Develop Reference

java.lang.NoClassDefFoundError: com.google.android.gms.gcm.GoogleCloudMessaging

I am developing the GCM sample app using http://javapapers.com/android/google-cloud-messaging-gcm-for-android-and-push-notifications/#comment-103785.
I am unable to register gcm server.I am getting the following error.I have goggled it .but i couldn't find the solution and all the solutions were about jar files i have done all the changes but i couldn't get it.
Error
FATAL EXCEPTION: main
java.lang.NoClassDefFoundError: com.google.android.gms.gcm.GoogleCloudMessaging
com.sanjeev.integrationapp.RegisterActivity.registerGCM(RegisterActivity.java:80)
com.sanjeev.integrationapp.RegisterActivity$1.onClick(RegisterActivity.java:47)
at android.view.View.performClick(View.java:4084)
at android.view.View$PerformClick.run(View.java:16966)
at android.os.Handler.handleCallback(Handler.java:615)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4745)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
And my class code follows
public class RegisterActivity extends Activity {
Button btnGCMRegister;
Button btnAppShare;
GoogleCloudMessaging gcm;
Context context;
String regId;
public static final String REG_ID = "regId";
private static final String APP_VERSION = "appVersion";
static final String TAG = "Register Activity";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
context = getApplicationContext();
btnGCMRegister = (Button) findViewById(R.id.btnGCMRegister);
btnGCMRegister.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
if (TextUtils.isEmpty(regId)) {
regId = registerGCM();
Log.d("RegisterActivity", "GCM RegId: " + regId);
} else {
Toast.makeText(getApplicationContext(),
"Already Registered with GCM Server!",
Toast.LENGTH_LONG).show();
}
}
});
btnAppShare = (Button) findViewById(R.id.btnAppShare);
btnAppShare.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
if (TextUtils.isEmpty(regId)) {
Toast.makeText(getApplicationContext(), "RegId is empty!",
Toast.LENGTH_LONG).show();
} else {
Intent i = new Intent(getApplicationContext(),
MainActivity.class);
i.putExtra("regId", regId);
Log.d("RegisterActivity",
"onClick of Share: Before starting main activity.");
startActivity(i);
finish();
Log.d("RegisterActivity", "onClick of Share: After finish.");
}
}
});
}
public String registerGCM() {
// below line I am getting error
gcm = GoogleCloudMessaging.getInstance(this);
regId = getRegistrationId(context);
if (TextUtils.isEmpty(regId)) {
registerInBackground();
Log.d("RegisterActivity",
"registerGCM - successfully registered with GCM server - regId: "
+ regId);
} else {
Toast.makeText(getApplicationContext(),
"RegId already available. RegId: " + regId,
Toast.LENGTH_LONG).show();
}
return regId;
}
#SuppressLint("NewApi")
private String getRegistrationId(Context context) {
final SharedPreferences prefs = getSharedPreferences(
MainActivity.class.getSimpleName(), Context.MODE_PRIVATE);
String registrationId = prefs.getString(REG_ID, "");
if (registrationId.isEmpty()) {
Log.i(TAG, "Registration not found.");
return "";
}
int registeredVersion = prefs.getInt(APP_VERSION, Integer.MIN_VALUE);
int currentVersion = getAppVersion(context);
if (registeredVersion != currentVersion) {
Log.i(TAG, "App version changed.");
return "";
}
return registrationId;
}
private static int getAppVersion(Context context) {
try {
PackageInfo packageInfo = context.getPackageManager()
.getPackageInfo(context.getPackageName(), 0);
return packageInfo.versionCode;
} catch (NameNotFoundException e) {
Log.d("RegisterActivity","I never expected this! Going down, going down!" + e);
throw new RuntimeException(e);
}
}
private void registerInBackground() {
new AsyncTask<Void, Void, String>() {
#Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
regId = gcm.register(Config.GOOGLE_PROJECT_ID);
Log.d("RegisterActivity", "registerInBackground - regId: "
+ regId);
msg = "Device registered, registration ID=" + regId;
storeRegistrationId(context, regId);
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
Log.d("RegisterActivity", "Error: " + msg);
}
Log.d("RegisterActivity", "AsyncTask completed: " + msg);
return msg;
}
#Override
protected void onPostExecute(String msg) {
Toast.makeText(getApplicationContext(),
"Registered with GCM Server." + msg,
Toast.LENGTH_LONG)
.show();
}
}.execute(null, null, null);
}
private void storeRegistrationId(Context context, String regId) {
final SharedPreferences prefs = getSharedPreferences(
MainActivity.class.getSimpleName(), Context.MODE_PRIVATE);
int appVersion = getAppVersion(context);
Log.i(TAG, "Saving regId on app version " + appVersion);
SharedPreferences.Editor editor = prefs.edit();
editor.putString(REG_ID, regId);
editor.putInt(APP_VERSION, appVersion);
editor.commit();
}
}

