How to get unique device hardware id in Android?

How to get the unique device ID in Android which cannot
be changed when performing a phone reset or OS update?

Answer

Update: 19
-11-2019

The below answer is no
more relevant to present day.

So for any one
looking for answers you should look at the documentation linked
below

href="https://developer.android.com/training/articles/user-data-ids" rel="nofollow
noreferrer">https://developer.android.com/training/articles/user-data-ids

/>

Old Answer - Not
relevant now.
You check this blog in the link
below

href="http://android-developers.blogspot.in/2011/03/identifying-app-installations.html"
rel="nofollow
noreferrer">http://android-developers.blogspot.in/2011/03/identifying-app-installations.html

ANDROID_ID

import
            android.provider.Settings.Secure;


private String
            android_id = Secure.getString(getContext().getContentResolver(),

            Secure.ANDROID_ID);
            

The above is from the
link @ href="https://stackoverflow.com/questions/2785485/is-there-a-unique-android-device-id/2853253#2853253">Is
there a unique Android device ID?

More
specifically, Settings.Secure.ANDROID_ID. This is a 64-bit quantity that is generated
and stored when the device first boots. It is reset when the device is
wiped.

ANDROID_ID
seems a good choice for a unique device identifier. There are downsides:
First, it is not 100% reliable on releases of Android prior to 2.2 (“Froyo”). Also,
there has been at least one widely-observed bug in a popular handset from a major
manufacturer, where every instance has the same
ANDROID_ID.

The below solution is not
a good one coz the value survives device wipes (“Factory resets”) and thus
you could end up making a nasty mistake when one of your customers wipes their device
and passes it on to another
person.

You get the imei number
of the device using the below

            TelephonyManager telephonyManager =
            (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);

            telephonyManager.getDeviceId();

href="http://developer.android.com/reference/android/telephony/TelephonyManager.html#getDeviceId%28%29"
rel="nofollow
noreferrer">http://developer.android.com/reference/android/telephony/TelephonyManager.html#getDeviceId%28%29

Add
this is
manifest

            android:name="android.permission.READ_PHONE_STATE"/>