JSON數據不會加載到我的Android應用程序

我需要一些操作JSON數據的建議。我已經得出了一個絕對的結論，即我用於博客的JSON數據有問題。JSON數據不會加載到我的Android應用程序

我供給JSON數據轉換成一個機器人應用程序來顯示上的應用程序的信息。我遇到的問題是，當我使用我的JSON數據時，我得到一個 negativearysize異常。

現在你怪代碼之前，知道我得到了應用程序使用teamtreehouse博客JSON代碼來這裏做工精細的工作：

http://blog.teamtreehouse.com/api/get_recent_summary/

所以這個工作得很好。我讓我的JSON代碼看起來幾乎完全像這個代碼。該數組嵌套使用相同的，相同的命名約定...等等。

這裏是我的JSONcode帶來回來時，它在我的Android代碼插入例外。

http://www.evotechmachine.com/api/get_recent_posts/?include=title,url,status,id,date

如果你比較兩個JSON代碼，你會看到，他們幾乎就在裏面一樣。我在參考的唯一的東西是帖子，標題和網址。我相信它不是名稱不匹配。我處於全面虧損狀態。在此先感謝人。

public static final int NUMBER_OF_POSTS = 20; 
public static final String TAG = MainListActivity.class.getSimpleName(); 
protected JSONObject mBlogData; 
protected ProgressBar mProgressBar; 
private final String KEY_TITLE = "title"; 
private final String KEY_AUTHOR = "author"; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main_list); 

    mProgressBar = (ProgressBar) findViewById(R.id.progressBar1); 


    if (isNetworkAvailable()) { 
    mProgressBar.setVisibility(View.VISIBLE); 
     GetBlogPostsTask getBlogPostsTask = new GetBlogPostsTask(); 
    getBlogPostsTask.execute(); 
    } 
    else {Toast.makeText(this, "network is unavailable", Toast.LENGTH_LONG).show(); 

    } 
    // Toast.makeText(this, message, Toast.LENGTH_LONG).show(); 
} 
@Override 
protected void onListItemClick(ListView l, View v, int position, long id) { 
     super.onListItemClick(l, v, position, id); 
     JSONArray jsonPosts; 
     try { 
      jsonPosts = mBlogData.getJSONArray("posts");    
      JSONObject jsonPost = jsonPosts.getJSONObject(position); 
      String blogUrl = jsonPost.getString("url"); 
      Intent intent = new Intent(this, BlogWebViewActivity.class); 
      intent.setData(Uri.parse(blogUrl)); 
      startActivity(intent); 
     } catch (JSONException e) { 
      logException(e); 
     } 

} 
private void logException(Exception e) { 
    Log.e(TAG, "Exception caught!", e); 
} 

private boolean isNetworkAvailable() { 
    ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); 

    NetworkInfo networkInfo = manager.getActiveNetworkInfo(); 

    boolean isAvailable = false; 
    if (networkInfo != null && networkInfo.isConnected()) { 
     isAvailable = true; 
    } 
    return isAvailable; 
    } 


@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 
public void handleBlogResponse() { 
    mProgressBar.setVisibility(View.INVISIBLE); 
    if(mBlogData==null) { 
     updateDisplayForError(); 
    } 
    else { 
     try { 
     JSONArray jsonPosts = mBlogData.getJSONArray("posts"); 
     ArrayList<HashMap<String, String>> blogPosts = 
       new ArrayList<HashMap<String, String>>(); 

     for (int i = 0;i< jsonPosts.length();i++) { 
      JSONObject post = jsonPosts.getJSONObject(i); 
      String title = post.getString(KEY_TITLE); 
      title = Html.fromHtml(title).toString(); 
      String author = post.getString(KEY_AUTHOR); 
      author = Html.fromHtml(author).toString();   

      HashMap<String, String> blogPost = new HashMap<String, String>(); 
      blogPost.put(KEY_TITLE, title); 
      blogPost.put(KEY_AUTHOR, author); 

      blogPosts.add(blogPost); 

     } 

     String[] keys= { KEY_TITLE, KEY_AUTHOR }; 
     int[] ids = {android.R.id.text1, android.R.id.text2}; 
     SimpleAdapter adapter = new SimpleAdapter(this, blogPosts, android.R.layout.simple_list_item_2, keys, ids); 
     setListAdapter(adapter); 
     } catch (JSONException e) { 
      logException(e); 
     } 
    } 

} 


private void updateDisplayForError() { 
    AlertDialog.Builder builder = new AlertDialog.Builder(this); 
    builder.setTitle(getString(R.string.error_title)); 
    builder.setMessage(getString(R.string.error_message)); 

    builder.setPositiveButton(android.R.string.ok, null); 
    AlertDialog dialog = builder.create(); 
    dialog.show(); 

