);
217 |         ParticipantListMessage participantListMessage = new ParticipantListMessage(room,
218 |             participantSet);
219 |         chatSocketServer.sendToClients(participantListMessage);
220 |       }
221 |     }
222 | 
223 |     /**
224 |      * Propagate a message popped from the propagateQueue to other active server nodes.
225 |      *
226 |      * @throws IOException
227 |      */
228 |     private void propagateOneMessage() throws IOException {
229 |       if (! chatSocketServer.propagateQueue.isEmpty()) {
230 |         // handle message propagation between the server nodes.
231 |         OutgoingMessage message = chatSocketServer.propagateQueue.remove();
232 |         LOG.info("Handling a propagate message: " + message.toJson(GSON));
233 |         Key<WebSocketServerNode> parentKey = WebSocketServerNode.getRootKey();
234 |         List<Key<WebSocketServerNode>> serverKeys = ofy().load()
235 |             .type(WebSocketServerNode.class).ancestor(parentKey).keys().list();
236 |         final ChatMessage propagateMessage =
237 |             ChatMessage.createPropagateMessage(message, GSON);
238 |         for (Key<WebSocketServerNode> key: serverKeys) {
239 |           LOG.info("Server: " + key.getName());
240 |           if (! key.getName().equals(chatSocketServer.getWebSocketURL())) {
241 |             // Send a propagate message
242 |             LOG.info("Trying to send a message to the server: " + key.getName());
243 |             try {
244 |               final WebSocketClient chatClient = new WebSocketClient(new URI(key.getName())) {
245 |                 @Override
246 |                 public void onOpen(ServerHandshake handshakedata) {
247 |                   // Send propagateMessage itself.
248 |                   this.send(GSON.toJson(propagateMessage));
249 |                   this.close();
250 |                 }
251 | 
252 |                 @Override
253 |                 public void onMessage(String message) {
254 |                   LOG.info("Message received: " + message);
255 |                 }
256 | 
257 |                 @Override
258 |                 public void onClose(int code, String reason, boolean remote) {
259 |                   LOG.info("Connection closed.");
260 |                 }
261 | 
262 |                 @Override
263 |                 public void onError(Exception ex) {
264 |                   LOG.warning(Throwables.getStackTraceAsString(ex));
265 |                 }
266 |               };
267 |               chatClient.connect();
268 |             } catch (URISyntaxException e) {
269 |               LOG.warning(Throwables.getStackTraceAsString(e));
270 |             }
271 |           }
272 |         }
273 |       }
274 |     }
275 | 
276 |     /**
277 |      * A main loop of this bridge thread.
278 |      *
279 |      * <p>The chat server requests us the following 2 things.</p>
280 |      * <ul>
281 |      *   <li>Update and distribute the participant list in a particular chat room.</li>
282 |      *   <li>Propagate a message to other active server nodes.</li>
283 |      * </ul>
284 |      * <p>This thread watches the 2 queues on the ChatSocketServer instance,
285 |      * and handles those requests in the main loop.</p>
286 |      * <p>If this loop becomes the performance bottleneck, distribute these work loads into
287 |      * multiple thread worker.</p>
288 |      */
289 |     public void run() {
290 |       if (watcherThread != null) {
291 |         throw new IllegalStateException("A watcherThread already exists.");
292 |       }
293 |       watcherThread = Thread.currentThread();
294 |       LOG.info("Namespace is set to " + namespace + " in thread " + watcherThread.toString());
295 |       NamespaceManager.set(namespace);
296 |       // Store the environment for later use.
297 |       backgroundEnvironment = ApiProxy.getCurrentEnvironment();
298 | 
299 |       while (true) {
300 |         if (Thread.currentThread().isInterrupted()) {
301 |           LOG.info("ChatServerBridge is stopping.");
302 |           return;
303 |         } else {
304 |           try {
305 |             updateParticipantListAndDistribute();
306 |             propagateOneMessage();
307 |             Thread.sleep(100);
308 |           } catch (InterruptedException e) {
309 |             Thread.currentThread().interrupt();
310 |             break;
311 |           } catch (IOException e) {
312 |             LOG.warning(Throwables.getStackTraceAsString(e));
313 |           }
314 |         }
315 |       }
316 |     }
317 | 
318 |     /**
319 |      * Returns a Websocket URL of the chat server.
320 |      *
321 |      * @return a Websocket URL of the chat server.
322 |      * @throws IOException when failed to get the external IP address from the metadata server.
323 |      */
324 |     public String getWebSocketURL() throws IOException {
325 |       return this.chatSocketServer.getWebSocketURL();
326 |     }
327 |   }
328 | 
329 |   /**
330 |    * Creates a ChatSoccketServer instance with the given network port.
331 |    *
332 |    * @param port a port number on which this chat server will listen.
333 |    */
334 |   public ChatSocketServer(int port) {
335 |     super(new InetSocketAddress(port));
336 |     metaInfoManager = new MetaInfoManager();
337 |     updateAndSendParticipantListQueue = new ConcurrentLinkedQueue<>();
338 |     propagateQueue = new ConcurrentLinkedQueue<>();
339 |   }
340 | 
341 |   /**
342 |    * Records the incoming connection to the log.
343 |    * @param conn a websocket connection object.
344 |    * @param handshake a websocket handshake object.
