vvakame/ChannelController.java

## appengine-web.xml
<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
    <application>vvakame-hrd</application>
	<version>channel-api-sample</version>

	<static-files>
		<include path="/**.*" />
	</static-files>

	<precompilation-enabled>true</precompilation-enabled>
	<inbound-services>
		<service>channel_presence</service>
	</inbound-services>

	<system-properties>
		<property name="slim3.hotReloading" value="true" />
		<property name="java.util.logging.config.file" value="WEB-INF/classes/logging.properties" />
	</system-properties>
	<sessions-enabled>false</sessions-enabled>
	<threadsafe>true</threadsafe>

</appengine-web-app>

## ChannelController.java
import java.io.PrintWriter;
import java.io.Writer;
import java.util.List;

import org.slim3.controller.Controller;
import org.slim3.controller.Navigation;
import org.slim3.datastore.Datastore;
import org.slim3.repackaged.org.json.JSONObject;
import org.slim3.util.StringUtil;

import com.google.appengine.api.channel.ChannelMessage;
import com.google.appengine.api.channel.ChannelService;
import com.google.appengine.api.channel.ChannelServiceFactory;
import com.google.appengine.api.users.User;
import com.google.appengine.api.users.UserService;
import com.google.appengine.api.users.UserServiceFactory;

public class ChannelController extends Controller {

  @Override
	protected Navigation run() throws Exception {
		response.setCharacterEncoding("UTF-8");
		response.setContentType("application/json");

		UserService userService = UserServiceFactory.getUserService();
		User user = userService.getCurrentUser();
		if (user == null) {
			String loginURL = userService.createLoginURL("/");
			JSONObject jsonObject = new JSONObject();
			jsonObject.put("redirectTo", loginURL);
			Writer writer = new PrintWriter(response.getOutputStream());
			writer.write(jsonObject.toString());
			writer.flush();

			return null;
		}

		{
			ChannelUser channelUser = new ChannelUser();
			channelUser.setKey(Datastore.createKey(ChannelUser.class,
					user.getUserId()));
			channelUser.setUser(user);
			Datastore.put(channelUser);
		}

		if (isGet()) {
			String token = getToken(user.getUserId());
			JSONObject jsonObject = new JSONObject();
			jsonObject.put("userId", user.getUserId());
			jsonObject.put("token", token);
			Writer writer = new PrintWriter(response.getOutputStream());
			writer.write(jsonObject.toString());
			writer.flush();

		} else {
			String message = asString("message");
			if (StringUtil.isEmpty(message)) {
				return null;
			}
			List<ChannelUser> list = Datastore.query(ChannelUser.class)
					.asList();
			for (ChannelUser channelUser : list) {
				sendUpdateToUser(channelUser.getKey().getName(), message);
			}
			response.getOutputStream().write("{}".getBytes());
		}

		return null;
	}

	void sendUpdateToUser(String userId, String message) {
		ChannelService channelService = ChannelServiceFactory
				.getChannelService();
		channelService.sendMessage(new ChannelMessage(userId, message));
	}

	String getToken(String userId) {
		ChannelService channelService = ChannelServiceFactory
				.getChannelService();
		String token = channelService.createChannel(userId);
		return token;
	}
}

## ChannelUser.java
import org.slim3.datastore.Attribute;
import org.slim3.datastore.Model;

import com.google.appengine.api.datastore.Key;
import com.google.appengine.api.users.User;

@Model
public class ChannelUser {

  @Attribute(primaryKey = true)
	Key key;

	User user;

	/**
	 * @return the key
	 */
	public Key getKey() {
		return key;
	}

	/**
	 * @param key
	 *            the key to set
	 */
	public void setKey(Key key) {
		this.key = key;
	}

	/**
	 * @return the user
	 */
	public User getUser() {
		return user;
	}

	/**
	 * @param user
	 *            the user to set
	 */
	public void setUser(User user) {
		this.user = user;
	}
}

## index.html
<html>
<head>
    <meta http-equiv="content-type" content="text/html; charset=utf-8">
    <script src="/_ah/channel/jsapi"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
    <title>Channel API</title>

    <script type="text/javascript">
        var socket;
        $(document).ready(function () {
            $.ajax({
                type:"GET",
                url:"/channel",
                contentType:"application/json",
                dataType:"json",
                data:{},
                success:function (data) {
                    console.log(data);
                    if (data.redirectTo) {
                        window.location = data.redirectTo;
                        return;
                    }

                    var channel = new goog.appengine.Channel(data.token);
                    socket = channel.open();

                    socket.onopen = function () {
                        addText("接続が開始されました。データを送信できます");
                    };
                    socket.onerror = function () {
                        addText("サーバでエラー！");
                    };
                    socket.onclose = function () {
                        addText("接続が正常に終了しました");
                    };
                    socket.onmessage = function (data) {
                        console.log(data);
                        addText(data.data);
                    };

                    addText("あなたのuserIdは" + data.userId + "です。");
                }
            });

            $("#send").on("click", function () {
                $.ajax({
                    type:"POST",
                    url:"/channel",
                    data:{
                        message:$("#message").val()
                    },
                    success:function (data) {
                        console.log(data);
                    }
                });

            });
        });

        function addText(text) {
            console.log(text);
            $("<div>").text(text).appendTo($("#content"));
        }
    </script>
</head>
<body>

<div id="content">
</div>

<input id="message" type="text" value="">
<input id="send" type="button" value="データを送信">

