Convertir archivo: Uri a archivo en Android

¿Cuál es la forma más fácil de convertir de file: android.net.Uria aFile en Android?

Intenté lo siguiente pero no funciona:

 final File file = new File(Environment.getExternalStorageDirectory(), "read.me");
 Uri uri = Uri.fromFile(file);
 File auxFile = new File(uri.toString());
 assertEquals(file.getAbsolutePath(), auxFile.getAbsolutePath());

Lo que quieres es ...

new File(uri.getPath());

... y no...

new File(uri.toString());

NOTA: uri.toString() devuelve una cadena en el formato: "file:///mnt/sdcard/myPicture.jpg", mientras que uri.getPath()devuelve una cadena en el formato: "/mnt/sdcard/myPicture.jpg".

Después de buscar durante mucho tiempo, esto es lo que funcionó para mí:

File file = new File(getPath(uri));


public String getPath(Uri uri) 
    {
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
        if (cursor == null) return null;
        int column_index =             cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        String s=cursor.getString(column_index);
        cursor.close();
        return s;
    }

utilizar

InputStream inputStream = getContentResolver().openInputStream(uri);    

directamente y copie el archivo. Ver también:

https://developer.android.com/guide/topics/providers/document-provider.html

EDITAR: Lo siento, debería haber probado mejor antes. Esto debería funcionar:

new File(new URI(androidURI.toString()));

URI es java.net.URI.

Mejor solución

Cree una clase FileUtil simple y úsela para crear, copiar y renombrar el archivo

Soy útil uri.toString()y uri.getPath()no trabajo para mí. Finalmente encontré esta solución.

import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.provider.OpenableColumns;
import android.util.Log;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class FileUtil {
    private static final int EOF = -1;
    private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;

    private FileUtil() {

    }

    public static File from(Context context, Uri uri) throws IOException {
        InputStream inputStream = context.getContentResolver().openInputStream(uri);
        String fileName = getFileName(context, uri);
        String[] splitName = splitFileName(fileName);
        File tempFile = File.createTempFile(splitName[0], splitName[1]);
        tempFile = rename(tempFile, fileName);
        tempFile.deleteOnExit();
        FileOutputStream out = null;
        try {
            out = new FileOutputStream(tempFile);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        if (inputStream != null) {
            copy(inputStream, out);
            inputStream.close();
        }

        if (out != null) {
            out.close();
        }
        return tempFile;
    }

    private static String[] splitFileName(String fileName) {
        String name = fileName;
        String extension = "";
        int i = fileName.lastIndexOf(".");
        if (i != -1) {
            name = fileName.substring(0, i);
            extension = fileName.substring(i);
        }

        return new String[]{name, extension};
    }

    private static String getFileName(Context context, Uri uri) {
        String result = null;
        if (uri.getScheme().equals("content")) {
            Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
            try {
                if (cursor != null && cursor.moveToFirst()) {
                    result = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if (cursor != null) {
                    cursor.close();
                }
            }
        }
        if (result == null) {
            result = uri.getPath();
            int cut = result.lastIndexOf(File.separator);
            if (cut != -1) {
                result = result.substring(cut + 1);
            }
        }
        return result;
    }

    private static File rename(File file, String newName) {
        File newFile = new File(file.getParent(), newName);
        if (!newFile.equals(file)) {
            if (newFile.exists() && newFile.delete()) {
                Log.d("FileUtil", "Delete old " + newName + " file");
            }
            if (file.renameTo(newFile)) {
                Log.d("FileUtil", "Rename file to " + newName);
            }
        }
        return newFile;
    }

    private static long copy(InputStream input, OutputStream output) throws IOException {
        long count = 0;
        int n;
        byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
        while (EOF != (n = input.read(buffer))) {
            output.write(buffer, 0, n);
            count += n;
        }
        return count;
    }
}

Use la clase FileUtil en su código

try {
         File file = FileUtil.from(MainActivity.this,fileUri);
         Log.d("file", "File...:::: uti - "+file .getPath()+" file -" + file + " : " + file .exists());

  } catch (IOException e) {
          e.printStackTrace();
  }

Nada de esto funciona para mí. Encontré que esta es la solución de trabajo. Pero mi caso es específico de las imágenes .

