Parsing Daten von json

Question

JSON-Daten

{ 
    "kind": "books#volumes", 
    "totalItems": 111, 
    "items": [{ 
     "kind": "books#volume", 
     "id": "wmMmkAFHlfAC", 
     "etag": "m5G7DGubjpc", 
     "selfLink": "https://www.googleapis.com/books/v1/volumes/wmMmkAFHlfAC", 
     "volumeInfo": { 
      "title": "They!", 
      "authors": ["Chuck Keyes"], 
      "publisher": "Larry Larson", 
      "publishedDate": "2011-09-08", 
      "industryIdentifiers": [{ 
       "type": "ISBN_13", 
       "identifier": "9781465704771" 
      }, 
      { 
       "type": "ISBN_10", 
       "identifier": "1465704779" 
      }], 
      "readingModes": { 
       "text": true, 
       "image": true 
      }, 
      "printType": "BOOK", 
      "categories": ["Fiction"], 
      "maturityRating": "NOT_MATURE", 
      "allowAnonLogging": false, 
      "contentVersion": "0.2.1.0.preview.3", 
      "panelizationSummary": { 
       "containsEpubBubbles": false, 
       "containsImageBubbles": false 
      }, 
      "imageLinks": { 
       "smallThumbnail": "http://books.google.com/books/content?id=wmMmkAFHlfAC&printsec=frontcover&img=1&zoom=5&edge=curl&source=gbs_api", 
       "thumbnail": "http://books.google.com/books/content?id=wmMmkAFHlfAC&printsec=frontcover&img=1&zoom=1&edge=curl&source=gbs_api" 
      }, 
      "language": "en", 
      "previewLink": "http://books.google.co.in/books?id=wmMmkAFHlfAC&pg=PT220&dq=roses+inauthor:keyes&hl=&cd=1&source=gbs_api", 
      "infoLink": "http://books.google.co.in/books?id=wmMmkAFHlfAC&dq=roses+inauthor:keyes&hl=&source=gbs_api", 
      "canonicalVolumeLink": "https://books.google.com/books/about/They.html?hl=&id=wmMmkAFHlfAC" 
     }, 
     "saleInfo": { 
      "country": "IN", 
      "saleability": "NOT_FOR_SALE", 
      "isEbook": false 
     }, 
     "accessInfo": { 
      "country": "IN", 
      "viewability": "PARTIAL", 
      "embeddable": true, 
      "publicDomain": false, 
      "textToSpeechPermission": "ALLOWED", 
      "epub": { 
       "isAvailable": true, 
       "acsTokenLink": "http://books.google.co.in/books/download/They-sample-epub.acsm?id=wmMmkAFHlfAC&format=epub&output=acs4_fulfillment_token&dl_type=sample&source=gbs_api" 
      }, 
      "pdf": { 
       "isAvailable": true, 
       "acsTokenLink": "http://books.google.co.in/books/download/They-sample-pdf.acsm?id=wmMmkAFHlfAC&format=pdf&output=acs4_fulfillment_token&dl_type=sample&source=gbs_api" 
      }, 
      "webReaderLink": "http://play.google.com/books/reader?id=wmMmkAFHlfAC&hl=&printsec=frontcover&output=reader&source=gbs_api", 
      "accessViewStatus": "SAMPLE", 
      "quoteSharingAllowed": false 
     }, 
     "searchInfo": { 
      "textSnippet": "She quickly returned with the bouquet of mixed colored \u003cb\u003eroses\u003c/b\u003e surrounded with \u003cbr\u003e\nbaby's breath. "These are mine! My husband has never given me such a beautiful \u003cbr\u003e\nbouquet of \u003cb\u003eroses\u003c/b\u003e." "Armed home invaders possessed by a deranged queen ..." 
     } 
    }] 
} 

Meine Codedaten zu holen

private static List<Word> extractFeatureFromJson(String earthquakeJSON) { 
     // If the JSON string is empty or null, then return early. 
     if (TextUtils.isEmpty(earthquakeJSON)) { 
      return null; 
     } 

     // Create an empty ArrayList that we can start adding earthquakes to 

     List<Word> earthquakes = new ArrayList<>(); 


     // Try to parse the JSON response string. If there's a problem with the way the JSON 
     // is formatted, a JSONException exception object will be thrown. 
     // Catch the exception so the app doesn't crash, and print the error message to the logs. 
     try { 


