Android uri 转换文件路径

    public final static class Tools {
        public static String getFilePathByUri(Context context, Uri uri) {
            String path = null;
            // 以 file:// 开头的
            if (ContentResolver.SCHEME_FILE.equals(uri.getScheme())) {
                path = uri.getPath();
                return path;
            }
            // 以 content:// 开头的，比如 content://media/extenral/images/media/17766
            if (ContentResolver.SCHEME_CONTENT.equals(uri.getScheme()) && Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
                Cursor cursor = context.getContentResolver().query(uri, new String[]{MediaStore.Images.Media.DATA}, null, null, null);
                if (cursor != null) {
                    if (cursor.moveToFirst()) {
                        int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                        if (columnIndex > -1) {
                            path = cursor.getString(columnIndex);
                        }
                    }
                    cursor.close();
                }
                return path;
            }
            // 4.4及之后的 是以 content:// 开头的，比如 content://com.android.providers.media.documents/document/image%3A235700
            if (ContentResolver.SCHEME_CONTENT.equals(uri.getScheme()) && Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
                if (DocumentsContract.isDocumentUri(context, uri)) {
                    if (isExternalStorageDocument(uri)) {
                        // ExternalStorageProvider
                        final String docId = DocumentsContract.getDocumentId(uri);
                        final String[] split = docId.split(":");
                        final String type = split[0];
                        if ("primary".equalsIgnoreCase(type)) {
                            path = Environment.getExternalStorageDirectory() + "/" + split[1];
                            return path;
                        }
                    } else if (isDownloadsDocument(uri)) {
                        // DownloadsProvider
                        final String id = DocumentsContract.getDocumentId(uri);
                        final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"),
                                Long.valueOf(id));
                        path = getDataColumn(context, contentUri, null, null);
                        return path;
                    } else if (isMediaDocument(uri)) {
                        // MediaProvider
                        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]};
                        path = getDataColumn(context, contentUri, selection, selectionArgs);
                        return path;
                    }
                }
            }
            return null;
        }

        private 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 column_index = cursor.getColumnIndexOrThrow(column);
                    return cursor.getString(column_index);
                }
            } finally {
                if (cursor != null)
                    cursor.close();
            }
            return null;
        }

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

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

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

    }
    ```