package org.jboss.aerogear.unifiedpush.message.sender;
/**
* JBoss, Home of Professional Open Source
* Copyright Red Hat, Inc., and individual contributors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import org.jboss.aerogear.unifiedpush.api.ChromePackagedAppVariant;
import org.jboss.aerogear.unifiedpush.api.Variant;
import org.jboss.aerogear.unifiedpush.message.helper.ChromePackagedAppTokenCache;
import org.jboss.aerogear.unifiedpush.message.UnifiedPushMessage;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
public class GCMForChromePushNotificationSender implements PushNotificationSender {
private static final Charset UTF_8 = Charset.forName("UTF-8");
private static final String MESSAGE_URL = "https://www.googleapis.com/gcm_for_chrome/v1/messages";
private static final String ACCESS_TOKEN_URL = "https://accounts.google.com/o/oauth2/token";
private final Logger logger = Logger.getLogger(GCMForChromePushNotificationSender.class.getName());
// We need a place to hold the current access token/expire time for each GCM for Chrome application. Not good practice to always get a new access token
private Map<String, ChromePackagedAppTokenCache> accessTokenMap = new HashMap<String, ChromePackagedAppTokenCache>();
public void sendPushMessage(Variant variant, Collection<String> tokens, UnifiedPushMessage pushMessage, NotificationSenderCallback callback) {
// no need to send empty list
if(tokens.isEmpty()) {
return;
}
final ChromePackagedAppVariant chromePackagedAppVariant = (ChromePackagedAppVariant) variant;
String accessToken = fetchAccessToken(chromePackagedAppVariant);
// iterate over all the given channelIDs
for (String channelID : tokens) {
HttpURLConnection conn = null;
try {
final String clientURL = MESSAGE_URL;
// POST the payload to the GCM For Chrome server
conn = post(clientURL, "{'channelId': '" + channelID + "', 'subchannelId': '0', 'payload': '" + pushMessage.getAlert() + "'}", accessToken);
int chromePackagedAppStatusCode = conn.getResponseCode();
// did we get a 'good' status code?
if (chromePackagedAppStatusCode < 400) {
callback.onSuccess();
} else {
logger.log(Level.SEVERE, "Error during Post execution to GCM for Chrome Network, status code was: " + chromePackagedAppStatusCode);
callback.onError();
}
} catch (IOException e) {
logger.log(Level.SEVERE, "Error during Post execution to GCM for Chrome Network", e);
callback.onError();
} finally {
// tear down
if (conn != null ) {
conn.disconnect();
}
}
}
}
/**
* Returns HttpURLConnection that 'posts' the given body to the given URL.
*/
protected HttpURLConnection post(String url, String body, String accessToken) throws IOException {
if (url == null || body == null) {
throw new IllegalArgumentException("arguments cannot be null");
}
byte[] bytes = body.getBytes(UTF_8);
HttpURLConnection conn = getConnection(url);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setFixedLengthStreamingMode(bytes.length);
conn.setRequestProperty("Content-Type", "application/json");
conn.setRequestProperty("Authorization", "Bearer " + accessToken );
conn.setRequestMethod("POST");
OutputStream out = null;
try {
out = conn.getOutputStream();
out.write(bytes);
} finally {
// in case something blows up, while writing
// the payload, we wanna close the stream:
if (out != null) {
out.close();
}
}
return conn;
}
protected HttpURLConnection refreshAccessToken( ChromePackagedAppVariant chromePackagedAppVariant ) throws IOException{
String body = "client_secret="+chromePackagedAppVariant.getClientSecret()+"&grant_type=refresh_token&refresh_token="+chromePackagedAppVariant.getRefreshToken()+"&client_id="+chromePackagedAppVariant.getClientId();
byte[] bytes = body.getBytes(UTF_8);
HttpURLConnection conn = getConnection(ACCESS_TOKEN_URL);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setFixedLengthStreamingMode(bytes.length);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
OutputStream out = null;
try {
out = conn.getOutputStream();
out.write(bytes);
} finally {
// in case something blows up, while writing
// the payload, we wanna close the stream:
if (out != null) {
out.close();
}
}
return conn;
}
/**
*
* @param chromePackagedAppVariant
* @return a valid access token
*/
protected String fetchAccessToken(ChromePackagedAppVariant chromePackagedAppVariant) {
HttpURLConnection accessTokenConn = null;
JSONParser jsonParser = new JSONParser();
ChromePackagedAppTokenCache accessTokenObject = null;
String accessToken = null;
long expireTime = 0; // in milliseconds
try {
// Not good practice to always get a new access token. so only get one if it is expired or null
accessTokenObject = accessTokenMap.get(chromePackagedAppVariant.getClientId());
if( accessTokenObject != null ) {
accessToken = accessTokenObject.getAccessToken();
expireTime = accessTokenObject.getExpiresIn();
}
if( accessToken == null || expireTime < new Date().getTime() ) {
accessTokenConn = refreshAccessToken(chromePackagedAppVariant);
String stringResponse = getString(accessTokenConn.getInputStream());
accessToken = ((JSONObject)jsonParser.parse(stringResponse)).get("access_token").toString();
String expiresIn = ((JSONObject)jsonParser.parse(stringResponse)).get("expires_in").toString();
// Convert to millis
long ex = Long.parseLong( expiresIn );
expireTime = new Date().getTime() + (ex * 1000);
if( accessTokenObject == null ) {
accessTokenObject = new ChromePackagedAppTokenCache();
}
accessTokenObject.setAccessToken(accessToken);
accessTokenObject.setExpiresIn(expireTime);
accessTokenMap.put(chromePackagedAppVariant.getClientId(),accessTokenObject);
}
} catch (IOException e) {
logger.log(Level.SEVERE, "Error during Post execution to GCM for Chrome Network For access token refresh", e);
} catch (ParseException e) {
logger.log(Level.SEVERE, "Error during Parse of Response ", e);
} finally {
// tear down
if (accessTokenConn != null ) {
accessTokenConn.disconnect();
}
}
return accessToken;
}
/**
* Convenience method to open/establish a HttpURLConnection.
*/
protected HttpURLConnection getConnection(String url) throws IOException {
HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
return conn;
}
/**
* Convenience method to convert an InputStream to a String.
*
* <p>
* If the stream ends in a newline character, it will be stripped.
*/
protected static String getString(InputStream stream) throws IOException {
BufferedReader reader =
new BufferedReader(new InputStreamReader(nonNull(stream)));
StringBuilder content = new StringBuilder();
String newLine;
do {
newLine = reader.readLine();
if (newLine != null) {
content.append(newLine).append('\n');
}
} while (newLine != null);
if (content.length() > 0) {
// strip last newline
content.setLength(content.length() - 1);
}
return content.toString();
}
static <T> T nonNull(T argument) {
if (argument == null) {
throw new IllegalArgumentException("argument cannot be null");
}
return argument;
}
}