</body>
</html>
	<?xml version="1.0" encoding="utf-8"?>
	<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
	<application>vvakame-hrd</application>
	<version>channel-api-sample</version>

	<static-files>
	<include path="/*." />
	</static-files>

	<precompilation-enabled>true</precompilation-enabled>
	<inbound-services>
	<service>channel_presence</service>
	</inbound-services>

	<system-properties>
	<property name="slim3.hotReloading" value="true" />
	<property name="java.util.logging.config.file" value="WEB-INF/classes/logging.properties" />
	</system-properties>
	<sessions-enabled>false</sessions-enabled>
	<threadsafe>true</threadsafe>

	</appengine-web-app>
	import java.io.PrintWriter;
	import java.io.Writer;
	import java.util.List;

	import org.slim3.controller.Controller;
	import org.slim3.controller.Navigation;
	import org.slim3.datastore.Datastore;
	import org.slim3.repackaged.org.json.JSONObject;
	import org.slim3.util.StringUtil;

	import com.google.appengine.api.channel.ChannelMessage;
	import com.google.appengine.api.channel.ChannelService;
	import com.google.appengine.api.channel.ChannelServiceFactory;
	import com.google.appengine.api.users.User;
	import com.google.appengine.api.users.UserService;
	import com.google.appengine.api.users.UserServiceFactory;

	public class ChannelController extends Controller {

	@Override
	protected Navigation run() throws Exception {
	response.setCharacterEncoding("UTF-8");
	response.setContentType("application/json");

	UserService userService = UserServiceFactory.getUserService();
	User user = userService.getCurrentUser();
	if (user == null) {
	String loginURL = userService.createLoginURL("/");
	JSONObject jsonObject = new JSONObject();
	jsonObject.put("redirectTo", loginURL);
	Writer writer = new PrintWriter(response.getOutputStream());
	writer.write(jsonObject.toString());
	writer.flush();

	return null;
	}

	{
	ChannelUser channelUser = new ChannelUser();
	channelUser.setKey(Datastore.createKey(ChannelUser.class,
	user.getUserId()));
	channelUser.setUser(user);
	Datastore.put(channelUser);
	}

	if (isGet()) {
	String token = getToken(user.getUserId());
	JSONObject jsonObject = new JSONObject();
	jsonObject.put("userId", user.getUserId());
	jsonObject.put("token", token);
	Writer writer = new PrintWriter(response.getOutputStream());
	writer.write(jsonObject.toString());
	writer.flush();

	} else {
	String message = asString("message");
	if (StringUtil.isEmpty(message)) {
	return null;
	}
	List<ChannelUser> list = Datastore.query(ChannelUser.class)
	.asList();
	for (ChannelUser channelUser : list) {
	sendUpdateToUser(channelUser.getKey().getName(), message);
	}
	response.getOutputStream().write("{}".getBytes());
	}

	return null;
	}

	void sendUpdateToUser(String userId, String message) {
	ChannelService channelService = ChannelServiceFactory
	.getChannelService();
	channelService.sendMessage(new ChannelMessage(userId, message));
	}

	String getToken(String userId) {
	ChannelService channelService = ChannelServiceFactory
	.getChannelService();
	String token = channelService.createChannel(userId);
	return token;
	}
	}
	import org.slim3.datastore.Attribute;
	import org.slim3.datastore.Model;

	import com.google.appengine.api.datastore.Key;
	import com.google.appengine.api.users.User;

	@Model
	public class ChannelUser {

	@Attribute(primaryKey = true)
	Key key;

	User user;

	/**
	* @return the key
	*/
	public Key getKey() {
	return key;
	}

	/**
	* @param key
	* the key to set
	*/
	public void setKey(Key key) {
	this.key = key;
	}

	/**
	* @return the user
	*/
	public User getUser() {
	return user;
	}

	/**
	* @param user
	* the user to set
	*/
	public void setUser(User user) {
	this.user = user;
	}
	}
	<html>
	<head>
	<meta http-equiv="content-type" content="text/html; charset=utf-8">
	<script src="/_ah/channel/jsapi"></script>
	<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
	<title>Channel API</title>

	<script type="text/javascript">
	var socket;
	$(document).ready(function () {
	$.ajax({
	type:"GET",
	url:"/channel",
	contentType:"application/json",
	dataType:"json",
	data:{},
	success:function (data) {
	console.log(data);
	if (data.redirectTo) {
	window.location = data.redirectTo;
	return;
	}

	var channel = new goog.appengine.Channel(data.token);
	socket = channel.open();

	socket.onopen = function () {
	addText("接続が開始されました。データを送信できます");
	};
	socket.onerror = function () {
	addText("サーバでエラー！");
	};
	socket.onclose = function () {
	addText("接続が正常に終了しました");
	};
	socket.onmessage = function (data) {
	console.log(data);
	addText(data.data);
	};

	addText("あなたのuserIdは" + data.userId + "です。");
	}
	});

	$("#send").on("click", function () {
	$.ajax({
	type:"POST",
	url:"/channel",
	data:{
	message:$("#message").val()
	},
	success:function (data) {
	console.log(data);
	}
	});

	});
	});

	function addText(text) {
	console.log(text);
	$("<div>").text(text).appendTo($("#content"));
	}
	</script>
	</head>
	<body>

	<div id="content">
	</div>

	<input id="message" type="text" value="">
	<input id="send" type="button" value="データを送信">

	</body>
	</html>