Android Tutorial Simple Push Framework

It is recommended to use Firebase for new projects: FirebaseNotifications - Push messages / Firebase Cloud Messaging (FCM)

This solution allows you to use the standard GCM push framework without an online server.

You should first be familiar with GCM and get an API Key and Project id as explained here:
Android push notification (GCM) framework and tutorial

The desktop solution is based on this B4J project: Building a mini "Email based server"

When a user registers the device, an email is sent to the desktop tool. The desktop tool then adds the device to an internal store. If the desktop tool is not online then nothing bad happens. The mail will wait until it the tool is started.

The emails are only used for the registration process.

Note that you can send to multiple targets at once with this solution (unlike the other solution).
As it is written in B4J it should be simple to extend it as needed.

In order to use it you should set the ApiKey variable in the B4J project as well as the mailbox parameters.

You also need to set the mailbox parameters on the device (PushService) and set the SenderId in the Main module.

Tips / Notes

- The B4J project depends on jMsgboxes library (and other internal libraries). It also requires B4J v1.05+.
- If you plan to distribute your app on many devices then you should probably not use a free mail service such as Gmail for the devices. You can use the default email client instead. However in that case it is better to "obfuscate" the message before sending it as the user will see the mail content.

 

[schimanski]

Ok, I have found this:

http://developer.android.com/training/cloudsync/gcm.html

If I understand it right, it is possible to hold up to 1000 IDs in one push and send up to 1000 messages to my app user. Is that right?

 

[Erel]

About the package name, the package name identifies your app. If you change it then Google will treat your app as a new app without any relation to the previous one.

The data is limited to 4k. You can add up to 1000 registration ids in a single request.

 

[schimanski]

That was, what i wanted to hear....much thanks..

 

[rwblinn]

Hi All,

cant get the client to work. Have setup a project in GCM with project name, project id and number. also obtained a server api key.
After modifying the parameter, the desktop receives emails, but for the client when entering a name and press register nothing happens.

I read in this thread, the mention of registering the app at google. How to do that?

Appreciate any advice.

 

[Erel]

You only need to receive an API key and project ID from Google.

If the desktop app received an email from the device then the device was registered successfully.

 

[rwblinn]

You only need to receive an API key and project ID from Google.

If the desktop app received an email from the device then the device was registered successfully.

Hi Erel,

the desktop did not receive an email from the device (but emails from my googlemail.com account).
The B4A client, used via the emulator, does not sent an email! The log states "Push service started", but then nothing happens.

Do I need to use the app on the device and can not use the emulator?

 

[Erel]

Try it on a real device. As a general rule I recommend you to avoid using the emulator at all.

 

[rwblinn]

Hi Erel,

got it to work:

• In pushexample.b4a the senderID is the Google Project Number (12 Digit) and not the Project ID
• Real Device using Android 2.3.5 did not work - Error Message: Invalid Service
  
• Real Device using Android 4.3 registration successful
• Changed the package name to another then the default
• In B4J POP3 an error occurs when retrieving the devices - using JavaFX 8 :
  java.lang.NoSuchMethodError: javafx.scene.control.CheckBoxTreeItem.setIndependent(Ljava/lang/Boolean;)V
  This happens when initializing the CheckTreeViewItem in Sub ShowDevices.
• To test used a registered name direct and message came through

Thanks for your support --- will build further upon this.

 

[Erel]

Can you post the full error message for the NoSuchMethodError?

 

[rwblinn]

Hi Erel,

as requested

main._showdevices (java line: 376)
java.lang.NoSuchMethodError: javafx.scene.control.CheckBoxTreeItem.setIndependent(Ljava/lang/Boolean;)V
    at anywheresoftware.b4j.objects.TreeViewWrapper$CheckBoxTreeItemWrapper.Initialize(TreeViewWrapper.java:158)
    at b4j.example.main._showdevices(main.java:376)
    at b4j.example.main._appstart(main.java:93)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:84)
    at b4j.example.main.start(main.java:35)
    at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837)
    at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
    at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
    at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
    at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
    at java.lang.Thread.run(Thread.java:745)

 

[Erel]

I see it too. Seems like they changed the method signature from Boolean to boolean breaking binary compatibility.

This issue is fixed in jFX v2.01: http://www.b4x.com/android/forum/threads/jfx-v2-01-java-8-and-checkboxtreeitem.42482/

 

[rwblinn]

Hi Erel,

using jFX 2.01 following error when requesting checkboxtreeitem check (... ti.Checked...)- in POP3 example.

main._btnsend_action (java line: 123)
java.lang.NoSuchMethodError: javafx.scene.control.CheckBoxTreeItem.isSelected()Ljava/lang/Boolean;
    at anywheresoftware.b4j.objects.TreeViewWrapper$CheckBoxTreeItemWrapper.getChecked(TreeViewWrapper.java:185)
    at b4j.example.main._btnsend_action(main.java:123)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
    at anywheresoftware.b4a.BA$2.run(BA.java:165)
    at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
    at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
    at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
    at java.lang.Thread.run(Thread.java:745)

 

[Erel]

I've uploaded a new jar (same version). It will fix this issue.

 

[rwblinn]

Hi Erel,

found one more = when setting

treeitem.checked = true

following error occurs:

java.lang.NoSuchMethodError: javafx.scene.control.CheckBoxTreeItem.setSelected(Ljava/lang/Boolean;)V

 

[Erel]

Fixed.

 

[Levisvv]

Erel can you explain how communications with this simple method works offline?
Is the B4J application simply connecting directly to the Android devices over TCP/IP? without needing to connect to the online GCM server? Other than the email needed to register devices, can this work on a closed/secured network that has absolutely no internet access?

 

[Erel]

Is the B4J application simply connecting directly to the Android devices over TCP/IP?

No.

The B4J app does two things:
1. Monitors the mailbox looking for new devices.
2. Connects to Google GCM servers to send messages.

 

[Giacomo Cuciniello]

I have a strange behaviour.
The work on google api is done.
my phone send the mail to the desktop app.
desktop app receive the mail and include my phome in the device list.
when I send a message from the desktop app it seems ok
{"multicast_id":7010969338997093013,"success":1,"failure":0,"canonical_ids":0,"results":[{"message_id":"0:1408805079180448%22199a2af9fd7ecd"}]}
but nothing arrive on the phone.
the app is running on the phone, internet connection is ON but I don't receive any message.
What can I check?
the only difference that I find is that my project ID is of 13 digit and not 12 but registation is achived.
thanks for your help

 

[Erel]

Are you able to see the device logs?

 

[Giacomo Cuciniello]

thank you Erel,
I don't understand why but today it is working

LogCat connected to: B4A-Bridge: samsung GT-I9300
--------- beginning of /dev/log/main
** Activity (main) Create, isFirst = true **
** Activity (main) Resume **
** Service (service1) Create **
** Service (service1) Start **
Connected to B4A-Bridge (Wifi)
Installing file.
** Activity (main) Pause, UserClosed = false **
PackageAdded: package:anywheresoftware.b4a.samples.push
** Activity (main) Create, isFirst = true **
** Activity (main) Resume **
** Activity (main) Pause, UserClosed = false **
** Activity (main) Resume **
** Activity (main) Pause, UserClosed = false **
** Activity (main) Resume **
** Service (pushservice) Create **
** Service (pushservice) Start **
** Service (pushservice) Start **
** Service (pushservice) Start **
Bundle[{data=ppo, collapse_key=do_not_collapse, from=1048272702146}]
New message arrived: ppo

I noted the messages arrive even after phone rebott without starting again the app.
thanks again