345 |    */
346 |   @Override
347 |   public void onOpen(WebSocket conn, ClientHandshake handshake) {
348 |     LOG.info(conn.getRemoteSocketAddress().getAddress().getHostAddress() + " entered the room!");
349 |   }
350 | 
351 |   /**
352 |    * Removes a ConnectionInfo object associated with a given websocket connection from the
353 |    * MetaInfoManager.
354 |    *
355 |    * @param conn a websocket connection object.
356 |    * @param code an integer code that you can look up at
357 |    *             {@link org.java_websocket.framing.CloseFrame}.
358 |    * @param reason an additional information.
359 |    * @param remote Returns whether or not the closing of the connection was initiated by the remote
360 |    *               host.
361 |    */
362 |   @Override
363 |   public void onClose(WebSocket conn, int code, String reason, boolean remote) {
364 |     LOG.info(conn + " has left the room!");
365 |     MetaInfoManager.ConnectionInfo connectionInfo = metaInfoManager.getConnectionInfo(conn);
366 |     if (connectionInfo != null) {
367 |       this.sendToClients(new ChatMessage(OutgoingMessage.MessageType.LEAVE,
368 |           connectionInfo.getName(), connectionInfo.getRoom(), null));
369 |       metaInfoManager.removeConnection(conn);
370 |       if (! updateAndSendParticipantListQueue.contains(connectionInfo.getRoom())) {
371 |         updateAndSendParticipantListQueue.add(connectionInfo.getRoom());
372 |       }
373 |     }
374 |   }
375 | 
376 |   /**
377 |    * Handles incoming messages.
378 |    *
379 |    * If the type of the incoming message is MessageType.ENTER, we need to check the username
380 |    * against the current participant list and change the requested name with trailing underscores.
381 |    * Regardless of the type, we invoke sendToClient method with every incoming messages.
382 |    *
383 |    * @param conn a websocket connection object.
384 |    * @param rawMessage a raw message from the clients.
385 |    */
386 |   @Override
387 |   public void onMessage(WebSocket conn, String rawMessage) {
388 |     // TODO: Make it threadsafe
389 |     LOG.info(conn + ": " + rawMessage);
390 |     ApiProxy.setEnvironmentForCurrentThread(
391 |         ChatServerBridge.getInstance().getBackgroundEnvironment());
392 |     ChatMessage message = GSON.fromJson(rawMessage, ChatMessage.class);
393 |     if (message.getType().equals(OutgoingMessage.MessageType.ENTER)) {
394 |       // Check if there's a participant with the same name in the room.
395 |       Set<String> participantSet = ChatRoomParticipants.getParticipants(message.getRoom());
396 |       if (participantSet.contains(message.getName())) {
397 |         // Adding a trailing underscore until the conflict resolves.
398 |         String newName = message.getName() + "_";
399 |         while (participantSet.contains(newName)) {
400 |           newName = newName + "_";
401 |         }
402 |         // New name decided.
403 |         message = new ChatMessage(message.getType(), newName, message.getRoom(),
404 |             message.getMessage());
405 |         ChatMessage systemMessage = new ChatMessage(OutgoingMessage.MessageType.SYSTEM, newName,
406 |             message.getRoom(), "Changed the name to " + newName + ".");
407 |         conn.send(GSON.toJson(systemMessage));
408 |       }
409 |       metaInfoManager.addConnection(conn, message.getName(), message.getRoom());
410 |       if (! updateAndSendParticipantListQueue.contains(message.getRoom())) {
411 |         updateAndSendParticipantListQueue.add(message.getRoom());
412 |       }
413 |     }
414 |     this.sendToClients(message);
415 |   }
416 | 
417 |   /**
418 |    * Just logs the exception.
419 |    * @param conn a websocket connection object.
420 |    * @param ex an exception.
421 |    */
422 |   @Override
423 |   public void onError(WebSocket conn, Exception ex) {
424 |     LOG.warning(Throwables.getStackTraceAsString(ex));
425 |   }
426 | 
427 |   /**
428 |    * Sends <var>message</var> to currently connected WebSocket clients in the same room as the
429 |    * message.
430 |    *
431 |    * @param message An object representing a message to send across the network.
432 |    */
433 |   public void sendToClients(OutgoingMessage message) {
434 |     if (! message.getType().equals(OutgoingMessage.MessageType.PROPAGATE)) {
435 |       propagateQueue.add(message);
436 |     } else {
437 |       ParticipantListMessage participantListMessage = GSON.fromJson(message.toJson(GSON),
438 |           ParticipantListMessage.class);
439 |       if (participantListMessage.getType().equals(OutgoingMessage.MessageType.PARTICIPANTS)) {
440 |         LOG.info("ParticipantList arrived for the room:" + message.getRoom());
441 |       }
442 |     }
443 |     Collection<WebSocket> webSocketConnections = connections();
444 |     synchronized (webSocketConnections) {
445 |       for (WebSocket connection : webSocketConnections) {
446 |         MetaInfoManager.ConnectionInfo info = metaInfoManager.getConnectionInfo(connection);
447 |         if (info != null) {
448 |           if (message.shouldSendTo(info.getRoom())) {
449 |             connection.send(message.toJson(GSON));
450 |           }
451 |         }
452 |       }
453 |     }
454 |   }
455 | }


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