Android Full Project of Fragement in java

package tech.softbinarycrunch.realvideoeditor;
import android.Manifest;
import android.content.ContentUris;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.provider.MediaStore;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import com.karumi.dexter.Dexter;
import com.karumi.dexter.MultiplePermissionsReport;
import com.karumi.dexter.PermissionToken;
import com.karumi.dexter.listener.DexterError;
import com.karumi.dexter.listener.PermissionRequest;
import com.karumi.dexter.listener.PermissionRequestErrorListener;
import com.karumi.dexter.listener.multi.MultiplePermissionsListener;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button bt=new Button(getApplicationContext());
        bt.setText("Choose video");
        RelativeLayout.LayoutParams rlpbtn=new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
        rlpbtn.addRule(RelativeLayout.CENTER_IN_PARENT);
        bt.setLayoutParams(rlpbtn);
        RelativeLayout rl=findViewById(R.id.layoutmain);
        rl.addView(bt);
        listener(bt);
        requestMultiplePermissions();
    }
    private void listener(Button bt){
        bt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                listoffile();
            }
        });
    }
    private void listoffile(){
        videoinfo();
    }
    class Video {
        private final Uri uri;
        private final String name;
        private final int duration;
        private final int size;

        public Video(Uri uri, String name, int duration, int size) {
            this.uri = uri;
            this.name = name;
            this.duration = duration;
            this.size = size;
        }
    }
    private void videoinfo(){
        List<Video> videoList = new ArrayList<>();

        Uri collection;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            collection = MediaStore.Video.Media.getContentUri(MediaStore.VOLUME_EXTERNAL);
        } else {
            collection = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
        }

        String[] projection = new String[] {
                MediaStore.Video.Media._ID,
                MediaStore.Video.Media.DISPLAY_NAME,
                MediaStore.Video.Media.DURATION,
                MediaStore.Video.Media.SIZE
        };
        String selection = MediaStore.Video.Media.DURATION +
                " >= ?";
        String[] selectionArgs = new String[] {
                String.valueOf(TimeUnit.MILLISECONDS.convert(5, TimeUnit.MINUTES))
        };
        String sortOrder = MediaStore.Video.Media.DISPLAY_NAME + " ASC";

        try (Cursor cursor = getApplicationContext().getContentResolver().query(
                collection,
                null,
                // projection,
                null,
                null,
                null
                //sortOrder
        )) {

            int idColumn = cursor.getColumnIndexOrThrow(MediaStore.Video.Media._ID);
            int nameColumn =
                    cursor.getColumnIndexOrThrow(MediaStore.Video.Media.DISPLAY_NAME);
            int durationColumn =
                    cursor.getColumnIndexOrThrow(MediaStore.Video.Media.DURATION);
            int sizeColumn = cursor.getColumnIndexOrThrow(MediaStore.Video.Media.SIZE);
            while (cursor.moveToNext()) {
                long id = cursor.getLong(idColumn);
                String name = cursor.getString(nameColumn);
                int duration = cursor.getInt(durationColumn);
                int size = cursor.getInt(sizeColumn);
                Uri contentUri = ContentUris.withAppendedId(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, id);
                videoList.add(new Video(contentUri, name, duration, size));
            }
            uploadfrag(videoList);
        }
    }
    private void uploadfrag(List<Video> video){
        Filemanager fm=new Filemanager();
        getSupportFragmentManager().beginTransaction().replace(R.id.layoutmain, fm).addToBackStack( "tag" ).setReorderingAllowed(true).commit();
    }
    private void message(String s){
        new Handler(getApplicationContext().getMainLooper()).post(new Runnable() {
            @Override
            public void run() {
                Toast.makeText(getApplicationContext(),s,Toast.LENGTH_LONG).show();
            }
        });
    }
    private void  requestMultiplePermissions(){
        Dexter.withActivity(this)
                .withPermissions(
                        Manifest.permission.WRITE_EXTERNAL_STORAGE,
                        Manifest.permission.READ_EXTERNAL_STORAGE)
                .withListener(new MultiplePermissionsListener() {
                    @Override
                    public void onPermissionsChecked(MultiplePermissionsReport report) {
                        if (report.areAllPermissionsGranted()) {
                            Toast.makeText(getApplicationContext(), "All permissions are granted by user!", Toast.LENGTH_SHORT).show();
                        }
                        if (report.isAnyPermissionPermanentlyDenied()) {

