Android 打开文件 ACTION_GET_CONTENT 导致不同的 URI

Question

我正在尝试使用 Intent.ACTION_GET_CONTENT 打开文件。

根据 Android version/device 品牌文件浏览器打开，我得到以下结果：

从Downloads中选择一个文件：

content://com.android.providers.downloads.documents/document/446

正在从 Fotos 中选择一个文件：

content://media/external/images/media/309

正在从 FileCommander 中选择一个文件：

file:///storage/emulated/0/DCIM/Camera/20141027_132114.jpg

我可以打开所有这些文件，除非我尝试从 Downloads,、Audio、Afbeeldingen（图片）

打开文件

我可能无法处理这种 Uri: content://com.android.providers.downloads.documents/document/446

我试过以下方法：

正在尝试通过 new File(uri.getPath()) 打开文件。 File.exists() returns 错误。
正在尝试通过 getContext().getContentResolver().openInputStream(uri) open/reach 文件。结果变成 FileNotFoundException

正在尝试使用以下代码打开文件:

public static String getRealPathFromURI_API19(Context context, Uri uri) {

Log.i("uri", uri.getPath());
String filePath = "";
if (uri.getScheme().equals("file")) {
    return uri.getPath();
} else if (DocumentsContract.isDocumentUri(context, uri)) {
    String wholeID = DocumentsContract.getDocumentId(uri);
    Log.i("wholeID", wholeID);
    // Split at colon, use second item in the array
    String[] splits = wholeID.split(":");
if (splits.length == 2) {
    String id = splits[1];

        String[] column = {MediaStore.Images.Media.DATA};
    // where id is equal to
        String sel = MediaStore.Images.Media._ID + "=?";
        Cursor cursor = context.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                column, sel, new String[]{id}, null);
        int columnIndex = cursor.getColumnIndex(column[0]);
        if (cursor.moveToFirst()) {
            filePath = cursor.getString(columnIndex);
        }
        cursor.close();
    }
} else {
    filePath = AttachmentUtils.getPath(context, uri);
}
return filePath;
}

我做错了什么？

更新：我注意到屏幕截图中列出的文件实际上并不存在于存储中。我使用的设备是该公司的平板电脑，其中包含垃圾数据。我的同事告诉我，此设备曾与另一个 Google 帐户关联。这些文件可能是以前帐户中的文件，它们不再是 existing/reachable。

我自己的结论是我在 Android 中遇到了一些错误。我的 bug report

2017 年 2 月 6 日更新：

Android 禁止 file:// URI。请考虑考虑。

Ban on file: Uri Scheme The biggest compatibility issue so far with Android 7.0 is that the file: scheme for Uri values is banned, in effect. If you attempt to pass a file: Uri in an Intent that is going to another app — whether via an extra or as the “data” facet of the Intent — you will crash with a FileUriExposedException exception. You will face similar issues with putting file: Uri values on the clipboard in ClipData . This is coming from an updated edition of StrictMode . StrictMode.VmPolicy.Builder has a penaltyDeathOnFileUriExposure() method that triggers the detection of file: Uri values and the resulting FileUriExposedException exceptions. And, it appears that this is pre-configured, much as how StrictMode is pre-configured to apply penaltyDeathOnNetwork() (the source of your NetworkOnMainThreadException crashes).

Answer 1

使用下面的 code.This 肯定有效。

public static String getPath(Context context, Uri uri) {

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        // DocumentProvider
        if (DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }
                // TODO handle non-primary volumes
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {
                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];
                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }
                final String selection = "_id=?";
                final String[] selectionArgs = new String[]{split[1]};
                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        }
    }
    // MediaStore (and general)
    else if ("content".equalsIgnoreCase(uri.getScheme())) {
        // Return the remote address
        if (isGooglePhotosUri(uri))
            return uri.getLastPathSegment();
        return getDataColumn(context, uri, null, null);
    }
    // File
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }
    return null;
}

public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
    Cursor cursor = null;
    final String column = "_data";
    final String[] projection = {column};
    try {
        cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
        if (cursor != null && cursor.moveToFirst()) {
            final int index = cursor.getColumnIndexOrThrow(column);
            return cursor.getString(index);
        }
    } finally {
        if (cursor != null)
            cursor.close();
    }
    return null;
}

public static boolean isExternalStorageDocument(Uri uri) {
    return "com.android.externalstorage.documents".equals(uri.getAuthority());
}

