public String getPath(Uri uri) {
    Cursor cursor = getContentResolver().query(uri, null, null, null, null);
    cursor.moveToFirst();
    String document_id = cursor.getString(0);
    document_id = document_id.substring(document_id.lastIndexOf(":") + 1);
    cursor.close();

    cursor = getContentResolver().query(
            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
            null, MediaStore.Images.Media._ID + " = ? ", new String[]{document_id}, null);
    cursor.moveToFirst();
    String path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
    cursor.close();

    return path;
}

将文件URI转换为字符串filePath的完美工作方法

不要尝试在文件系统中查找uri，那样在数据库中查找东西会很慢。

你可以通过给工厂一个输入流来从uri中获得位图，就像给工厂一个文件一样:

InputStream is = getContentResolver().openInputStream(uri);
Bitmap bitmap = BitmapFactory.decodeStream(is);
is.close();

下面API 19使用这段代码从URI中获取文件路径:

public String getRealPathFromURI(Context context, Uri contentUri) {
  Cursor cursor = null;
  try { 
    String[] proj = { MediaStore.Images.Media.DATA };
    cursor = context.getContentResolver().query(contentUri,  proj, null, null, null);
    int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
    cursor.moveToFirst();
    return cursor.getString(column_index);
  } finally {
    if (cursor != null) {
      cursor.close();
    }
  }
}

如果你的系统版本在19以上，这对我来说是完美的，希望这能帮助你。

  @TargetApi(Build.VERSION_CODES.KITKAT)
    public static String getPath(final Context context, final Uri uri) {
        final boolean isOverKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
        // DocumentProvider
        if (isOverKitKat && 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 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;
    }

像下面这样获取Uri。

//* get cursor like normal

Then

while (cursor.moveToNext()) {
    Uri uri = ContentUris.withAppendedId(
    MediaStore.Images.Media.EXTERNAL_CONTENT_URI, id);
}

从图库中获取图像后，只需要在下面的方法中传递URI，仅适用于Android 4.4 (KitKat):

public String getPath(Uri contentUri) {// Will return "image:x*"

    String wholeID = DocumentsContract.getDocumentId(contentUri);

    // Split at colon, use second item in the array
    String id = wholeID.split(":")[1];

    String[] column = { MediaStore.Images.Media.DATA };

    // Where id is equal to
    String sel = MediaStore.Images.Media._ID + "=?";

    Cursor cursor = getContentResolver().query(
            MediaStore.Images.Media.EXTERNAL_CONTENT_URI, column, sel,
            new String[] { id }, null);

    String filePath = "";

    int columnIndex = cursor.getColumnIndex(column[0]);

    if (cursor.moveToFirst()) {
        filePath = cursor.getString(columnIndex);
    }

    cursor.close();
    return filePath;
}