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POandroid facing nullpoint exception while Parsing json object from an url into listview
 

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  1. POandroid facing nullpoint exception while Parsing json object from an url into listview
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    <p>I am trying to parse json object to populate it into list view,but i am facing some problem please help</p> <p>I am getting NullpointerException</p> <p>here is my full code:</p> <p>I am parsing data from the following url</p> <p><a href="http://www.kaverisoft.com/careers/assignments/android/a1.json" rel="nofollow">URL I AM PARSING IS</a></p> <p>code for parsing data </p> <pre><code> public class JSONParser { static InputStream is = null; static JSONObject jObj = null; static String json = ""; public JSONParser(){ } public JSONObject getJSONFromUrl(String url){ //making Http request try{ //default httpclient DefaultHttpClient httpClient = new DefaultHttpClient(); HttpPost httpPost = new HttpPost(url); HttpResponse httpResponse = httpClient.execute(httpPost); HttpEntity httpEntity = httpResponse.getEntity(); is = httpEntity.getContent(); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } catch (ClientProtocolException e) { e.printStackTrace(); } catch(IOException e){ e.printStackTrace(); } try{ BufferedReader reader = new BufferedReader(new InputStreamReader( is, "iso-8859-1"), 8); StringBuilder sb = new StringBuilder(); String line = null; while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } is.close(); json = sb.toString(); } catch (Exception e) { Log.e("Buffer Error", "Error converting result " + e.toString()); } // try parse the string to a JSON object try { jObj = new JSONObject(json); } catch (JSONException e) { Log.e("JSON Parser", "Error parsing data " + e.toString()); } // return JSON String return jObj; } </code></pre> <p>}</p> <pre><code>here is activity code public class AndroidJSONParsingActivity extends ListActivity { // url to make request private static String url = "http://www.kaverisoft.com/careers/assignments/android/a1.php"; // JSON NAme Node private static final String TAG_BOOK = "book"; private static final String TAG_ID = "id"; private static final String TAG_TITLE = "title"; private static final String TAG_AUTHORS = "authors"; private static final String TAG_DESCRIPTION = "description"; private static final String TAG_PRICE = "price"; //Book JSONArray JSONArray book = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // HashMap for ListView ArrayList&lt;HashMap&lt;String, String&gt;&gt; bookList = new ArrayList&lt;HashMap&lt;String, String&gt;&gt;(); // creating Json parser instance JSONParser jParser = new JSONParser(); // getting Json String from url JSONObject json = jParser.getJSONFromUrl(url); try{ // getting array of books book = json.getJSONArray(TAG_BOOK); // looping through all books for(int i=0;i&lt;book.length();i++){ JSONObject c = book.getJSONObject(i); // storing each json item in variable String title = c.getString(TAG_TITLE); String price = c.getString(TAG_PRICE); String authors = c.getString(TAG_AUTHORS); String id = c.getString(TAG_ID); String description = c.getString(TAG_DESCRIPTION); // creating new HashMap HashMap&lt;String, String&gt; map = new HashMap&lt;String, String&gt;(); map.put(TAG_ID, id); map.put(TAG_TITLE, title); map.put(TAG_PRICE, price); map.put(TAG_AUTHORS, authors); map.put(TAG_DESCRIPTION, description); bookList.add(map); } } catch (JSONException e) { e.printStackTrace(); } // Updating Parsed Data into ListView ListAdapter adapter = new SimpleAdapter(this, bookList, R.layout.list_item, new String[]{TAG_TITLE,TAG_DESCRIPTION,TAG_AUTHORS } , new int[] { R.id.title,R.id.description,R.id.author }); setListAdapter(adapter); // selecting single list view item ListView lv = getListView(); // Launching new screen on Selecting Single ListItem lv.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView&lt;?&gt; parent, View view, int position, long id) { // getting values from selected ListItem String title = ((TextView) view.findViewById(R.id.title)).getText().toString(); String authors = ((TextView) view.findViewById(R.id.author)).getText().toString(); String description = ((TextView) view.findViewById(R.id.description)).getText().toString(); // Starting new intent Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class); in.putExtra(TAG_TITLE, title); in.putExtra(TAG_AUTHORS, authors); in.putExtra(TAG_DESCRIPTION, description); startActivity(in); } }); } </code></pre> <p>}</p> <p>I am trying to parse only book object </p> <p>Please solve my problem.</p> <p>LogCat detail's </p> <pre><code>08-24 00:56:48.202: W/dalvikvm(949): threadid=1: thread exiting with uncaught exception (group=0x4001d800) 08-24 00:56:48.263: E/AndroidRuntime(949): FATAL EXCEPTION: main 08-24 00:56:48.263: E/AndroidRuntime(949): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.sree.androidjsonparser/com.sree.androidjsonparser.AndroidJSONParsingActivity}: java.lang.NullPointerException 08-24 00:56:48.263: E/AndroidRuntime(949): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 08-24 00:56:48.263: E/AndroidRuntime(949): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 08-24 00:56:48.263: E/AndroidRuntime(949): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 08-24 00:56:48.263: E/AndroidRuntime(949): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 08-24 00:56:48.263: E/AndroidRuntime(949): at android.os.Handler.dispatchMessage(Handler.java:99) 08-24 00:56:48.263: E/AndroidRuntime(949): at android.os.Looper.loop(Looper.java:123) 08-24 00:56:48.263: E/AndroidRuntime(949): at android.app.ActivityThread.main(ActivityThread.java:4627) 08-24 00:56:48.263: E/AndroidRuntime(949): at java.lang.reflect.Method.invokeNative(Native Method) 08-24 00:56:48.263: E/AndroidRuntime(949): at java.lang.reflect.Method.invoke(Method.java:521) 08-24 00:56:48.263: E/AndroidRuntime(949): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 08-24 00:56:48.263: E/AndroidRuntime(949): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 08-24 00:56:48.263: E/AndroidRuntime(949): at dalvik.system.NativeStart.main(Native Method) 08-24 00:56:48.263: E/AndroidRuntime(949): Caused by: java.lang.NullPointerException 08-24 00:56:48.263: E/AndroidRuntime(949): at com.sree.androidjsonparser.AndroidJSONParsingActivity.onCreate(AndroidJSONParsingActivity.java:62) 08-24 00:56:48.263: E/AndroidRuntime(949): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 08-24 00:56:48.263: E/AndroidRuntime(949): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 08-24 00:56:48.263: E/AndroidRuntime(949): ... 11 more 08-24 00:56:53.812: I/Process(949): Sending signal. PID: 949 SIG: 9 </code></pre>
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    1. COPlease post the LogCat errors and if you can read the logcat indicate which line the NullPointerException occurs on.
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      1. USSam
    2. COWhat is line 62 in `AndroidJSONParsingActivity.java`?
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      1. USEric
 

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