Made sure the file is a .txt file. Made a basic fileReader

app/src/main/java/org/schabi/newpipe/local/bookmark/BookmarkFragment.java

@@ -1,6 +1,9 @@
 package org.schabi.newpipe.local.bookmark;
 
+import android.app.Activity;
 import android.content.DialogInterface;
+import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
 import android.os.Parcelable;
 import android.text.InputType;
@@ -11,7 +14,11 @@ import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.Toast;
 
+import androidx.activity.result.ActivityResult;
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AlertDialog;
@@ -32,6 +39,9 @@ import org.schabi.newpipe.error.UserAction;
 import org.schabi.newpipe.local.BaseLocalListFragment;
 import org.schabi.newpipe.local.playlist.LocalPlaylistManager;
 import org.schabi.newpipe.local.playlist.RemotePlaylistManager;
+import org.schabi.newpipe.streams.io.NoFileManagerSafeGuard;
+import org.schabi.newpipe.streams.io.StoredFileHelper;
+import org.schabi.newpipe.util.Constants;
 import org.schabi.newpipe.util.NavigationHelper;
 import org.schabi.newpipe.util.OnClickGesture;
 
@@ -48,6 +58,8 @@ import io.reactivex.rxjava3.disposables.Disposable;
 public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistLocalItem>, Void> {
     @State
     protected Parcelable itemsListState;
+    @State
+    int currentServiceId = Constants.NO_SERVICE_ID;
 
     private Subscription databaseSubscription;
     private CompositeDisposable disposables = new CompositeDisposable();
@@ -91,11 +103,43 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
     public boolean onOptionsItemSelected(final MenuItem item) {
         switch (item.getItemId()) {
             case R.id.import_playlist:
+                //open files app
+                NoFileManagerSafeGuard.launchSafe(
+                        requestImportFileLauncher,
+                        //make sure the selected file is a text file.
+                        StoredFileHelper.getPicker(activity, "*/*"),
+                        TAG,
+                        getContext()
+                );
+
+                //read youtube links, has more conditions
                 return true;
             default:
                 return super.onOptionsItemSelected(item);
         }
     }
+    private final ActivityResultLauncher<Intent> requestImportFileLauncher =
+            registerForActivityResult(new ActivityResultContracts.StartActivityForResult(),
+                    this::requestImportFileResult);
+    private void requestImportFileResult(final ActivityResult result) {
+        if (result.getData() == null) {
+            return;
+        }
+        final Uri uri = result.getData().getData();
+        if (result.getResultCode() == Activity.RESULT_OK && uri != null) {
+            final String mimeType = getActivity().getContentResolver().getType(uri);
+            // Check if the selected file is a text file
+            if (mimeType != null && mimeType.equals("text/plain")) {
+
+                final BookmarkImportService parser = new BookmarkImportService(uri);
+                parser.importBookmarks(activity);
+                System.out.println(parser);
+        } else {
+                Toast.makeText(getActivity(), "Please select a .txt file!",
+                        Toast.LENGTH_SHORT).show();
+            }
+        }
+        }
 
     @Override
     public void onResume() {

app/src/main/java/org/schabi/newpipe/local/bookmark/BookmarkImportService.java

@@ -0,0 +1,41 @@
+package org.schabi.newpipe.local.bookmark;
+
+import android.app.Activity;
+import android.net.Uri;
+import android.widget.Toast;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+public class BookmarkImportService {
+    private Uri textFileUri;
+    public BookmarkImportService(final Uri textFileUri) {
+        this.textFileUri = textFileUri;
+    }
+
+    public void importBookmarks(final Activity activity) {
+        if (textFileUri != null) {
+        try {
+            final InputStream inputStream =
+                    activity.getContentResolver().openInputStream(textFileUri);
+            if (inputStream != null) {
+                final BufferedReader reader =
+                        new BufferedReader(new InputStreamReader(inputStream));
+                String line;
+
+                while ((line = reader.readLine()) != null) {
+                    Toast.makeText(activity, line, Toast.LENGTH_SHORT).show();
+                }
+
+                reader.close();
+                inputStream.close();
+            }
+        } catch (final IOException e) {
+            throw new RuntimeException(e);
+        }
+        }
+    }
+
+}