String[] filePathColumn = { MediaStore.Images.Media.DATA };
Cursor cursor = getActivity().getContentResolver().query(uri, filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String filePath = cursor.getString(columnIndex);
cursor.close();

Android + Kotlin

1. Agregar dependencia para las extensiones de Android Kotlin:

   implementation 'androidx.core:core-ktx:{latestVersion}'

2. Obtener archivo de uri:

   uri.toFile()

Android + Java

Solo muévete hacia arriba;)

Con Kotlin es aún más fácil:

val file = File(uri.path)

O si está utilizando extensiones de Kotlin para Android :

val file = uri.toFile()

@CommonsWare explicó todas las cosas bastante bien. Y realmente deberíamos usar la solución que él propuso.

Por cierto, solo la información en la que podemos confiar cuando hacemos consultas ContentResolveres el nombre y el tamaño de un archivo como se menciona aquí: Recuperando información de archivo | Desarrolladores de Android

Como puedes ver hay una interfaz OpenableColumns que contiene solo dos campos: DISPLAY_NAME y SIZE.

En mi caso, necesitaba recuperar información EXIF ​​sobre una imagen JPEG y rotarla si fuera necesario antes de enviarla a un servidor. Para hacer eso, copié el contenido de un archivo en un archivo temporal usando ContentResolveryopenInputStream()

Hice esto de la siguiente manera:

try {
    readImageInformation(new File(contentUri.getPath()));

} catch (IOException e) {
    readImageInformation(new File(getRealPathFromURI(context,
                contentUri)));
}

public static String getRealPathFromURI(Context context, Uri contentUri) {
        String[] proj = { MediaStore.Images.Media.DATA };
        Cursor cursor = context.getContentResolver().query(contentUri, proj,
                null, null, null);
        int column_index = cursor
                .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
}

Básicamente, primero trato de usar un archivo, es decir, una imagen tomada por la cámara y guardada en la tarjeta SD. Esto no funciona para la imagen devuelta por: Intent photoPickerIntent = new Intent (Intent.ACTION_PICK); En ese caso, es necesario convertir Uri en ruta real por getRealPathFromURI()función. Entonces, la conclusión es que depende del tipo de Uri que desee convertir a archivo.

Si tiene uno Urique se ajusta al DocumentContract, probablemente no quiera usarlo File. Si está en kotlin, use DocumentFilepara hacer cosas que usaría en el Viejo Mundo Filey use ContentResolverpara obtener transmisiones.

Todo lo demás está prácticamente garantizado para romperse.

Para este caso, especialmente en Android, el camino para los bytes suele ser más rápido.

Con esto, lo resolví estableciendo una clase FileHelperque tiene la responsabilidad de ocuparse de leer / escribir bytes desde / a un archivo a través de una secuencia y una claseUriHelper que tiene la responsabilidad de averiguar la ruta de Uri y el permiso.

Por lo que se sabe en general, string.getBytes((charset == null) ? DEFAULT_CHARSET:charset) puede ayudarnos a transferir la cadena que desea a los bytes que necesita.

Cómo permitir que UriHelper y FileHelper le copien una imagen anotada por Uri en un archivo, puede ejecutar:

FileHelper.getInstance().copy(UriHelper.getInstance().toFile(uri_of_a_picture)
                        , FileHelper.getInstance().createExternalFile(null, UriHelper.getInstance().generateFileNameBasedOnTimeStamp()
                                + UriHelper.getInstance().getFileName(uri_of_a_picture, context), context)
                );

acerca de mi UriHelper:

public class UriHelper {
private static UriHelper INSTANCE = new UriHelper();

public static UriHelper getInstance() {
    return INSTANCE;
}

@SuppressLint("SimpleDateFormat")
public String generateFileNameBasedOnTimeStamp() {
    return new SimpleDateFormat("yyyyMMdd_hhmmss").format(new Date()) + ".jpeg";
}

