title: FATAL EXCEPTION: AsyncTask, receiving json
body: <p>Im doing some database work in my app, i want to pull all the locations from my web database and show it in my listview in the app. Ive created the "API" where the respons is Json.</p>
  
  <p>The link where the json is: <a href="http://000100023.host56.com/db_all.php" rel="nofollow">http://000100023.host56.com/db_all.php</a></p>
  
  <p>Using this tutorial: <a href="http://www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/" rel="nofollow">http://www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/</a></p>
  
  <p>The Logcat:</p>
  
  <pre><code>11-14 16:50:21.508: E/AndroidRuntime(22809): FATAL EXCEPTION: AsyncTask #1
  11-14 16:50:21.508: E/AndroidRuntime(22809): Process: com.spxc.nightclubratings, PID: 22809
  11-14 16:50:21.508: E/AndroidRuntime(22809): java.lang.RuntimeException: An error occured while executing doInBackground()
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at android.os.AsyncTask$3.done(AsyncTask.java:300)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at java.util.concurrent.FutureTask.run(FutureTask.java:242)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at java.lang.Thread.run(Thread.java:841)
  11-14 16:50:21.508: E/AndroidRuntime(22809): Caused by: java.lang.NullPointerException
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at com.spxc.nightclubratings.SearchLocationActivity$LoadAllProducts.doInBackground(SearchLocationActivity.java:132)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at com.spxc.nightclubratings.SearchLocationActivity$LoadAllProducts.doInBackground(SearchLocationActivity.java:1)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at android.os.AsyncTask$2.call(AsyncTask.java:288)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    at java.util.concurrent.FutureTask.run(FutureTask.java:237)
  11-14 16:50:21.508: E/AndroidRuntime(22809):    ... 4 more
  11-14 16:50:22.199: E/WindowManager(22809): android.view.WindowLeaked: Activity com.spxc.nightclubratings.SearchLocationActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{42313208 V.E..... R......D 0,0-729,192} that was originally added here
  11-14 16:50:22.199: E/WindowManager(22809):     at android.view.ViewRootImpl.&lt;init&gt;(ViewRootImpl.java:346)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:248)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.app.Dialog.show(Dialog.java:286)
  11-14 16:50:22.199: E/WindowManager(22809):     at com.spxc.nightclubratings.SearchLocationActivity$LoadAllProducts.onPreExecute(SearchLocationActivity.java:119)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:587)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.os.AsyncTask.execute(AsyncTask.java:535)
  11-14 16:50:22.199: E/WindowManager(22809):     at com.spxc.nightclubratings.SearchLocationActivity.onCreate(SearchLocationActivity.java:59)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.app.Activity.performCreate(Activity.java:5243)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2140)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.app.ActivityThread.access$700(ActivityThread.java:135)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.os.Handler.dispatchMessage(Handler.java:102)
  **11-14 16:50:22.199: E/WindowManager(22809):   at android.os.Looper.loop(Looper.java:137)
  11-14 16:50:22.199: E/WindowManager(22809):     at android.app.ActivityThread.main(ActivityThread.java:4998)
  11-14 16:50:22.199: E/WindowManager(22809):     at java.lang.reflect.Method.invokeNative(Native Method)
  11-14 16:50:22.199: E/WindowManager(22809):     at java.lang.reflect.Method.invoke(Method.java:515)
  11-14 16:50:22.199: E/WindowManager(22809):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
  11-14 16:50:22.199: E/WindowManager(22809):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
  11-14 16:50:22.199: E/WindowManager(22809):     at dalvik.system.NativeStart.main(Native Method)
  </code></pre>
  
  <p>JsonParser:
      public class JSONParser {</p>
  
  <pre><code>    static InputStream is = null;
      static JSONObject jObj = null;
      static String json = "";
  
      // constructor
      public JSONParser() {
  
      }
  
      // function get json from url
      // by making HTTP POST or GET mehtod
      public JSONObject makeHttpRequest(String url, String method,
              List&lt;NameValuePair&gt; params) {
  