    TextView emptyTextView = (TextView) getListView().getEmptyView(); 
    emptyTextView.setText(getString(R.string.no_items)); 
}  
private class GetBlogPostsTask extends AsyncTask<Object, Void, JSONObject> { 

    @Override 
    protected JSONObject doInBackground(Object... arg0) { 
     int responseCode = -1; 
     JSONObject jsonResponse = null; 
     try { 
      URL blogFeedUrl = new URL("http://www.evotechmachine.com/api/get_recent_posts/?include=title,url,status,id,date"); 
      HttpURLConnection connection = (HttpURLConnection) blogFeedUrl.openConnection(); 
      connection.connect(); 

      responseCode = connection.getResponseCode(); 
      if (responseCode == HttpURLConnection.HTTP_OK){ 
       InputStream inputStream = connection.getInputStream(); 
       Reader reader = new InputStreamReader(inputStream); 
       int contentLength = connection.getContentLength(); 
       char[] charArray = new char[contentLength]; 
       reader.read(charArray); 
       String responseData = new String(charArray); 

       jsonResponse = new JSONObject(responseData); 

      } else { 
       Log.i(TAG, "unsuccessful HTTP Response Code: " +responseCode); 
      } 
      Log.i(TAG, "Code: " + responseCode); 
     } catch (MalformedURLException e) { 

      logException(e);} 
    catch (IOException e) { 
     logException(e);  
    } 
     catch (Exception e) { 
      logException(e); 
     }   

     return jsonResponse; 
    } 

    @Override 
    protected void onPostExecute(JSONObject result) { 
     mBlogData = result; 

     handleBlogResponse(); 
    } 
}

}

這裏的logcat的：

07-31 20:49:08.209: E/(32544): <s3dReadConfigFile:75>: Can't open file for reading 
07-31 20:49:08.209: E/(32544): <s3dReadConfigFile:75>: Can't open file for reading 
07-31 20:49:09.280: E/MainListActivity(32544): Exception caught! 
07-31 20:49:09.280: E/MainListActivity(32544): java.lang.NegativeArraySizeException: -1 
07-31 20:49:09.280: E/MainListActivity(32544): at com.nibbdigital.blogreader.MainListActivity$GetBlogPostsTask.doInBackground(MainListActivity.java:168) 
07-31 20:49:09.280: E/MainListActivity(32544): at com.nibbdigital.blogreader.MainListActivity$GetBlogPostsTask.doInBackground(MainListActivity.java:1) 
07-31 20:49:09.280: E/MainListActivity(32544): at android.os.AsyncTask$2.call(AsyncTask.java:287) 
07-31 20:49:09.280: E/MainListActivity(32544): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305) 
07-31 20:49:09.280: E/MainListActivity(32544): at java.util.concurrent.FutureTask.run(FutureTask.java:137) 
07-31 20:49:09.280: E/MainListActivity(32544): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230) 
07-31 20:49:09.280: E/MainListActivity(32544): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076) 
07-31 20:49:09.280: E/MainListActivity(32544): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569) 
07-31 20:49:09.280: E/MainListActivity(32544): at java.lang.Thread.run(Thread.java:856)

來源

2013-08-01 Nibb

它可以幫助發佈錯誤的堆棧跟蹤和工具/你用來解析JSON的代碼。 – Androiderson

我添加了活動文件以及日誌文件（僅顯示錯誤）。可以在活動文件代碼 – Nibb

下3/4找到提要URL。我指出活動文件中的第168行是這一行char [] charArray = new char [contentLength]; – Nibb

您的內容長度爲負（即未知）

退房這對於一些見解

https://stackoverflow.com/a/5428670/770467

希望它能幫助

來源

2013-08-01 02:08:38 Androiderson

INT CONTENTLENGTH = connection.getContentLength（）; 收益負長度

這是因爲你的服務器沒有設置HTTP響應的Content-Length頭。所以兩個解決方案：1。您可以修復服務器端代碼 2.您可以處理輸入響應這種方式來轉換爲字符串：

BufferedReader br = null; 
    try 
    { 
     br = new BufferedReader(new InputStreamReader(inputStream); 
     StringBuilder sb = new StringBuilder(); 
     for (String line; (line = br.readLine()) != null;) { 
     sb.append(line); 
     sb.append("\n"); 
     } 

     return sb.toString(); 
    } 
    finally 
    { 
     if (reader != null) { 
       reader.close(); 
     } 
    }

來源

2013-08-01 02:19:43 Pradeep

謝謝。我會給它一個鏡頭 – Nibb

JSON數據不會加載到我的Android應用程序

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