Android 7.0以上把content://形式uri路径转为string绝对路径的两个方法

 版本7.0以上打开图库，获取图片的路径都是content://com...形式的uri，以下两个方法配合使用可以将uri转为string的绝对路径

 

    /**
     * 专为Android4.4设计的从Uri获取文件绝对路径，以前的方法已不好使
     */
    @SuppressLint("NewApi")
    public String getPath(final Context context, final 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];
                }
            }
            // 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 getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }
        return null;
    }

 /**
     * Get the value of the data column for this Uri. This is useful for
     * MediaStore Uris, and other file-based ContentProviders.editTextCardID
     *
     * @param context       The context.
     * @param uri           The Uri to query.
     * @param selection     (Optional) Filter used in the query.
     * @param selectionArgs (Optional) Selection arguments used in the query.
     * @return The value of the _data column, which is typically a file path.
     */
    public 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;
    }

  版本7.0以上打开文件管理，获取图片的路径都是content://com...形式的uri，以下两个方法配合使用可以将uri转为string的绝对路径

  public static String getFilePathByUri(Context context, Uri uri) {
        String path = null;
        List packs = context.getPackageManager().getInstalledPackages(PackageManager.GET_PROVIDERS);
        if (packs != null) {
            String fileProviderClassName = FileProvider.class.getName();
            for (PackageInfo pack : packs) {
                ProviderInfo[] providers = pack.providers;
                if (providers != null) {
                    for (ProviderInfo provider : providers) {
                        if (uri.getAuthority().equals(provider.authority)) {
                            if (provider.name.equalsIgnoreCase(fileProviderClassName)) {
                                Class fileProviderClass = FileProvider.class;
                                try {
                                    Method getPathStrategy = fileProviderClass.getDeclaredMethod("getPathStrategy", Context.class, String.class);
                                    getPathStrategy.setAccessible(true);
                                    Object invoke = getPathStrategy.invoke(null, context, uri.getAuthority());
                                    if (invoke != null) {
                                        String PathStrategyStringClass = FileProvider.class.getName() + "$PathStrategy";
                                        Class PathStrategy = Class.forName(PathStrategyStringClass);
                                        Method getFileForUri = PathStrategy.getDeclaredMethod("getFileForUri", Uri.class);
                                        getFileForUri.setAccessible(true);
                                        Object invoke1 = getFileForUri.invoke(invoke, uri);
                                        if (invoke1 instanceof File) {
                                            path = ((File) invoke1).getAbsolutePath();
                                        }
                                    }
                                } catch (NoSuchMethodException e) {
                                    e.printStackTrace();
                                } catch (InvocationTargetException e) {
                                    e.printStackTrace();
                                } catch (IllegalAccessException e) {
                                    e.printStackTrace();
                                } catch (ClassNotFoundException e) {
                                    e.printStackTrace();
                                }

                                break;
                            }
                            break;
                        }
                    }

                }

            }
        }
        return path;
    }