      // Create a JSONObject from the JSON response string 
      JSONObject baseJsonResponse = new JSONObject(earthquakeJSON); 
      // Extract the JSONArray associated with the key called "features", 
      // which represents a list of features (or earthquakes). 
      JSONArray earthquakeArray = baseJsonResponse.getJSONArray("items"); 
      // For each earthquake in the earthquakeArray, create an {@link EarthquakeAdapter} object 
      for (int i = 0; i < earthquakeArray.length(); i++) { 

       // Get a single earthquake at position i within the list of earthquakes 
       JSONObject currentEarthquake = earthquakeArray.getJSONObject(i); 

       // For a given earthquake, extract the JSONObject associated with the 
       // key called "properties", which represents a list of all properties 
       // for that earthquake. 
       JSONObject properties = currentEarthquake.getJSONObject("volumeInfo"); 

       // Extract the value for the key called "mag" 

       String location = currentEarthquake.getString("title"); 

       double magnitude = currentEarthquake.getDouble("publishedDate"); 
       // Extract the value for the key called "time" 
       long time = currentEarthquake.getLong("pageCount"); 

       // Extract the value for the key called "url" 
       String url = currentEarthquake.getString("description"); 

       // Create a new {@link EarthquakeAdapter} object with the magnitude, location, time, 
       // and url from the JSON response. 
       Word earthquake = new Word(magnitude, location, time, url); 

       // Add the new {@link EarthquakeAdapter} to the list of earthquakes. 
       earthquakes.add(earthquake); 
      } 

     } catch (JSONException e) { 
      // If an error is thrown when executing any of the above statements in the "try" block, 
      // catch the exception here, so the app doesn't crash. Print a log message 
      // with the message from the exception. 
      Log.e("QueryUtils", "Problem parsing the earthquake JSON results", e); 
     } 
     // Return the list of earthquakes 
     return earthquakes; 
    } 

Ich habe diese Json Daten genommen und versucht, aus dem obigen Code zu holen, aber es funktioniert nicht. Fehler, die angezeigt wird, ist

„Problem Parsen der Erdbeben JSON Ergebnisse org.json.JSONException: Kein Wert für den Titel“

Answer 1

Soweit ich sehen kann, der Fehler in der Wurzelobjekt liegt, wo Sie versuchen, um die title aus zu holen.

  // For a given earthquake, extract the JSONObject associated with the 
      // key called "properties", which represents a list of all properties 
      // for that earthquake. 
      JSONObject properties = currentEarthquake.getJSONObject("volumeInfo"); 

      // Extract the value for the key called "mag" 

      String location = currentEarthquake.getString("title"); 

title ist kein Kind von currentEarthquake aber von volumeInfo.

  String location = properties.getString("title"); 

sollte korrekt sein.

Answer 2

"Problem, das Erdbeben JSON Parsen Ergebnisse org.json.JSONException: Kein Wert für title".

Verwenden properties.getString("title") statt currentEarthquake.getString("title") und bekommen description, pageCount, publishedDate und thumbnail meine unten Codes versuchen.

Try this:

try { 

     JSONObject baseJsonResponse = new JSONObject(earthquakeJSON); 
     JSONArray earthquakeArray = baseJsonResponse.getJSONArray("items"); 
     for (int i = 0; i < earthquakeArray.length(); i++) { 

      JSONObject currentEarthquake = earthquakeArray.getJSONObject(i); 

      JSONObject volumeInfo = currentEarthquake.getJSONObject("volumeInfo"); 
      String title = volumeInfo.getString("title"); 

      String publishedDate = volumeInfo.getString("publishedDate"); 
      String description = volumeInfo.getString("description"); 
      int pageCount = volumeInfo.getInt("pageCount"); 

      JSONObject imageLinks = volumeInfo.getJSONObject("imageLinks"); 
      String thumbnail = imageLinks.getString("thumbnail"); 

      .................... 
      .......................... 
     } 

    } catch (JSONException e) { 
     // If an error is thrown when executing any of the above statements in the "try" block, 
     // catch the exception here, so the app doesn't crash. Print a log message 
     // with the message from the exception. 
     Log.e("QueryUtils", "Problem parsing the earthquake JSON results", e); 
    } 

FYI, Es gibt keine averageRating Schlüssel in Ihrem json.