通过URI返回File文件

    /**
      * 通过Uri返回File文件
      * 注意：通过相机的是类似content://media/external/images/media/97596
      * 通过相册选择的：file:///storage/sdcard0/DCIM/Camera/IMG_20150423_161955.jpg
      * 通过查询获取实际的地址
      * @param uri
      * @return
      */
     public File getFileByUri(Uri uri) {
         String path = null;
         if ("file".equals(uri.getScheme())) {
             path = uri.getEncodedPath();
             if (path != null) {
                 path = Uri.decode(path);
                 ContentResolver cr = activity.getContentResolver();
                 StringBuffer buff = new StringBuffer();
                 buff.append("(").append(Images.ImageColumns.DATA).append("=").append("'" + path + "'").append(")");
                 Cursor cur = cr.query(Images.Media.EXTERNAL_CONTENT_URI, new String[] { Images.ImageColumns._ID, Images.ImageColumns.DATA }, buff.toString(), null, null);
                 int index = ;
                 int dataIdx = ;
                 for (cur.moveToFirst(); !cur.isAfterLast(); cur.moveToNext()) {
                     index = cur.getColumnIndex(Images.ImageColumns._ID);
                     index = cur.getInt(index);
                     dataIdx = cur.getColumnIndex(Images.ImageColumns.DATA);
                     path = cur.getString(dataIdx);
                 }
                 cur.close();
                 if (index == ) {
                 } else {
                     Uri u = Uri.parse("content://media/external/images/media/" + index);
                     System.out.println("temp uri is :" + u);
                 }
             }
             if (path != null) {
                 return new File(path);
             }
         } else if ("content".equals(uri.getScheme())) {
             // 4.2.2以后
             String[] proj = { MediaStore.Images.Media.DATA };
             Cursor cursor = activity.getContentResolver().query(uri, proj, null, null, null);
             if (cursor.moveToFirst()) {
                 int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                 path = cursor.getString(columnIndex);
             }
             cursor.close();  

             return new File(path);
         } else {
             Log.i(TAG, "Uri Scheme:" + uri.getScheme());
         }
         return null;
     }