如何在Android中通过解析顺序运行代码？

Question

我正在尝试从解析中获取记录。我的解析表包含一个指针数组；我在编写解析查询时遇到了困难，所以我首先将指针数组保存在ArrayList 中，现在我创建了一个 for 循环来执行查询；对于每个循环迭代，我想从解析和更新本地数据库中获取记录，然后与下一次迭代相同。但这会产生一些不同的问题。 parse getInBackground 没有按顺序工作....我的外部 for 循环完全执行然后调用 parse 方法，因此我在本地数据库中保存值时遇到问题。

public void insertGroupsInDB(ArrayList<TempGroupClass> temp) 
{
    Log.d(TAG,"insertGroupsInDB: temp size:"+temp.size());
    for(int i = 0;i<temp.size();i++) `//my target is to make inner query run till no of loop times and for each iterations inner parse query will run and then insert records in db against outer insertion group` 
    {
        Groups grp = new Groups();
        grp.setGroupTitle(temp.get(i).getGroupTitle());
        grp.setGroupType(temp.get(i).getGroupType());
        grp.setParseObjectId(temp.get(i).getParseObjectId());
        long groupinsert  = (YouinDatabase.getInstance(context)).addGroup(grp,context);
        //}
        /*try
          {
          final CountDownLatch latch = new CountDownLatch(1);*/
        if(groupinsert != -1)
        {
            //now insert friends
            //long friendInsertId = YouinDatabase.getInstance(context).addFriend();
            //now get friends from members id 

            Log.d(TAG,"groups inserted successfully:"+groupinsert);
            final ArrayList<Integer> list = new ArrayList<Integer>();

            if(temp.get(i).getFriendObjectIdList().size() > 0)
            {        
                for(int j =0;j<temp.get(i).getFriendObjectIdList().size();j++)
                {
                    Log.d(TAG," >>>>>>>>>>>>>>>friend objectId>>>>>>>>>>>>>>:"+temp.get(i).getFriendObjectIdList().get(j));

                    ParseQuery<ParseUser> query = ParseUser.getQuery();
                    query.whereContainedIn("objectId",temp.get(i).getFriendObjectIdList());
                    query.findInBackground(new FindCallback<ParseUser>() {

                            @Override
                            public void done(List<ParseUser> arg0,
                                    ParseException arg1) {
                            // TODO Auto-generated method stub
                            if(arg1 == null)
                            {
                            //Log.d(TAG,"arg0 size:"+arg0.size());
                            if(arg0.size() >0)
                            {
                            for(int i = 0;i<arg0.size();i++)
                            {
                            Log.d(TAG,"arg0.size():"+arg0.size());
                            Friend f = new Friend();
                            f.setUsername(arg0.get(0).getString("username"));
                            f.setParseObjectId(arg0.get(0).getObjectId());
                            f.setHasAdded(false);
                            boolean userAlreadyExist = YouinDatabase.getInstance(context).checkUserExistInFriendTable(arg0.get(0).getString("username"));
                            long friendInsertId = -1;
                            ArrayList<Integer> list = new ArrayList<Integer>();
                            int friendid;

                            if(!userAlreadyExist)
                            {
                                // Log.d(TAG,"friend Already not exist :"+userAlreadyExist);
                                friendInsertId = YouinDatabase.getInstance(context).addFriend(f);

                                list.add(YouinDatabase.getInstance(context).findFriendIdOfLatestRecord());
                                friendid = YouinDatabase.getInstance(context).findFriendIdOfLatestRecord();
                            }

                            else
                            {
                                //Log.d(TAG,"friend Already exist :"+userAlreadyExist);
                                //list.add(YouinDatabase.getInstance(context).getFriendIdFromFriendName(arg0.get(0).getString("username")));
                                friendid = YouinDatabase.getInstance(context).getFriendIdFromFriendName(arg0.get(0).getString("username"));

                            }
                            //  Log.d(TAG,"list size 1 :"+list.size());
                            int latestGroupInsertId = YouinDatabase.getInstance(context).findGroupIdOfLatestRecord();


                            long id =  YouinDatabase.getInstance(context).addFriendInConnection(friendid,latestGroupInsertId);
                            //now update user setHasAdded 
                            long updateFriendTable = -1;
                            if(id != -1)
                            {
                                updateFriendTable = YouinDatabase.getInstance(context).updateFriendTable(friendid);
                            }

                            Log.d(TAG,">>>>updated friend id information:>>>>");

                            if(updateFriendTable != -1)
                            {
                                Friend friendDetails = YouinDatabase.getInstance(context).getFriendDetailsFromFriendId(friendid);
                                Log.d(TAG,"friend name:"+friendDetails.getUsername());
                                Log.d(TAG,"friend:"+friendDetails.getParseObjectId());
                                Log.d(TAG,"friend added :"+friendDetails.isHasAdded());
                                Log.d(TAG,"groupId:"+latestGroupInsertId);
                            }
                            //YouinDatabase.getInstance(context).get
                            }
                            Log.d(TAG,"list size 2"+list.size());
                            }
                            }
                            else
                            {
                                Log.d(TAG,"arg1 != null:"+arg1.getMessage());
                            }
                            }
                    });
                }
                // Log.d(TAG,"list size:"+list.size());

            }
            //latch.countDown();
        }
        /*latch.await();
          }

          catch (IllegalArgumentException e) {
          e.printStackTrace();
          } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        }
         */
}

现在，问题是我的外部循环一个接一个地执行两次，然后在循环结束后，然后我的 parse 方法从 parse 中获取数据...由于它仅根据最后一个组 id 更新 db 中的记录。 ..它没有针对第一个 groupId 插入记录 如何解决这个问题？我使用了这种技术，因为我没有编写查询来使用 parse 获取指针数组的对象结果。

Answer 1

您可以使用find()，它应该执行可能会阻止您的用户界面的同步操作。我还没有使用解析所以我不知道。或者您可以设置如下所示的内容。删除回调中的外部条件和检查条件以确定何时启动下一个查询。

private int j = 0;
private int loopnumber = temp.size();
ArrayList<TempGroupClass> temp; //setup temp somewhere else

private void doQuery() {
    ParseQuery<ParseUser> query = ParseUser.getQuery();
    query.whereContainedIn("objectId",temp.get(i).getFriendObjectIdList());
    query.findInBackground(new FindCallback<ParseUser>() {

        @Override
        public void done(List<ParseUser> arg0,
                         ParseException arg1) {
            // TODO Auto-generated method stub
            if(arg1 == null)
            {
            ...

            ...
            else
            {
                Log.d(TAG,"arg1 != null:"+arg1.getMessage());
            }
            //at the end call the same method to start a query if the loop conditions have not been reached.
            if(++i < loopnumber) {
                doQuery();
            }
        }
    });
}
}