/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is DownloadsProvider.
 */
public static boolean isDownloadsDocument(Uri uri) {
    return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}

/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is MediaProvider.
 */
public static boolean isMediaDocument(Uri uri) {
    return "com.android.providers.media.documents".equals(uri.getAuthority());
}

/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is Google Photos.
 */
public static boolean isGooglePhotosUri(Uri uri) {
    return "com.google.android.apps.photos.content".equals(uri.getAuthority());
}

使用以下代码浏览任何格式的文件。

public void browseClick() {

    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.setType("*/*");
    intent.addCategory(Intent.CATEGORY_OPENABLE);
    //intent.putExtra("browseCoa", itemToBrowse);
    //Intent chooser = Intent.createChooser(intent, "Select a File to Upload");
    try {
        //startActivityForResult(chooser, FILE_SELECT_CODE);
        startActivityForResult(Intent.createChooser(intent, "Select a File to Upload"),FILE_SELECT_CODE);
    } catch (Exception ex) {
        System.out.println("browseClick :"+ex);//android.content.ActivityNotFoundException ex
    }
}

然后在 onActivityResult 中获取该文件路径，如下所示。

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == FILE_SELECT_CODE) {
        if (resultCode == RESULT_OK) {
            try {
              Uri uri = data.getData();

                if (filesize >= FILE_SIZE_LIMIT) {
                    Toast.makeText(this,"The selected file is too large. Selet a new file with size less than 2mb",Toast.LENGTH_LONG).show();
                } else {
                    String mimeType = getContentResolver().getType(uri);
                    if (mimeType == null) {
                        String path = getPath(this, uri);
                        if (path == null) {
                            filename = FilenameUtils.getName(uri.toString());
                        } else {
                            File file = new File(path);
                            filename = file.getName();
                        }
                    } else {
                        Uri returnUri = data.getData();
                        Cursor returnCursor = getContentResolver().query(returnUri, null, null, null, null);
                        int nameIndex = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
                        int sizeIndex = returnCursor.getColumnIndex(OpenableColumns.SIZE);
                        returnCursor.moveToFirst();
                        filename = returnCursor.getString(nameIndex);
                        String size = Long.toString(returnCursor.getLong(sizeIndex));
                    }
   File fileSave = getExternalFilesDir(null);
    String sourcePath = getExternalFilesDir(null).toString();
    try {
                        copyFileStream(new File(sourcePath + "/" + filename), uri,this);

                    } catch (Exception e) {
                        e.printStackTrace();
                    }
  }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}
private void copyFileStream(File dest, Uri uri, Context context)
        throws IOException {
    InputStream is = null;
    OutputStream os = null;
    try {
        is = context.getContentResolver().openInputStream(uri);
        os = new FileOutputStream(dest);
        byte[] buffer = new byte[1024];
        int length;

        while ((length = is.read(buffer)) > 0) {
            os.write(buffer, 0, length);

        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        is.close();
        os.close();
    }
}

在此之后，您可以通过适当的操作从保存文件的应用程序外部存储中打开此文件。

Answer 2

我刚刚遇到了一个错误

final String docId = DocumentsContract.getDocumentId(uri);

return 不同的 URI（例如：content://com.android.providers.downloads.documents/document/11 有时 content://com.android.providers.downloads.documents/document/abc%aile.jpg 在这种情况下 Long.valueOf(id) 抛出异常来修复

String id = DocumentsContract.getDocumentId(uri);
                if (id.startsWith("raw:")) {
                    id = id.replaceFirst("raw:", "");
                    return id;
                }
                final Uri contentUri = ContentUris.withAppendedId(
                    Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

                return getDataColumn(contentUri, null, null);

