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 = 0;  
                int dataIdx = 0;  
                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 == 0) {  
                } 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;  
    }