Android7.0以上Uri转路径的方法（已验证）

网络上看到过很多种Uri转路径的方法，可基本上都只适用于很少的Uri值，可能没有结果(例如，对于由MediaStore索引的非本地文件)，也可能没有可用的结果(例如，对于可移动存储上的文件)。

解决方法

使用ContentResolver和openInputStream()在Uri标识的内容上获取InputStream。在控制的文件上使用InputStream和FileOutputStream复制内容，然后使用该文件。

代码如下：

private static String getFilePathForN(Context context, Uri uri) {
    try {
        Cursor returnCursor = context.getContentResolver().query(uri, null, null, null, null);
        int nameIndex = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
        returnCursor.moveToFirst();
        String name = (returnCursor.getString(nameIndex));
        File file = new File(context.getFilesDir(), name);
        InputStream inputStream = context.getContentResolver().openInputStream(uri);
        FileOutputStream outputStream = new FileOutputStream(file);
        int read = 0;
        int maxBufferSize = 1 * 1024 * 1024;
        int bytesAvailable = inputStream.available();
        int bufferSize = Math.min(bytesAvailable, maxBufferSize);
        final byte[] buffers = new byte[bufferSize];
        while ((read = inputStream.read(buffers)) != -1) {
            outputStream.write(buffers, 0, read);
        }
        returnCursor.close();
        inputStream.close();
        outputStream.close();
        return file.getPath();
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

附上全系统的代码：

/**
 * 文件Uri转路径（兼容各品牌手机）
 */
public class PathUtils {
    /**
     * android7.0以上处理方法
     */
    private static String getFilePathForN(Context context, Uri uri) {
        try {
            Cursor returnCursor = context.getContentResolver().query(uri, null, null, null, null);
            int nameIndex = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
            returnCursor.moveToFirst();
            String name = (returnCursor.getString(nameIndex));
            File file = new File(context.getFilesDir(), name);
            InputStream inputStream = context.getContentResolver().openInputStream(uri);
            FileOutputStream outputStream = new FileOutputStream(file);
            int read = 0;
            int maxBufferSize = 1 * 1024 * 1024;
            int bytesAvailable = inputStream.available();

            int bufferSize = Math.min(bytesAvailable, maxBufferSize);

            final byte[] buffers = new byte[bufferSize];
            while ((read = inputStream.read(buffers)) != -1) {
                outputStream.write(buffers, 0, read);
            }
            returnCursor.close();
            inputStream.close();
            outputStream.close();
            return file.getPath();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 全平台处理方法
     */
    public static String getPath(final Context context, final Uri uri) throws Exception {

        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
        final boolean isN = Build.VERSION.SDK_INT >= Build.VERSION_CODES.N;

        if (isN) {
            return getFilePathForN(context, uri);
        }

        // 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"), StringUtils.toLong(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;
    }

    /**
     * 获取此Uri的数据列的值。这对于MediaStore uri和其他基于文件的内容提供程序非常有用。
     */
    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 column_index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(column_index);
            }
        } catch (IllegalArgumentException e){
            //do nothing
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }

    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());
    }
}

参考资料：https://stackoverflow.com/questions/42508383/illegalargumentexception-column-data-does-not-exist