Here, no need to import google_play_services_lib in your workspace, google_play_services_lib has a jar named google-play-services.jar which needs to be included in your GCM App.
google-play-services.jar contains all GCM related classes, thats why google_play_services_lib has been added as dependency on GCM Android Project. The simplest thing you can do is to add that jar on your GCM project instead of adding dependency of google_play_services_lib project.
To add jar in android project you have to do following things,
1. First create a libs folder under you project, its a libs folder and not lib.
2. Then copy google-play-services.jar inside libs folder.
3. Then right click on the google-play-services.jar and select Build Path > Add to Build Path.
You can see Android Private Libraries created under your project's root folder which will contain this jar.
Note: Path of jar file - sdk\extras\google\google_play_services\libproject\google-play-services_lib\libs

how to resolve Android gcm notifications duplicate messages

Hi am getting duplicate notification from gcm server , how to resolve it
public class RegisterActivity{
private GoogleCloudMessaging gcm;
Context context;
String regId;
private static final String REG_ID = "regId";
private static final String APP_VERSION = "appVersion";
static final String TAG = "Register Activity";
private final static int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;
private GCMRegistrationCallBack registeredActivity;
private Error error;
public void registerGCM(Context _context)
{
context = _context;
if(!checkPlayServices()){
Log.e(TAG, "This device is not supported.");
return;
}
registeredActivity = (GCMRegistrationCallBack) _context;
gcm = GoogleCloudMessaging.getInstance(context);
regId = getRegistrationId(context);
if(TextUtils.isEmpty(regId))
{
registerInBackground();
Log.d("RegisterActivity",
"registerGCM - successfully registered with GCM server - regId: "
+ regId);
}
else
{
registeredActivity.didFinishRegisteringWithGCM(regId);
}
}
private String getRegistrationId(Context context)
{
final SharedPreferences prefs = context.getSharedPreferences(
GCMRegistrationCallBack.class.getSimpleName(), Context.MODE_PRIVATE);
String registrationId = prefs.getString(REG_ID, "");
if (registrationId.isEmpty()) {
Log.i(TAG, "Registration not found.");
return "";
}
int registeredVersion = prefs.getInt(APP_VERSION, Integer.MIN_VALUE);
int currentVersion = getAppVersion(context);
if (registeredVersion != currentVersion) {
Log.i(TAG, "App version changed.");
return "";
}
return registrationId;
}
private static int getAppVersion(Context context) {
try {
PackageInfo packageInfo = context.getPackageManager()
.getPackageInfo(context.getPackageName(), 0);
return packageInfo.versionCode;
} catch (NameNotFoundException e) {
Log.d("RegisterActivity",
"I never expected this! Going down, going down!" + e);
throw new RuntimeException(e);
}
}
private void registerInBackground() {
new AsyncTask<Void, Void, String>() {
#Override
protected String doInBackground(Void... params) {
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
regId = gcm.register(Config.GOOGLE_PROJECT_ID);
storeRegistrationId(context, regId);
}
catch(UnknownHostException _exception)
{
error = new Error("UnknownHostException");
callErrorCallBackOnMainThread();
}
catch(SocketTimeoutException _exception)
{
error = new Error("SocketTimeoutException");
callErrorCallBackOnMainThread();
}
catch (IOException _exception) {
error = new Error(_exception.getMessage());
callErrorCallBackOnMainThread();
}
catch(Exception _exception)
{
error = new Error("unknown exception");
callErrorCallBackOnMainThread();
}
return regId;
}
#Override
protected void onPostExecute(String msg) {
if(!TextUtils.isEmpty(msg))
registeredActivity.didFinishRegisteringWithGCM(regId);
}
}.execute(null, null, null);
}
private void callErrorCallBackOnMainThread()
{
Activity regAvtivity = (Activity)registeredActivity;
regAvtivity.runOnUiThread(new Runnable()
{
public void run()
{
registeredActivity.didFailedToReceiveRegistrationId(error);
}
});
}
private void storeRegistrationId(Context context, String regId) {
final SharedPreferences prefs = context.getSharedPreferences(
GCMRegistrationCallBack.class.getSimpleName(), Context.MODE_PRIVATE);
int appVersion = getAppVersion(context);
Log.i(TAG, "Saving regId on app version " + appVersion);
SharedPreferences.Editor editor = prefs.edit();
editor.putString(REG_ID, regId);
editor.putInt(APP_VERSION, appVersion);
editor.commit();
}
/**
* Check the device to make sure it has the Google Play Services APK. If
* it doesn't, display a dialog that allows users to download the APK from
* the Google Play Store or enable it in the device's system settings.
*/
private boolean checkPlayServices() {
int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(context);
if (resultCode != ConnectionResult.SUCCESS) {
if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) {
GooglePlayServicesUtil.getErrorDialog(resultCode, (Activity)context,
PLAY_SERVICES_RESOLUTION_REQUEST).show();
} else {
Log.i(TAG, "This device is not supported.");
}
return false;
}
return true;
}
}
Above code for getting registration number please correct me anything wrong... but some time am getting duplicate notification.
thanks

