使用content_available向iOS发送GCM推送通知（无法从非活动状态调用）

Question

我正在开发基于Java REST的Web服务，尝试通过Google Cloud Messaging将消息从Java API发送到iOS设备。出于学习目的，我使用了Google iOS示例代码，并且当应用程序在前台时，我能够成功发送消息，但是当应用程序在后台时无法正常工作。我尝试了多种“content_available”标志的变化，这个标志负责在后台调用应用程序。当应用程序在前台时，它能够很好地工作。我正在尝试在应用程序在后台时显示通知。

HttpClient client = new DefaultHttpClient();
HttpPost post = null;
try {
    post = new HttpPost("https://android.googleapis.com/gcm/send");
} catch (URISyntaxException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
String regisID="My_iOS_Registration_Id-GVnH1gEsJ";
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
List<NameValuePair> notificationData = new ArrayList<NameValuePair>(1);
notificationData.add(new BasicNameValuePair("title", "title"));
JSONObject obj=new JSONObject();
obj.put("title", "title");
obj.put("alert", "title");
obj.put("sound", "default");
obj.put("badge", "1");
nameValuePairs.add(new BasicNameValuePair("to", regisID));
nameValuePairs.add(new BasicNameValuePair("notification", obj.toString()));
nameValuePairs.add(new BasicNameValuePair("content_available", "true"));

post.setHeader("Authorization",
        "key=MyKey");
try {
    HttpEntity entity = new UrlEncodedFormEntity(nameValuePairs);
} catch (UnsupportedEncodingException e1) {
    // TODO Auto-generated catch block
    e1.printStackTrace();
}
try {
    post.setEntity(new UrlEncodedFormEntity(nameValuePairs));
} catch (UnsupportedEncodingException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
HttpResponse response = null;
try {
    response = client.execute(post);
} catch (HttpException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
HttpEntity entity1 = response.getEntity();
try {
    System.out.println("Hi response is : " + EntityUtils.toString(entity1));
} catch (ParseException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
return response.getStatusLine().toString();

这是我用于接收通知的iOS应用程序委托代码，基本上是谷歌示例代码，添加了显示通知的代码

// [START ack_message_reception]
- (void)application:(UIApplication *)application
    didReceiveRemoteNotification:(NSDictionary *)userInfo {
  NSLog(@" foregraound one Notification received: %@", userInfo);
  // This works only if the app started the GCM service
  [[GCMService sharedInstance] appDidReceiveMessage:userInfo];
  // Handle the received message
  // [START_EXCLUDE]
  [[NSNotificationCenter defaultCenter] postNotificationName:_messageKey
                                                  object:nil
                                                userInfo:userInfo];
  // [END_EXCLUDE]


  UILocalNotification *notification = [[UILocalNotification alloc]init];
  notification.repeatInterval = NSDayCalendarUnit;
  [notification setAlertBody:@"Hello world"];
  [notification setFireDate:[NSDate dateWithTimeIntervalSinceNow:1]];
  [notification setTimeZone:[NSTimeZone  defaultTimeZone]];
  [application setScheduledLocalNotifications:[NSArray      arrayWithObject:notification]];
}

- (void)application:(UIApplication *)application
    didReceiveRemoteNotification:(NSDictionary *)userInfo
    fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))handler {
  NSLog(@" backgroun one Notification received: %@", userInfo);
  // This works only if the app started the GCM service
  [[GCMService sharedInstance] appDidReceiveMessage:userInfo];
  // Handle the received message
  // Invoke the completion handler passing the appropriate         UIBackgroundFetchResult value
  // [START_EXCLUDE]
  [[NSNotificationCenter defaultCenter] postNotificationName:_messageKey
                                                  object:nil
                                                userInfo:userInfo];
  handler(UIBackgroundFetchResultNoData);
  // [END_EXCLUDE]

  UILocalNotification *notification = [[UILocalNotification alloc]init];
  notification.repeatInterval = NSDayCalendarUnit;
  [notification setAlertBody:@"Hello world"];
  [notification setFireDate:[NSDate dateWithTimeIntervalSinceNow:1]];
  [notification setTimeZone:[NSTimeZone  defaultTimeZone]];
  [application setScheduledLocalNotifications:[NSArray    arrayWithObject:notification]];
}

我尝试将数据作为JSON字符串发送到通知中，使用各种变化的"content_available"、"content-available"和值的变化为'1'、true、TRUE。似乎没有反映我的更改。我尝试将'sound'发送为'default'，因为我在一些问题中发现它应该会受到影响。我已经在Android上实现了这个功能，而且它的效果非常好。基本上，根据我通过GCM文档和APNS文档获得的知识，它应该调用一个由"content-available"决定的第二个方法，但对我来说却不起作用。

这是一个带有content_available的Google文档链接。

https://developers.google.com/cloud-messaging/server-ref#downstream

https://developers.google.com/cloud-messaging/server#payload

要查看“content_available”的部分，请搜索页面以获取有关该内容的信息。

- chinmay gajjar

Answer 1

我通过仔细参考文档解决了这个问题，我的新的 Java 工作代码如下。

JSONObject subobj = new JSONObject();
subobj.put("sound", "default");
subobj.put("badge", "12");
subobj.put("title", "default");

JSONObject obj = new JSONObject();
obj.put("to", regisID);
obj.put("notification", subobj);
obj.put("content_available", new Boolean(true));

post.setHeader("Authorization",
        "key=MyKey");

post.setHeader("Content-Type",
        "application/json");
try {
    HttpEntity entity = new UrlEncodedFormEntity(nameValuePairs);
} catch (UnsupportedEncodingException e1) {
    // TODO Auto-generated catch block
    e1.printStackTrace();
}

- chinmay gajjar