/**
 * if uri.getScheme.equals("content"), open it with a content resolver.
 * if the uri.Scheme.equals("file"), open it using normal file methods.
 */
//

public File toFile(Uri uri) {
    if (uri == null) return null;
    Logger.d(">>> uri path:" + uri.getPath());
    Logger.d(">>> uri string:" + uri.toString());
    return new File(uri.getPath());
}

public DocumentFile toDocumentFile(Uri uri) {
    if (uri == null) return null;
    Logger.d(">>> uri path:" + uri.getPath());
    Logger.d(">>> uri string:" + uri.toString());
    return DocumentFile.fromFile(new File(uri.getPath()));
}

public Uri toUri(File file) {
    if (file == null) return null;
    Logger.d(">>> file path:" + file.getAbsolutePath());
    return Uri.fromFile(file); //returns an immutable URI reference representing the file
}

public String getPath(Uri uri, Context context) {
    if (uri == null) return null;
    if (uri.getScheme() == null) return null;
    Logger.d(">>> uri path:" + uri.getPath());
    Logger.d(">>> uri string:" + uri.toString());
    String path;
    if (uri.getScheme().equals("content")) {
        //Cursor cursor = context.getContentResolver().query(uri, new String[] {MediaStore.Images.ImageColumns.DATA}, null, null, null);
        Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
        if (cursor == null) {
            Logger.e("!!! cursor is null");
            return null;
        }
        if (cursor.getCount() >= 0) {
            Logger.d("... the numbers of rows:" + cursor.getCount()
                        + "and the numbers of columns:" + cursor.getColumnCount());
            if (cursor.isBeforeFirst()) {
                while (cursor.moveToNext()) {
                    StringBuilder stringBuilder = new StringBuilder();
                    for (int i = 0; i<cursor.getColumnCount(); i++) {
                        stringBuilder.append("... iterating cursor.getString(" + i +"(" + cursor.getColumnName(i) + ")):" + cursor.getString(i));
                        stringBuilder.append("\n");
                    }
                    Logger.d(stringBuilder.toString());
                }
            } else {
                cursor.moveToFirst();
                do {
                    StringBuilder stringBuilder = new StringBuilder();
                    for (int i = 0; i<cursor.getColumnCount(); i++) {
                        stringBuilder.append("... iterating cursor.getString(" + i +"(" + cursor.getColumnName(i) + ")):" + cursor.getString(i));
                        stringBuilder.append("\n");
                    }
                    Logger.d(stringBuilder.toString());
                } while (cursor.moveToNext());
            }
            path = uri.getPath();
            cursor.close();
            Logger.d("... content scheme:" + uri.getScheme() + "  and return:" + path);
            return path;
        } else {
            path = uri.getPath();
            Logger.d("... content scheme:" + uri.getScheme()
                    + " but the numbers of rows in the cursor is < 0:" + cursor.getCount()
                    + "  and return:" + path);
            return path;
        }
    } else {
        path = uri.getPath();
        Logger.d("... not content scheme:" + uri.getScheme() + "  and return:" + path);
        return path;
    }
}

