How to move a non media file from /storage/emulated/0/Download to getExternalFilesDir()

Question

I created a app able to download the non media file. Now I plan to extend the app to move the downloaded file (filetype=map). I'm using compileSdkVersion 29 and targetSdkVersion 29. This https://developer.android.com/training/data-storage say's I have to use "Storage Access Framework". I used the snipped from here "How to list all pdf files on android 10?" but it does only work for media files (uri to file). Does anybody know where to find a working snipped?

Answer 1

What has to be changed in the following code in order to copy a file like "whatever.map"? The important part of the question is the file type "map" which means it is a non media file and the mime type is unknown. The target sdk has to be 29. When I - with the following code - pick a file like "whatever.png" it works. But renaming the file "whatever.map" to "whatever.png" before copy in /storage/emulated/0/Download is also not possible with target sdk 29.

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/open_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="104dp"
        android:layout_marginTop="144dp"
        android:onClick="openFile"

        android:text="Select"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/save_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="188dp"
        android:layout_marginTop="280dp"
        android:onClick="saveFile"
        android:text="Copy"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toEndOf="@+id/open_button"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

package org.hagerti.storagedemo;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import android.app.Activity;
import android.content.Intent;
import android.icu.text.SimpleDateFormat;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.channels.FileChannel;
import java.util.Date;

public class MainActivity extends AppCompatActivity {

    final static String className = MainActivity.class.getSimpleName();
    private static final int CREATE_REQUEST_CODE = 40;
    private static final int OPEN_REQUEST_CODE = 41;
    private static final int SAVE_REQUEST_CODE = 42;
    final private static String myMimeType = "image/png";
    //final private static String myMimeType = "text/map";

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Uri currentUri = null;
        if (resultCode == Activity.RESULT_OK) {
            if (requestCode == SAVE_REQUEST_CODE) {
                if (data != null) {
                    currentUri = data.getData();
                    writeFileContent(currentUri);
                }
            } else if (requestCode == OPEN_REQUEST_CODE) {

                if (data != null) {
                    currentUri = data.getData();

                    try {
                        String content = readFileContent(currentUri);
                    } catch (IOException e) {
                    }
                }
            }

        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    }

    public void openFile(View view) {
        Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType(myMimeType);
        startActivityForResult(intent, OPEN_REQUEST_CODE);
        /**
         * http://www.iana.org/assignments/media-types/media-types.xhtml
         * Often used media types:
         * image/jpeg
         * audio/mpeg4-generic
         * text/html
         * audio/mpeg
         * audio/aac
         * audio/wav
         * audio/ogg
         * audio/midi
         * audio/x-ms-wma
         * video/mp4
         * video/x-msvideo
         * video/x-ms-wmv
         * image/png
         * image/jpeg
         * image/gif
         * .xml ->text/xml
         * .txt -> text/plain
         * .cfg -> text/plain
         * .csv -> text/plain
         * .conf -> text/plain
         * .rc -> text/plain
         * .htm -> text/html
         * .html -> text/html
         * .pdf -> application/pdf
         * .apk -> application/vnd.android.package-archive
         */
    }

    private String readFileContent(Uri uri) throws IOException {
        Log.e(className, " readFileContent uri.getPath()=" + uri.getPath());
        InputStream inputStream =
                getContentResolver().openInputStream(uri);
        BufferedReader reader =
                new BufferedReader(new InputStreamReader(inputStream));
        StringBuilder stringBuilder = new StringBuilder();
        String currentline;
        while ((currentline = reader.readLine()) != null) {
            stringBuilder.append(currentline + "\n");
        }
        inputStream.close();
        return stringBuilder.toString();
    }

    public void saveFile(View view) {
        Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        //intent.setType("text/plain");
        intent.setType(myMimeType);
        startActivityForResult(intent, SAVE_REQUEST_CODE);
    }

    private void writeFileContent(Uri uri) {
        Log.e(className, " writeFileContent uri.getPath()=" + uri.getPath());
        FileChannel inChannel = null;
        FileChannel outChannel = null;
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        File expFile = new File("/storage/emulated/0/Android/data/org.hagerti.storagedemo/files" + File.separator + timeStamp + ".map");

        try {

            inChannel = new FileInputStream(getContentResolver().openFileDescriptor(uri, "r").getFileDescriptor()).getChannel();
            outChannel = new FileOutputStream(expFile).getChannel();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        try {
            inChannel.transferTo(0, inChannel.size(), outChannel);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (inChannel != null)
                try {
                    inChannel.close();
                    Log.e(className, " writeFileContent inChannel closed");
                } catch (IOException e) {
                    e.printStackTrace();
                }
            if (outChannel != null)
                try {
                    outChannel.close();
                    Log.e(className, " writeFileContent outChannel closed");
                } catch (IOException e) {
                    e.printStackTrace();
                }
        }
    }

}