implementing onbackpressed in android

Question

i have activity1 takes me to activity2 that takes me to fragment. i would like from fragment to go back to activity2

public void onBackPressed() {
    Intent intent = new Intent(Intent.ACTION_MAIN);
    intent.addCategory(Intent.CATEGORY_HOME);
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
}

Answer 1

While adding fragment from activity2 add it to backstack like this

getSupportFragmentManager().beginTransaction()
                           .replace(R.id.frame_layout, new SampleFragment())
                           .addToBackStack(SampleFragment.class.getSimpleName())
                           .commit();

And onBackPressed check if the fragment is present in backstack and pop it

 @Override
public void onBackPressed() {
    if(getSupportFragmentManager().getBackStackEntryCount()>0){
        Fragment fragment=getSupportFragmentManager().findFragmentById(R.id.YOUR_FRAME_LAYOUT_ID);
        if(fragment!=null && fragment.getClass().getSimpleName().equalsIgnoreCase(SampleFragment.class.getSimpleName())){
            getSupportFragmentManager().popBackStackImmediate();
        }
    }else {
        super.onBackPressed();
    }
}