"How can I detect the Android emulator?" is a question a lot of people have asked.

The authoritative way is as below. On the Android emulator, there exists the property ro.kernel.qemu. On an actual Android device, this property doesn't exist.

    public static boolean isRunningOnEmulator() {
        String emulatorProperty = SystemProperties.get("ro.kernel.qemu");
        boolean Result = (emulatorProperty!=null) && (emulatorProperty.equals("1"));
        return Result;
    } 

SystemProperties is a helper class I've created that uses Reflection to call into the public android.os.SystemProperties which is not exposed in the Android SDK.