这样做 return ID，对我有用

Answer 3

关于 kotlin 的公认答案

@Suppress("SpellCheckingInspection")
object PathCompat {

    @WorkerThread
    fun getFilePath(context: Context, uri: Uri): String? = context.run {
        return try {
            when {
                Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT -> getDataColumn(uri, null, null)
                else -> getPathKitkatPlus(uri)
            }
        } catch (e: Throwable) {
            Timber.e(e)
            null
        }
    }

    @Suppress("DEPRECATION")
    @SuppressLint("NewApi", "DefaultLocale")
    private fun Context.getPathKitkatPlus(uri: Uri): String? {
        when {
            DocumentsContract.isDocumentUri(applicationContext, uri) -> {
                val docId = DocumentsContract.getDocumentId(uri)
                when {
                    uri.isExternalStorageDocument -> {
                        val parts = docId.split(":")
                        if ("primary".equals(parts[0], true)) {
                            return "${Environment.getExternalStorageDirectory()}/${parts[1]}"
                        }
                    }
                    uri.isDownloadsDocument -> {
                        val contentUri = ContentUris.withAppendedId(
                            Uri.parse("content://downloads/public_downloads"),
                            docId.toLong()
                        )
                        return getDataColumn(contentUri, null, null)
                    }
                    uri.isMediaDocument -> {
                        val parts = docId.split(":")
                        val contentUri = when (parts[0].toLowerCase()) {
                            "image" -> MediaStore.Images.Media.EXTERNAL_CONTENT_URI
                            "video" -> MediaStore.Video.Media.EXTERNAL_CONTENT_URI
                            "audio" -> MediaStore.Audio.Media.EXTERNAL_CONTENT_URI
                            else -> return null
                        }
                        return getDataColumn(contentUri, "_id=?", arrayOf(parts[1]))
                    }
                }
            }
            "content".equals(uri.scheme, true) -> {
                return if (uri.isGooglePhotosUri) {
                    uri.lastPathSegment
                } else {
                    getDataColumn(uri, null, null)
                }
            }
            "file".equals(uri.scheme, true) -> {
                return uri.path
            }
        }
        return null
    }

    private fun Context.getDataColumn(uri: Uri, selection: String?, args: Array<String>?): String? {
        contentResolver?.query(uri, arrayOf("_data"), selection, args, null)?.use {
            if (it.moveToFirst()) {
                return it.getString(it.getColumnIndexOrThrow("_data"))
            }
        }
        return null
    }

    private val Uri.isExternalStorageDocument: Boolean
        get() = authority == "com.android.externalstorage.documents"

    private val Uri.isDownloadsDocument: Boolean
        get() = authority == "com.android.providers.downloads.documents"

    private val Uri.isMediaDocument: Boolean
        get() = authority == "com.android.providers.media.documents"

    private val Uri.isGooglePhotosUri: Boolean
        get() = authority == "com.google.android.apps.photos.content"
}

Answer 4

使用系统文件选择器选择任意文件：

val intent = Intent(Intent.ACTION_GET_CONTENT)
intent.type = "*/*"
startActivityForResult(intent, 1)

onActivityResult:

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    if (requestCode == 1 && resultCode == Activity.RESULT_OK) {
        data?.data?.let {
            getFileFromUri(requireContext().contentResolver, uri, requireContext().cacheDir)
        }
    }
}

获取文件：

private fun getFileFromUri(contentResolver: ContentResolver, uri: Uri, directory: File): File {
    val file =
        File.createTempFile("suffix", "prefix", directory)
    file.outputStream().use {
        contentResolver.openInputStream(uri)?.copyTo(it)
    }

    return file
}

Android 打开文件 ACTION_GET_CONTENT 导致不同的 URI

Android opening a file with ACTION_GET_CONTENT results into different Uri's

android

file-browser

2017 年 2 月 6 日更新：