How to uniquely identify your Android device in code

 My last android project involved tracking each device where my app is installed and storing the information to a database, so that customized content can be shown to that particular user.

Now, had it been a PC, it would have been easy to track the MAC-address of the NIC or an HDD serial to track that device. But what is the equivalent for android?

My research first led me to the IMEI number (TelephonyManager.getDeviceId()). The IMEI is quite popular among the masses and is widely used for tracking the cellphones. The android API provides this ready-made function if you want to go this route:

public static String getDeviceIdTm(Context context)
 {
 TelephonyManager tm=(TelephonyManager)context.getSystemService(Context.TELEPHONY_SERVICE);
 return tm.getDeviceId();
 }

But wait, not all devices are equipped with Telephony. What about tablets and amazon kindle devices? It so happens, that this is just one way to track your device, but it is not full-proof. It will work only for phones and for other devices this function will return null.

This led me to another way of tracking an Android device: An in-built variable that the Android system itself provides you: ANDROID_ID. In theory, this variable is all you need to know to identify your device uniquely:

public static String getDeviceIdAndroid(Context context)
 {
 return Secure.getString(context.getContentResolver(),Secure.ANDROID_ID);
 }

But Alas! Even this is not full-proof. It will work on most modern versions of android (HoneyComb and above). Again, due to a manufacturer bug, it will not return a unique value, but a constant value “9774d56d682e549c” on some handsets.

This led me to a third way of identifying my device which was a bit hackish. I would never intend to use this method if any of the above two methods worked.

public static String getDeviceIdPseudo(Context context)
 {
 String tstr="";
 if (Build.VERSION.SDK_INT > Build.VERSION_CODES.FROYO)
 tstr+= Build.SERIAL;
 tstr += "::" +
 (Build.PRODUCT.length() % 10) + (Build.BOARD.length() % 10) + (Build.BRAND.length() % 10) +
 (Build.CPU_ABI.length() % 10) + (Build.DEVICE.length() % 10) +
 (Build.MANUFACTURER.length() % 10) + (Build.MODEL.length() % 10);
 return tstr;
 }

This method computes a Pseudo-id for your device taking reference to some hardware values. If the previous two methods don’t work, then this is all you are left with for device identification.

I then integrated the above three methods to create a generic method called getDeviceIdUnique() that will work on all android devices – irrespective of whether its a phone/tablet or what make it is:

public static String getDeviceIdUnique(Context context)
 {
 try{
 String a = getDeviceIdTm(context);
 String b = getDeviceIdAndroid(context);
 String c = getDeviceIdPseudo(context);

 if (a!=null && a.length()>0 && a.replace("0", "").length()>0) 
 return a;
 else if (b!=null && b.length()>0 && b.equals("9774d56d682e549c")==false) 
 return b;
 else if (c!=null && c.length()>0) 
 return c;
 else
 return "";
 }
 catch(Exception ex)
 {
 return "";
 }
 }