You should use Canonical IDs for this. This might happen because you registered with several IDs for the same device. Using canonical IDs will set your ID to be the last registration you've made.
As per the GCM reference about this:
Canonical IDs
On the server side, as long as the application is behaving well, everything should work normally. However, if a bug in the application triggers multiple registrations for the same device, it can be hard to reconcile state and you might end up with duplicate messages.
GCM provides a facility called "canonical registration IDs" to easily recover from these situations. A canonical registration ID is defined to be the ID of the last registration requested by your application. This is the ID that the server should use when sending messages to the device.
If later on you try to send a message using a different registration ID, GCM will process the request as usual, but it will include the canonical registration ID in the registration_id field of the response. Make sure to replace the registration ID stored in your server with this canonical ID, as eventually the ID you're using will stop working.
More info here.

java.lang.NullPointerException when execute Asynctask

I want to register the user to gcm server so I use this function :
private void registerInBackground() {
new AsyncTask<Void,Void,String>() {
#Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
regid = gcm.register(SENDER_ID);
msg = "Device registered, registration ID=" + regid;
// You should send the registration ID to your server over HTTP,
// so it can use GCM/HTTP or CCS to send messages to your app.
// The request to your server should be authenticated if your app
// is using accounts.
sendRegistrationIdToBackend();
// For this demo: we don't need to send it because the device
// will send upstream messages to a server that echo back the
// message using the 'from' address in the message.
// Persist the regID - no need to register again.
// storeRegistrationId(context, regid);
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
// If there is an error, don't just keep trying to register.
// Require the user to click a button again, or perform
// exponential back-off.
}
return msg;
}
#Override
protected void onPostExecute(String msg) {
mDisplay.append(msg + "\n");
}
}.execute(null, null, null);
}
it is the same function as described here, so I am surprised to get an NullPOinterEXCEPTION erro, I think it is because this line: execute(null,null,null,null), but this what google give me! what should I do ?