public String getFileName(Uri uri, Context context) {
    if (uri == null) return null;
    if (uri.getScheme() == null) return null;
    Logger.d(">>> uri path:" + uri.getPath());
    Logger.d(">>> uri string:" + uri.toString());
    String path;
    if (uri.getScheme().equals("content")) {
        //Cursor cursor = context.getContentResolver().query(uri, new String[] {MediaStore.Images.ImageColumns.DATA}, null, null, null);
        Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
        if (cursor == null) {
            Logger.e("!!! cursor is null");
            return null;
        }
        if (cursor.getCount() >= 0) {
            Logger.d("... the numbers of rows:" + cursor.getCount()
                    + "and the numbers of columns:" + cursor.getColumnCount());
            if (cursor.isBeforeFirst()) {
                while (cursor.moveToNext()) {
                    StringBuilder stringBuilder = new StringBuilder();
                    for (int i = 0; i<cursor.getColumnCount(); i++) {
                        stringBuilder.append("... iterating cursor.getString(" + i +"(" + cursor.getColumnName(i) + ")):" + cursor.getString(i));
                        stringBuilder.append("\n");
                    }
                    Logger.d(stringBuilder.toString());
                }
            } else {
                cursor.moveToFirst();
                do {
                    StringBuilder stringBuilder = new StringBuilder();
                    for (int i = 0; i<cursor.getColumnCount(); i++) {
                        stringBuilder.append("... iterating cursor.getString(" + i +"(" + cursor.getColumnName(i) + ")):" + cursor.getString(i));
                        stringBuilder.append("\n");
                    }
                    Logger.d(stringBuilder.toString());
                } while (cursor.moveToNext());
            }
            cursor.moveToFirst();
            path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.ImageColumns.DISPLAY_NAME));
            cursor.close();
            Logger.d("... content scheme:" + uri.getScheme() + "  and return:" + path);
            return path;
        } else {
            path = uri.getLastPathSegment();
            Logger.d("... content scheme:" + uri.getScheme()
                    + " but the numbers of rows in the cursor is < 0:" + cursor.getCount()
                    + "  and return:" + path);
            return path;
        }
    } else {
        path = uri.getLastPathSegment();
        Logger.d("... not content scheme:" + uri.getScheme() + "  and return:" + path);
        return path;
    }
}

}

acerca de mi FileHelper:

public class FileHelper {
private static final String DEFAULT_DIR_NAME = "AmoFromTaiwan";
private static final int DEFAULT_BUFFER_SIZE = 1024;
private static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
private static final int EOF = -1;
private static FileHelper INSTANCE = new FileHelper();

public static FileHelper getInstance() {
    return INSTANCE;
}

private boolean isExternalStorageWritable(Context context) {
    /*
    String state = Environment.getExternalStorageState();
    return Environment.MEDIA_MOUNTED.equals(state);
    */
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (context.checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
            return true;
        } else {
            Logger.e("!!! checkSelfPermission() not granted");
            return false;
        }
    } else { //permission is automatically granted on sdk<23 upon installation
        return true;
    }
}

private boolean isExternalStorageReadable(Context context) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (context.checkSelfPermission(android.Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
            return true;
        } else {
            Logger.e("!!! checkSelfPermission() not granted");
            return false;
        }
    } else { //permission is automatically granted on sdk<23 upon installation
        return true;
    }
}

@SuppressLint("SimpleDateFormat")
private String generateFileNameBasedOnTimeStamp() {
    return new SimpleDateFormat("yyyyMMdd_hhmmss").format(new Date()) + ".jpeg";
}

public File createExternalFile(String dir_name, String file_name, Context context) {
    String dir_path;
    String file_path;
    File dir ;
    File file;
    if (!isExternalStorageWritable(context)) {
        Logger.e("!!! external storage not writable");
        return null;
    }
    if (dir_name == null) {
        dir_path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).getAbsolutePath() + File.separator + DEFAULT_DIR_NAME;
    } else {
        dir_path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).getAbsolutePath() + File.separator + dir_name;
    }
    Logger.d("... going to access an external dir:" + dir_path);
    dir = new File(dir_path);
    if (!dir.exists()) {
        Logger.d("... going to mkdirs:" + dir_path);
        if (!dir.mkdirs()) {
            Logger.e("!!! failed to mkdirs");
            return null;
        }
    }
    if (file_name == null) {
        file_path = dir_path + File.separator + generateFileNameBasedOnTimeStamp();
    } else {
        file_path = dir_path + File.separator + file_name;
    }
    Logger.d("... going to return an external dir:" + file_path);
    file = new File(file_path);
    if (file.exists()) {
        Logger.d("... before creating to delete an external dir:" + file.getAbsolutePath());
        if (!file.delete()) {
            Logger.e("!!! failed to delete file");
            return null;
        }
    }
    return file;
}

