java.lang.String中不能JsonArray

Question

轉換，我不知道爲什麼，但是當我嘗試從JSON獲取數據我得到這個錯誤：

java.lang.String中不能Jsonarray

轉換

這是我的代碼，

主要活動：

public class MainActivity extends AppCompatActivity { 

    // CONNECTION_TIMEOUT and READ_TIMEOUT are in milliseconds 
    public static final int CONNECTION_TIMEOUT = 10000; 
    public static final int READ_TIMEOUT = 15000; 
    private RecyclerView mRVFishPrice; 
    private AdapterProgram mAdapter; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     //Make call to AsyncTask 
     new AsyncFetch().execute(); 
    } 

    private class AsyncFetch extends AsyncTask<String, String, String> { 
     ProgressDialog pdLoading = new ProgressDialog(MainActivity.this); 
     HttpURLConnection conn; 
     URL url = null; 

     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 

      //this method will be running on UI thread 
      pdLoading.setMessage("\tLoading..."); 
      pdLoading.setCancelable(false); 
      pdLoading.show(); 

     } 

     @Override 
     protected String doInBackground(String... params) { 
      try { 

       // Enter URL address where your json file resides 
       // Even you can make call to php file which returns json data 
       url = new URL("http://v1.tvguideapi.com/programs?channels[]=2161&channels[]=2162&channels[]=2163&start=1484685000&stop=1484690400"); 

      } catch (MalformedURLException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
       return e.toString(); 
      } 
      try { 

       // Setup HttpURLConnection class to send and receive data from php and mysql 
       conn = (HttpURLConnection) url.openConnection(); 
       conn.setReadTimeout(READ_TIMEOUT); 
       conn.setConnectTimeout(CONNECTION_TIMEOUT); 
       conn.addRequestProperty("Authorization", "nSLkk3o6xowTgXryFVxWaVSRW3zxNwlzmYIcgCkE"); 
       conn.setRequestMethod("GET"); 

       // setDoOutput to true as we recieve data from json file 
       conn.setDoOutput(true); 

      } catch (IOException e1) { 
       // TODO Auto-generated catch block 
       e1.printStackTrace(); 
       return e1.toString(); 
      } 

      try { 

       int response_code = conn.getResponseCode(); 

       // Check if successful connection made 
       if (response_code == HttpURLConnection.HTTP_OK) { 

        // Read data sent from server 
        InputStream input = conn.getInputStream(); 
        BufferedReader reader = new BufferedReader(new InputStreamReader(input)); 
        StringBuilder result = new StringBuilder(); 
        String line; 

        while ((line = reader.readLine()) != null) { 
         result.append(line); 
        } 

        // Pass data to onPostExecute method 
        return (result.toString()); 

       } else { 

        return ("unsuccessful"); 
       } 

      } catch (IOException e) { 
       e.printStackTrace(); 
       return e.toString(); 
      } finally { 
       conn.disconnect(); 
      } 


     } 

     @Override 
     protected void onPostExecute(String result) { 

      //this method will be running on UI thread 

      pdLoading.dismiss(); 
      List<Programs> data=new ArrayList<>(); 

      pdLoading.dismiss(); 
      try { 

       JSONArray jArray = new JSONArray(result); 

       // Extract data from json and store into ArrayList as class objects 
       for(int i=0;i<jArray.length();i++){ 
        JSONObject json_data = jArray.getJSONObject(i); 
        Programs fishData = new Programs(); 
        fishData.title= json_data.getString("title"); 
        fishData.description= json_data.getString("description"); 
        // fishData.catName= json_data.getString("cat_name"); 
        // fishData.sizeName= json_data.getString("size_name"); 
        // fishData.price= json_data.getInt("price"); 
        data.add(fishData); 
       } 

       // Setup and Handover data to recyclerview 
       mRVFishPrice = (RecyclerView)findViewById(R.id.fishPriceList); 
       mAdapter = new AdapterProgram(MainActivity.this, data); 
       mRVFishPrice.setAdapter(mAdapter); 
       mRVFishPrice.setLayoutManager(new LinearLayoutManager(MainActivity.this)); 

      } catch (JSONException e) { 
       Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show(); 
      } 

     } 

    } 
} 

JSON：

[ 
    { 
    "id": "18631557", 
    "start": "2017-01-17 21:03:00", 
    "stop": "2017-01-17 22:55:00", 
    "lang": "", 
    "title": "The Town", 
    "subtitle": "", 
    "description": "Regia: Ben Affleck - Cast: Jeremy Renner, Blake Lively, Ben Affleck, Jon Hamm. POLIZIESCO 120' - Stati Uniti D'America, 2010.", 
    "category": "", 
    "channel_id": "2142", 
    "icon": null, 
    "ts_start": 1484686980, 
    "ts_stop": 1484693700 
    } 
] 

Answer 1

我相信（response_code不是200），你的問題是關係到你的查詢失敗的事實，所以doInBackground回報"unsuccessful"這顯然不是JSON對象的數組，所以你最終與此例外。您應該返回空數組"[]"而不是"unsuccessful"。因爲你的頭Authorization未正確設置它應該與「Basic」後面${username}:${password}使用RFC2045-MIME變種Base64編碼開始

你的要求可能會失敗。有關基本認證的更多細節here。