Java how to come from 2nd fragment to first fragment android

To navigate from a second fragment to the first fragment in an Android app, you can use the FragmentManager and FragmentTransaction classes to pop the second fragment from the back stack.

Here is an example of how you can navigate from the second fragment to the first fragment by clicking a button:

public class SecondFragment extends Fragment {

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_layout, container, false);

    // find the back button and set an OnClickListener
    Button backButton = view.findViewById(R.id.back_button);
    backButton.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        // get the FragmentManager and start a FragmentTransaction
        FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

        // pop the second fragment from the back stack
        fragmentManager.popBackStack();

        // commit the transaction
        fragmentTransaction.commit();
      }
    });

    return view;
  }
}

This code defines a SecondFragment class that extends the Fragment class, and sets an OnClickListener for a back button in the fragment's layout. When the button is clicked, the code gets the FragmentManager object for the current activity and starts a FragmentTransaction. Then, it calls the popBackStack method to remove the second fragment from the back stack, and finally, it commits the transaction.

Note that you will need to import the necessary classes and handle any exceptions that might be thrown. You may also need to add the second fragment to the back stack when you navigate to it from the first fragment, using the addToBackStack method of the FragmentTransaction object.