public File createInternalFile(String dir_name, String file_name, Context context) {
    String dir_path;
    String file_path;
    File dir ;
    File file;
    if (dir_name == null) {
        dir = new ContextWrapper(context).getDir(DEFAULT_DIR_NAME, Context.MODE_PRIVATE);
    } else {
        dir = new ContextWrapper(context).getDir(dir_name, Context.MODE_PRIVATE);
    }
    dir_path = dir.getAbsolutePath();
    Logger.d("... going to access an internal dir:" + dir_path);
    if (!dir.exists()) {
        Logger.d("... going to mkdirs:" + dir_path);
        if (!dir.mkdirs()) {
            Logger.e("!!! mkdirs failed");
            return null;
        }
    }
    if (file_name == null) {
        file = new File(dir, generateFileNameBasedOnTimeStamp());
    } else {
        file = new File(dir, file_name);
    }
    file_path = file.getAbsolutePath();
    Logger.d("... going to return an internal dir:" + file_path);
    if (file.exists()) {
        Logger.d("... before creating to delete an external dir:" + file.getAbsolutePath());
        if (!file.delete()) {
            Logger.e("!!! failed to delete file");
            return null;
        }
    }
    return file;
}

public File getExternalFile(String dir_name, String file_name, Context context) {
    String dir_path;
    String file_path;
    File file;
    if (!isExternalStorageWritable(context)) {
        Logger.e("!!! external storage not writable");
        return null;
    }
    if (dir_name == null) {
        dir_path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).getAbsolutePath() + File.separator + DEFAULT_DIR_NAME;
    } else {
        dir_path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).getAbsolutePath() + File.separator + dir_name;
    }
    if (file_name == null) {
        file_path = dir_path;
    } else {
        file_path = dir_path + File.separator + file_name;
    }
    Logger.d("... going to return an external file:" + file_path);
    file = new File(file_path);
    if (file.exists()) {
        Logger.d("... file exists:" + file.getAbsolutePath());
    } else {
        Logger.e("!!! file does't exist:" + file.getAbsolutePath());
    }
    return file;
}

public File getInternalFile(String dir_name, String file_name, Context context) {
    String file_path;
    File dir ;
    File file;
    if (dir_name == null) {
        dir = new ContextWrapper(context).getDir(DEFAULT_DIR_NAME, Context.MODE_PRIVATE);
    } else {
        dir = new ContextWrapper(context).getDir(dir_name, Context.MODE_PRIVATE);
    }
    if (file_name == null) {
        file = new File(dir.getAbsolutePath());
    } else {
        file = new File(dir, file_name);
    }
    file_path = file.getAbsolutePath();
    Logger.d("... going to return an internal dir:" + file_path);
    if (file.exists()) {
        Logger.d("... file exists:" + file.getAbsolutePath());
    } else {
        Logger.e("!!! file does't exist:" + file.getAbsolutePath());
    }
    return file;
}

private byte[] readBytesFromFile(File file) {
    Logger.d(">>> path:" + file.getAbsolutePath());
    FileInputStream fis;
    long file_length;
    byte[] buffer;
    int offset = 0;
    int next = 0;
    if (!file.exists()) {
        Logger.e("!!! file doesn't exists");
        return null;
    }
    if (file.length() > Integer.MAX_VALUE) {
        Logger.e("!!! file length is out of max of int");
        return null;
    } else {
        file_length = file.length();
    }
    try {
        fis = new FileInputStream(file);
        //buffer = new byte[(int) file_length];
        buffer = new byte[(int) file.length()];
        long time_start = System.currentTimeMillis();
        while (true) {
            Logger.d("... now next:" + next + " and offset:" + offset);
            if (System.currentTimeMillis() - time_start > 1000) {
                Logger.e("!!! left due to time out");
                break;
            }
            next = fis.read(buffer, offset, (buffer.length-offset));
            if (next < 0 || offset >= buffer.length) {
                Logger.d("... completed to read");
                break;
            }
            offset += next;
        }
        //if (offset < buffer.length) {
        if (offset < (int) file_length) {
            Logger.e("!!! not complete to read");
            return null;
        }
        fis.close();
        return buffer;
    } catch (IOException e) {
        e.printStackTrace();
        Logger.e("!!! IOException");
        return null;
    }
}