Gcm unregistration

I am working on GCM in android.
I am done with the registration of the device with GCM by using following code which registers the device asynchronously.
private void registerInBackground() {
new AsyncTask<Void, Void, String>() {
#Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
regid = gcm.register(SENDER_ID);
msg = "Device registered, registration ID=" + regid;
storeRegistrationId(context, regid);
msg="Registration success. Regid: "+regid;
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
// If there is an error, don't just keep trying to register.
// Require the user to click a button again, or perform
// exponential back-off.
}
return msg;
}
#Override
protected void onPostExecute(String msg) {
Log.e("GCM", msg);
}
}.execute(null, null, null);
}
registration is done in registrationActivity
Now i want to unregister the device.
Unregister command is sent by the server app, which is received on android side.
How can i unregister the device from the activity (mdmActivity) where i process the received messages.
Whether it should be asyn or sync??
Is it wrong to create an object for registrationActivity and calling a unregisterInBackground function using that object as below from mdmActivity?
RegistrationActivity reg=new RegistrationActivity();
reg.unregisterInBackground();
And the unregisterInBackground function in registrationActivity is as follows:
protected void unregisterInBackground() {
new AsyncTask<Void, Void, String>() {
#Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
gcm.unregister();
msg = "Device unregistered, registration ID=" + regid;
// delete the regID
deleteRegistrationId(context, regid);
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
}
return msg;
}
#Override
protected void onPostExecute(String msg) {
Log.e("unregistration", msg);
}
}.execute(null, null, null);
}
Need your help!! Thanks in advance.

unregister() is also blocking, like register(). As such, you really need to run it in a background thread similar to the way you did with an AsyncTask.
You call it on the GCM instance, so I think it's fine to call it from whichever activity as long as you have that gcm instance.
You might want to read this before implementing the unregister functionality.

registration id is null from gcm in android 2.3.3, 2.3.5 but it is not null and working in android 2.3.4, 4.0.4

private void registerClient() {
try {
GCMRegistrar.checkDevice(this);
GCMRegistrar.checkManifest(this);
regId = GCMRegistrar.getRegistrationId(this);
if (regId.equals("")) {
registrationStatus = "Registering...";
GCMRegistrar.register(this, "1074338555805");
regId = GCMRegistrar.getRegistrationId(this);
registrationStatus = "Registration Acquired";
sendRegistrationToServer();
} else {
registrationStatus = "Already registered";
}
} catch (Exception e) {
e.printStackTrace();
registrationStatus = e.getMessage();
}
}
registration id is null from gcm in android 2.3.3, 2.3.5 but it is not null and working in android 2.3.4, 4.0.4.

As quite clearly stated on the Google Play Services set-up guide.
https://developer.android.com/google/gcm/client.html
Application OnCreate:
// Check device for Play Services APK. If check succeeds, proceed with
// GCM registration.
if (checkPlayServices()) {
gcm = GoogleCloudMessaging.getInstance(this);
regid = getRegistrationId(context);
if (regid.isEmpty()) {
registerInBackground();
}
} else {
Log.i(TAG, "No valid Google Play Services APK found.");
}
Register in background code:
/**
* Registers the application with GCM servers asynchronously.
* <p>
* Stores the registration ID and app versionCode in the application's
* shared preferences.
*/
private void registerInBackground() {
new AsyncTask() {
#Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
regid = gcm.register(SENDER_ID);
msg = "Device registered, registration ID=" + regid;
// You should send the registration ID to your server over HTTP,
// so it can use GCM/HTTP or CCS to send messages to your app.
// The request to your server should be authenticated if your app
// is using accounts.
sendRegistrationIdToBackend();
// For this demo: we don't need to send it because the device
// will send upstream messages to a server that echo back the
// message using the 'from' address in the message.
// Persist the regID - no need to register again.
storeRegistrationId(context, regid);
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
// If there is an error, don't just keep trying to register.
// Require the user to click a button again, or perform
// exponential back-off.
}
return msg;
}
#Override
protected void onPostExecute(String msg) {
mDisplay.append(msg + "\n");
}
}.execute(null, null, null);
...
}