如何從JSONObject中檢索Id

Question

我無法從JSONObject中檢索Id並將其傳遞給字符串以記錄該玩家的特定拼圖的Id，但在行上String idString = obj.getString（「 ID」）;

「我得到org.json.JSONException：Id的無值」

我通過調用這個類檢查玩家的用戶名和密碼的服務器獲取這些信息。

import android.os.AsyncTask; 
import android.text.format.Time; 
import android.util.Log; 

public class GetTodaysPuzzle implements OnRetrieveHttpData { 

    public String GetTodaysPuzzle(String mUserName, String mPassword) 
    { 
     RetrieveHTTPData GetTodayspuzzle = new RetrieveHTTPData(this); 
     return GetTodayspuzzle.GetResponseData("urlString" + mUserName + "&password=" + mPassword); 
    } 

    @Override 
    public void onRetrieveTaskCompleted(String httpData) { 
     Log.i("Server Response", httpData); 
    } 

    class GetTodaysPuzzleTask extends AsyncTask<String, String, Boolean> { 

     @Override 
     protected Boolean doInBackground(String... params) { 
      // Get response from server 
      String json = GetTodaysPuzzle(params[0], params[1]); 

      // Check if a puzzle was returned 
      if (json.contains("The request is invalid")) 
      { 
       return false; 
      } 

      try 
      { 
       // Calculate today's date in order to set wordsearch date 
       Time today = new Time(); 
       today.setToNow(); 
       String formattedDate = Dates.ConvertUStoUK(today.year + "-" 
         + (today.month + 1) + "-" + today.monthDay); 

       // Create wordsearch 
       WordSearch wordSearch = WordSearch.CreateWordSearch(json, 
         formattedDate); 

       if (wordSearch == null) 
       { 
        return false; 
       } 

       // Save wordsearch to collection 
       WordSearchDatabase.Add(wordSearch); 
       // WordSearchDatabase.Save(); 
       return true; 
      } 
      catch (Exception e) 
      { 
       Log.e("GetTodaysPuzzleTask", e.getMessage()); 
       return false; 
      } 
     } 
    } 

} 

然後將所有信息存儲到Wordsearch類的JSONArrays中。

import java.util.ArrayList; 
import java.util.List; 
import org.json.JSONArray; 
import org.json.JSONObject; 

public class WordSearch { 

    public String    Id; 
    public String    Date; 
    public List<Word>   Words; 
    public Letter[]    Letters; 
    public final int   NUM_OF_ROWS; 
    public final int   NUM_OF_COLS; 
    public int     Score    = -1; 

    private boolean    containsSolution = false; 
    public boolean    canBeSubmitted  = true; 
    private boolean    complete   = false; 
    private boolean    submitted   = false; 


    public static WordSearch CreateWordSearch(String json, String date) 
    { 
     List<Word> listOfWords = new ArrayList<Word>(); 
     List<String> listOfRows = new ArrayList<String>(); 

     try 
     { 
      // Create a JSON Object from JSON string 
      JSONObject obj = new JSONObject(json); 

      // Get Id 
      String idString = obj.getString("Id"); 

      // GetWords & Puzzle as JSON Arrays 
      JSONArray wordsArray = obj.getJSONArray("Words"); 
      JSONArray puzzleArray = obj.getJSONArray("Grid"); 

      // Parse Words array 
      for (int i = 0; i < wordsArray.length(); i++) 
      { 
       String name = wordsArray.getString(i); 
       Word word = new Word(name); 
       listOfWords.add(word); 
      } 

      // Parse Puzzle 
      for (int k = 0; k < puzzleArray.length(); k++) 
      { 
       String puzzle = puzzleArray.getString(k); 
       listOfRows.add(puzzle); 
      } 

      // Create WordSearch 
      return new WordSearch(idString, date, listOfWords, listOfRows, 
        false); 
     } 
     catch (Exception e) 
     { 
      e.printStackTrace(); 
      return null; 
     } 
    } 
} 

這是我第一次在Android中使用API​​服務器和JSONObject的，所以任何幫助將不勝感激。謝謝。

Answer 1

您收到此錯誤，因爲你的反應JSON沒有「身份證」作爲重點，它不僅具有「益智」，你可以看到：

{ 
    "Puzzle": { 
     "Id": "8fb25209-863a-410b-a440-b5b57a903ee1", 
     "Words": ["CHATEAUX", ...], 
     "Grid": ["TLIOFSHTRC", ...] 
    } 
} 

您需要先獲得「拼圖「首先對象，然後你可以從該對象中獲得」Id「。

JSONObject obj = new JSONObject(json); 
JSONObject puzzle = obj.getJSONObject("Puzzle"); 
String idString = puzzle.getString("Id"); 
.... 

Answer 2

標識是在益智元素，所以應該是

JSONObject obj = new JSONObject(json); 

//get puzzle object 
JSONObject puzzle = obj.getJSONObject("Puzzle"); 
// Get Id 
String idString = puzzle.getString("Id"); 

// GetWords & Puzzle as JSON Arrays 
JSONArray wordsArray = puzzle.getJSONArray("Words"); 
JSONArray puzzleArray = puzzle.getJSONArray("Grid");