public byte[] readBytesFromFile(File file, boolean is_fis_fos_only) {
    if (file == null) return null;
    if (is_fis_fos_only) {
        return readBytesFromFile(file);
    }
    Logger.d(">>> path:" + file.getAbsolutePath());
    FileInputStream fis;
    BufferedInputStream bis;
    ByteArrayOutputStream bos;
    byte[] buf = new byte[(int) file.length()];
    int num_read;
    if (!file.exists()) {
        Logger.e("!!! file doesn't exists");
        return null;
    }
    try {
        fis = new FileInputStream(file);
        bis = new BufferedInputStream(fis);
        bos = new ByteArrayOutputStream();
        long time_start = System.currentTimeMillis();
        while (true) {
            if (System.currentTimeMillis() - time_start > 1000) {
                Logger.e("!!! left due to time out");
                break;
            }
            num_read = bis.read(buf, 0, buf.length); //1024 bytes per call
            if (num_read < 0) break;
            bos.write(buf, 0, num_read);
        }
        buf = bos.toByteArray();
        fis.close();
        bis.close();
        bos.close();
        return buf;
    } catch (FileNotFoundException e) {
        e.printStackTrace();
        Logger.e("!!! FileNotFoundException");
        return null;
    } catch (IOException e) {
        e.printStackTrace();
        Logger.e("!!! IOException");
        return null;
    }
}

/**
 * streams (InputStream and OutputStream) transfer binary data
 * if to write a string to a stream, must first convert it to bytes, or in other words encode it
 */
public boolean writeStringToFile(File file, String string, Charset charset) {
    if (file == null) return false;
    if (string == null) return false;
    return writeBytesToFile(file, string.getBytes((charset == null) ? DEFAULT_CHARSET:charset));
}

public boolean writeBytesToFile(File file, byte[] data) {
    if (file == null) return false;
    if (data == null) return false;
    FileOutputStream fos;
    BufferedOutputStream bos;
    try {
        fos = new FileOutputStream(file);
        bos = new BufferedOutputStream(fos);
        bos.write(data, 0, data.length);
        bos.flush();
        bos.close();
        fos.close();
    } catch (IOException e) {
        e.printStackTrace();
        Logger.e("!!! IOException");
        return false;
    }
    return true;
}

/**
 * io blocks until some input/output is available.
 */
public boolean copy(File source, File destination) {
    if (source == null || destination == null) return false;
    Logger.d(">>> source:" + source.getAbsolutePath() + ", destination:" + destination.getAbsolutePath());
    try {
        FileInputStream fis = new FileInputStream(source);
        FileOutputStream fos = new FileOutputStream(destination);
        byte[] buffer = new byte[(int) source.length()];
        int len;
        while (EOF != (len = fis.read(buffer))) {
            fos.write(buffer, 0, len);
        }
        if (true) { //debug
            byte[] copies = readBytesFromFile(destination);
            if (copies != null) {
                int copy_len = copies.length;
                Logger.d("... stream read and write done for " + copy_len + " bytes");
            }
        }
        return destination.length() != 0;
    } catch (IOException e) {
        e.printStackTrace();
        return false;
    }
}

public void list(final String path, final String end, final List<File> files) {
    Logger.d(">>> path:" + path + ", end:" + end);
    File file = new File(path);
    if (file.isDirectory()) {
        for (File child : file.listFiles()){
            list(child.getAbsolutePath(), end, files);
        }
    } else if (file.isFile()) {
        if (end.equals("")) {
            files.add(file);
        } else {
            if (file.getName().endsWith(end)) files.add(file);
        }
    }
}

public String[] splitFileName(File file, String split) {
    String path;
    String ext;
    int lastIndexOfSplit = file.getAbsolutePath().lastIndexOf(split);
    if (lastIndexOfSplit < 0) {
        path = file.getAbsolutePath();
        ext = "";
    } else {
        path = file.getAbsolutePath().substring(0, lastIndexOfSplit);
        ext = file.getAbsolutePath().substring(lastIndexOfSplit);
    }
    return new String[] {path, ext};
}

