Android:所有文件都不可读。文件查找器

Question

我正在尝试让查找器获取“.pdf”，我得到了我的 Uri，文件存在，但他总是为 File.canRead() 返回 false

就在尝试将该文档上传到我的解析服务器之前，我记录了这个:

final File file = new File(path);
Log.d("=== TAG ====", file.getAbsolutePath());
Log.d("=== TAG ====", String.valueOf(file.exists()));
Log.d("=== TAG ====", String.valueOf(file.canRead()));

给我这个:

06-27 10:58:03.746 24136-24136/bruce.team D/=== TAG ====: /storage/emulated/0/Download/random.pdf
06-27 10:58:03.747 24136-24136/bruce.team D/=== TAG ====: true
06-27 10:58:03.747 24136-24136/bruce.team D/=== TAG ====: false

15秒后上传失败，我的解析服务器无法访问所以一定是读取问题!

list :

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

我的选择方式:

public static void pick(final Controller controller) {
    final Intent chooseFileIntent = new Intent(Intent.ACTION_GET_CONTENT);
    chooseFileIntent.setType("application/pdf");
    chooseFileIntent.addCategory(Intent.CATEGORY_OPENABLE);
    if (chooseFileIntent.resolveActivity(controller.getContext().getPackageManager()) != null) {
        controller.startActivityForResult(chooseFileIntent, Configuration.Request.Code.Pdf.Pdf);
    }
}

所以我的问题是为什么 canRead 总是返回 false ？如何阅读？

编辑:我获得路径的方式对我来说似乎很好。

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

    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }

    public static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri.getAuthority());
    }

    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 String getPath(Context context, Uri uri) {
        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

        // DocumentProvider
        if (isKitKat && 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;
    }

我的 Activity 结果:

@Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == Configuration.Request.Code.Pdf.Pdf) {
            if (resultCode == RESULT_OK) {
                Uri fileUri = data.getData();
                if (Session.User != null) {
                    final Document document = new Document(Session.User);
                    document.setCategory(Document.Category.CurriculumVitae);
                    document.setType("PDF");
                    document.save(getContext(), fileUri, new Uploader.Handler() {
                        @Override
                        public void progress(Integer percentage) {
                            Log.d("=====", String.valueOf(percentage));
                            if (isLoading()) {
                                int progressValue = 0;
                                progressValue += document.uploaded;
                                documentProgressBar.setProgress(60 * progressValue);
                            }
                        }
                        @Override
                        public void success() {
                            continueHeadline.setVisibility(android.view.View.VISIBLE);
                            continueButton.setVisibility(android.view.View.VISIBLE);
                        }
                        @Override
                        public void error(Error.Code code) {}
                    });
                }
            }
        }
    }

Answer 1

也许您没有读取该文件的权限。该文件可以在不允许您在其他应用程序中读取的权限下存储。