How can I detect when an Android application is ru

Question

I would like to have my code run slightly differently when running on the emulator than when running on a device. (For example, using 10.0.2.2 instead of a public URL to run against a development server automatically.) What is the best way to detect when an Android application is running in the emulator?

Answer 1

I just look for _sdk, _sdk_ or sdk_, or even just sdk part in Build.PRODUCT:

if(Build.PRODUCT.matches(".*_?sdk_?.*")){
  //-- emulator --
}else{
  //-- other device --
}

Answer 2

Put a file in the file system of the emulator; since the file won't exist on the real device, this should be stable, reliable and easy to fix when it breaks.

Answer 3

you can check the IMEI #, http://developer.android.com/reference/android/telephony/TelephonyManager.html#getDeviceId%28%29

if i recall on the emulator this return 0. however, there's no documentation i can find that guarantees that. although the emulator might not always return 0, it seems pretty safe that a registered phone would not return 0. what would happen on a non-phone android device, or one without a SIM card installed or one that isn't currently registered on the network?

seems like that'd be a bad idea, to depend on that.

it also means you'd need to ask for permission to read the phone state, which is bad if you don't already require it for something else.

if not that, then there's always flipping some bit somewhere before you finally generate your signed app.

Answer 4

Whichever code you use to do emulator detection, I'd highly recommend writing unit tests to cover all the Build.FINGERPRINT, Build.HARDWARE and Build.MANUFACTURER values that you are depending on. Here are some example tests:

@Test
public void testIsEmulatorGenymotion() throws Exception {
    assertThat(
            DeviceUtils.isRunningOnEmulator(
                    "generic/vbox86p/vbox86p:4.1.1/JRO03S/eng.buildbot.20150217.102902:userdebug/test-keys",
                    "vbox86", "Genymotion")).isTrue();

    assertThat(
            DeviceUtils.isRunningOnEmulator(
                    "generic/vbox86p/vbox86p:5.1/LMY47D/buildbot06092001:userdebug/test-keys", "vbox86",
                    "Genymotion")).isTrue();
}

@Test
public void testIsEmulatorDefaultAndroidEmulator() throws Exception {
    assertThat(
            DeviceUtils.isRunningOnEmulator(
                    "generic_x86/sdk_google_phone_x86/generic_x86:5.0.2/LSY66H/1960483:eng/test-keys", "goldfish",
                    "unknown")).isTrue();

    assertThat(
            DeviceUtils.isRunningOnEmulator(
                    "Android/sdk_google_phone_x86_64/generic_x86_64:6.0/MASTER/2469028:userdebug/test-keys",
                    "ranchu", "unknown")).isTrue();
}

@Test
public void testIsEmulatorRealNexus5() throws Exception {
    assertThat(
            DeviceUtils.isRunningOnEmulator("google/hammerhead/hammerhead:6.0.1/MMB29K/2419427:user/release-keys",
                    "hammerhead", "LGE")).isFalse();
}

...and here's our code (debug logs and comments removed for conciseness):

public static boolean isRunningOnEmulator() {
    if (sIsRunningEmulator == null) {
        sIsRunningEmulator = isRunningOnEmulator(Build.FINGERPRINT, Build.HARDWARE, Build.MANUFACTURER);
    }

    return sIsRunningEmulator;
}

static boolean isRunningOnEmulator(String fingerprint, String hardware, String manufacturer) {
    boolean isEmulatorFingerprint = fingerprint.endsWith("test-keys");
    boolean isEmulatorManufacturer = manufacturer.equals("Genymotion")
            || manufacturer.equals("unknown");

    if (isEmulatorFingerprint && isEmulatorManufacturer) {
        return true;
    } else {
        return false;
    }
}

Answer 5

How about something like the code below to tell if your app was signed with the debug key? it's not detecting the emulator but it might work for your purpose?

public void onCreate Bundle b ) {
   super.onCreate(savedInstanceState);
   if ( signedWithDebugKey(this,this.getClass()) ) {
     blah blah blah
   }

  blah 
    blah 
      blah

}

static final String DEBUGKEY = 
      "get the debug key from logcat after calling the function below once from the emulator";    


public static boolean signedWithDebugKey(Context context, Class<?> cls) 
{
    boolean result = false;
    try {
        ComponentName comp = new ComponentName(context, cls);
        PackageInfo pinfo = context.getPackageManager().getPackageInfo(comp.getPackageName(),PackageManager.GET_SIGNATURES);
        Signature sigs[] = pinfo.signatures;
        for ( int i = 0; i < sigs.length;i++)
        Log.d(TAG,sigs[i].toCharsString());
        if (DEBUGKEY.equals(sigs[0].toCharsString())) {
            result = true;
            Log.d(TAG,"package has been signed with the debug key");
        } else {
            Log.d(TAG,"package signed with a key other than the debug key");
        }

    } catch (android.content.pm.PackageManager.NameNotFoundException e) {
        return false;
    }

    return result;

} 

Answer 6

Don't know if there are better ways to detect the emu, but the emulator will have the file init.goldfish.rc in the root-directory.

It's the emulator specific startup-script, and it shouldn't be there on a non-emulator build.