public File rename(File old_file, String new_name) {
    if (old_file == null || new_name == null) return null;
    Logger.d(">>> old file path:" + old_file.getAbsolutePath() + ", new file name:" + new_name);
    File new_file = new File(old_file, new_name);
    if (!old_file.equals(new_file)) {
        if (new_file.exists()) { //if find out previous file/dir at new path name exists
            if (new_file.delete()) {
                Logger.d("... succeeded to delete previous file at new abstract path name:" + new_file.getAbsolutePath());
            } else {
                Logger.e("!!! failed to delete previous file at new abstract path name");
                return null;
            }
        }
        if (old_file.renameTo(new_file)) {
            Logger.d("... succeeded to rename old file to new abstract path name:" + new_file.getAbsolutePath());
        } else {
            Logger.e("!!! failed to rename old file to new abstract path name");
        }
    } else {
        Logger.d("... new and old file have the equal abstract path name:" + new_file.getAbsolutePath());
    }
    return new_file;
}

public boolean remove(final String path, final String end) {
    Logger.d(">>> path:" + path + ", end:" + end);
    File file = new File(path);
    boolean result = false;
    if (file.isDirectory()) {
        for (File child : file.listFiles()){
            result = remove(child.getAbsolutePath(), end);
        }
    } else if (file.isFile()) {
        if (end.equals("")) {
            result = file.delete();
        } else {
            if (file.getName().endsWith(end)) result = file.delete();
        }
    } else {
        Logger.e("!!! child is not file or directory");
    }
    return result;
}

@TargetApi(Build.VERSION_CODES.O)
public byte[] readNIOBytesFromFile(String path) throws IOException {
    Logger.d(">>> path:" + path);
    if (!Files.exists(Paths.get(path), LinkOption.NOFOLLOW_LINKS)) {
        Logger.e("!!! file doesn't exists");
        return null;
    } else {
        return Files.readAllBytes(Paths.get(path));
    }
}

@TargetApi(Build.VERSION_CODES.O)
public File writeNIOBytesToFile(String dir, String name, byte[] data) {
    Logger.d(">>> dir:" + dir + ", name:" + name);
    Path path_dir;
    Path path_file;
    try {
        if (!Files.exists(Paths.get(dir), LinkOption.NOFOLLOW_LINKS)) {
            Logger.d("... make a dir");
            path_dir = Files.createDirectories(Paths.get(dir));
            if (path_dir == null) {
                Logger.e("!!! failed to make a dir");
                return null;
            }
        }
        path_file = Files.write(Paths.get(name), data);
        return path_file.toFile();
    } catch (IOException e) {
        e.printStackTrace();
        Logger.e("!!! IOException");
        return null;
    }
}

@TargetApi(Build.VERSION_CODES.O)
public void listNIO(final String dir, final String end, final List<File> files) throws IOException {
    Logger.d(">>> dir:" + dir + ", end:" + end);
    Files.walkFileTree(Paths.get(dir), new FileVisitor<Path>() {
        @Override
        public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
            Logger.d("... file:" + dir.getFileName());
            return FileVisitResult.CONTINUE;
        }

        @Override
        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
            Logger.d("... file:" + file.getFileName());
            if (end.equals("")) {
                files.add(file.toFile());
            } else {
                if (file.endsWith(end)) files.add(file.toFile());
            }
            return FileVisitResult.CONTINUE;
        }

        @Override
        public FileVisitResult visitFileFailed(Path file, IOException exc) {
            Logger.d("... file:" + file.getFileName());
            if (end.equals("")) {
                files.add(file.toFile());
            } else {
                if (file.endsWith(end)) files.add(file.toFile());
            }
            return FileVisitResult.CONTINUE;
        }

        @Override
        public FileVisitResult postVisitDirectory(Path dir, IOException exc) {
            Logger.d("... file:" + dir.getFileName());
            return FileVisitResult.CONTINUE;
        }
    });
}

