How to find last activity from which current activity is opened in android?

You might want to add extras to the intent you use to start the activity to indicate where the intent is coming from or what the request is.

For example:

Intent intent = new Intent(this, OtherActivity.class);
intent.putExtra("caller", "MainActivity");
startActivity(intent);

and then your OtherActivity could detect the “caller” in its onCreate:

String caller     = getIntent().getStringExtra("caller");
Class callerClass = Class.forName(caller);