                        }
                    }

                    @Override
                    public void onPermissionRationaleShouldBeShown(List<PermissionRequest> permissions, PermissionToken token) {
                        token.continuePermissionRequest();
                    }
                }).
                withErrorListener(new PermissionRequestErrorListener() {
                    @Override
                    public void onError(DexterError error) {
                        Toast.makeText(getApplicationContext(), "Some Error! ", Toast.LENGTH_SHORT).show();
                    }
                })
                .onSameThread()
                .check();
    }
}

package tech.softbinarycrunch.realvideoeditor;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.RelativeLayout;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.Lifecycle;
import androidx.lifecycle.LifecycleOwner;
import androidx.lifecycle.LiveData;
import androidx.lifecycle.ViewModelProvider;
import androidx.lifecycle.ViewModelStore;

public class Filemanager extends Fragment {
    ViewGroup vv;
    @NonNull
    @Override
    public Lifecycle getLifecycle() {
        return super.getLifecycle();
    }

    @NonNull
    @Override
    public LifecycleOwner getViewLifecycleOwner() {
        return super.getViewLifecycleOwner();
    }

    @NonNull
    @Override
    public LiveData<LifecycleOwner> getViewLifecycleOwnerLiveData() {
        return super.getViewLifecycleOwnerLiveData();
    }

    @NonNull
    @Override
    public ViewModelStore getViewModelStore() {
        return super.getViewModelStore();
    }

    @NonNull
    @Override
    public ViewModelProvider.Factory getDefaultViewModelProviderFactory() {
        return super.getDefaultViewModelProviderFactory();
    }

    public Filemanager() {
        super();
    }

    public Filemanager(int contentLayoutId) {
        super(contentLayoutId);
    }

    @Override
    public void startActivity(Intent intent) {
        super.startActivity(intent);
    }

    @Override
    public void startActivity(Intent intent, @Nullable Bundle options) {
        super.startActivity(intent, options);
    }

    @Override
    public void onStart() {
        super.onStart();
    }

    @Override
    public void onResume() {
        super.onResume();
    }

    @Override
    public void onPause() {
        super.onPause();
    }

    @Override
    public void onStop() {
        super.onStop();
    }

    @Override
    public void onLowMemory() {
        super.onLowMemory();
    }

    @Override
    public void onDestroyView() {
        super.onDestroyView();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        container.removeAllViews();
        View v = inflater.inflate(R.layout.mainlyout,container, false);
        v.setBackgroundColor(Color.BLUE);
        return v;
    }
    private void layout(ViewGroup v){
RelativeLayout rl=new RelativeLayout(getContext());
rl.setBackgroundColor(Color.RED);
RelativeLayout.LayoutParams rlp=new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT,RelativeLayout.LayoutParams.MATCH_PARENT);
rl.setLayoutParams(rlp);
v.addView(rl);
Button bt=new Button(getContext());
bt.setText("wow");
RelativeLayout.LayoutParams rlbtn=new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
bt.setLayoutParams(rlbtn);
v.addView(bt);

    }
    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
         vv = (ViewGroup) view;
         layout(vv);
    }
    @Override
    public void onDetach() {
        super.onDetach();
    }
}

<?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="?android:windowBackground"
        android:clickable="true"
        android:id="@+id/layoutmain"
        tools:context=".MainActivity">
    </RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="?android:windowBackground"
    android:id="@+id/mainlayout">


</RelativeLayout>