/**
 * recursion
 */
private int factorial (int x) {
    if (x > 1) return (x*(factorial(x-1)));
    else if (x == 1) return x;
    else return 0;
}

}

Para las personas que están buscando una solución para imágenes en particular, aquí está.

private Bitmap getBitmapFromUri(Uri contentUri) {
        String path = null;
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = getContentResolver().query(contentUri, projection, null, null, null);
        if (cursor.moveToFirst()) {
            int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            path = cursor.getString(columnIndex);
        }
        cursor.close();
        Bitmap bitmap = BitmapFactory.decodeFile(path);
        return bitmap;
    }

Archivo imageToUpload = nuevo archivo (nuevo URI (androidURI.toString ())); funciona si este es un archivo que ha creado en el almacenamiento externo.

Por ejemplo, archivo: /// storage / emulated / 0 / (algún directorio y nombre de archivo)

public String getRealPathFromURI (Uri uri) {

    String result;
    Cursor cursor = getContentResolver().query(uri, null, null, null, null);
    if (cursor == null) {
        result = uri.getPath();
        cursor.close();
        return result;
    }
    cursor.moveToFirst();
    int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
    result = cursor.getString(idx);
    cursor.close();
    return result;
}

Luego, para obtener el archivo de URI:

        File finalFile = newFile(getRealPathFromURI(uri));

- LA ESPERANZA PUEDE AYUDARTE ----

Mediante el siguiente código, puedo obtener el archivo pdf compartido de la aplicación de Adobe como flujo y guardarlo en la ruta de la aplicación de Android

Android.Net.Uri fileuri =
    (Android.Net.Uri)Intent.GetParcelableExtra(Intent.ExtraStream);

    fileuri i am getting as {content://com.adobe.reader.fileprovider/root_external/
                                        data/data/com.adobe.reader/files/Downloads/sample.pdf}

    string filePath = fileuri.Path;

   filePath I am gettings as root_external/data/data/com.adobe.reader/files/Download/sample.pdf

      using (var stream = ContentResolver.OpenInputStream(fileuri))
      {
       byte[] fileByteArray = ToByteArray(stream); //only once you can read bytes from stream second time onwards it has zero bytes

       string fileDestinationPath ="<path of your destination> "
       convertByteArrayToPDF(fileByteArray, fileDestinationPath);//here pdf copied to your destination path
       }
     public static byte[] ToByteArray(Stream stream)
        {
            var bytes = new List<byte>();

            int b;
            while ((b = stream.ReadByte()) != -1)
                bytes.Add((byte)b);

            return bytes.ToArray();
        }

      public static string convertByteArrayToPDF(byte[] pdfByteArray, string filePath)
        {

            try
            {
                Java.IO.File data = new Java.IO.File(filePath);
                Java.IO.OutputStream outPut = new Java.IO.FileOutputStream(data);
                outPut.Write(pdfByteArray);
                return data.AbsolutePath;

            }
            catch (System.Exception ex)
            {
                return string.Empty;
            }
        }

Base de extensión en @Jacek Kwiecień respuesta para convertir uri de imagen a archivo

fun Uri.toImageFile(context: Context): File? {
    val filePathColumn = arrayOf(MediaStore.Images.Media.DATA)
    val cursor = context.contentResolver.query(this, filePathColumn, null, null, null)
    if (cursor != null) {
        if (cursor.moveToFirst()) {
            val columnIndex = cursor.getColumnIndex(filePathColumn[0])
            val filePath = cursor.getString(columnIndex)
            cursor.close()
            return File(filePath)
        }
        cursor.close()
    }
    return null
}

Si usamos File(uri.getPath()), no funcionará

Si usamos la extensión de android-ktx , todavía no funciona porque https://github.com/android/android-ktx/blob/master/src/main/java/androidx/core/net/Uri.kt

Agregar onActivityResult, obtener docx o archivo pdf

var imageUriPath = ""
imageUriPath =
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
    val split = (imageUri.path ? : "").split(":") //split the path.
    split[1]
  } else {
    imageUri.path ? : ""
  }
val file = File(imageUriPath)