          // Making HTTP request
          try {
  
              // check for request method
              if(method == "POST"){
                  // request method is POST
                  // defaultHttpClient
                  DefaultHttpClient httpClient = new DefaultHttpClient();
                  HttpPost httpPost = new HttpPost(url);
                  httpPost.setEntity(new UrlEncodedFormEntity(params));
  
                  HttpResponse httpResponse = httpClient.execute(httpPost);
                  HttpEntity httpEntity = httpResponse.getEntity();
                  is = httpEntity.getContent();
  
              }else if(method == "GET"){
                  // request method is GET
                  DefaultHttpClient httpClient = new DefaultHttpClient();
                  String paramString = URLEncodedUtils.format(params, "utf-8");
                  url += "?" + paramString;
                  HttpGet httpGet = new HttpGet(url);
  
                  HttpResponse httpResponse = httpClient.execute(httpGet);
                  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>SearchLocationAcitivity:</p>
  
  <pre><code>public class SearchLocationActivity extends ListActivity {
  
      // Progress Dialog
      private ProgressDialog pDialog;
  
      // Creating JSON Parser object
      JSONParser jParser = new JSONParser();
  
      ArrayList&lt;HashMap&lt;String, String&gt;&gt; productsList;
  
      // url to get all products list
      private static String url_all_products = "http://http://000100023.host56.com/db_all.php";
  
      // JSON Node names
      private static final String TAG_SUCCESS = "success";
      private static final String TAG_PRODUCTS = "locations";
      private static final String TAG_PID = "id";
      private static final String TAG_NAME = "name";
  
      // products JSONArray
      JSONArray products = null;
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_search_location);
  
          // Hashmap for ListView
          productsList = new ArrayList&lt;HashMap&lt;String, String&gt;&gt;();
  
          // Loading products in Background Thread
          new LoadAllProducts().execute();
  
          // Get listview
          ListView lv = getListView();
  
          // on seleting single product
          // launching Edit Product Screen
          lv.setOnItemClickListener(new OnItemClickListener() {
  
              @Override
              public void onItemClick(AdapterView&lt;?&gt; parent, View view,
                      int position, long id) {
                  // getting values from selected ListItem
                  String pid = ((TextView) view.findViewById(R.id.pid)).getText()
                          .toString();
  
                  // Starting new intent
                  //Intent in = new Intent(getApplicationContext(),
                    //      EditProductActivity.class);
                  // sending pid to next activity
                  //in.putExtra(TAG_PID, pid);
  
                  // starting new activity and expecting some response back
                  //startActivityForResult(in, 100);
              }
          });
  
      }
  
      // Response from Edit Product Activity
      @Override
      protected void onActivityResult(int requestCode, int resultCode, Intent data) {
          super.onActivityResult(requestCode, resultCode, data);
          // if result code 100
          if (resultCode == 100) {
              // if result code 100 is received
              // means user edited/deleted product
              // reload this screen again
              Intent intent = getIntent();
              finish();
              startActivity(intent);
          }
  
      }
  
      /**
       * Background Async Task to Load all product by making HTTP Request
       * */
      class LoadAllProducts extends AsyncTask&lt;String, String, String&gt; {
  
          /**
           * Before starting background thread Show Progress Dialog
           * */
          @Override
          protected void onPreExecute() {
              super.onPreExecute();
              pDialog = new ProgressDialog(SearchLocationActivity.this);
              pDialog.setMessage("Loading locations. Please wait...");
              pDialog.setIndeterminate(false);
              pDialog.setCancelable(false);
              pDialog.show();
          }
  
          /**
           * getting All products from url
           * */
          protected String doInBackground(String... args) {
              // Building Parameters
              List&lt;NameValuePair&gt; params = new ArrayList&lt;NameValuePair&gt;();
              // getting JSON string from URL
              JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
  
              // Check your log cat for JSON reponse
              Log.d("All Products: ", json.toString());
  
              try {
                  // Checking for SUCCESS TAG
                  int success = json.getInt(TAG_SUCCESS);
  
                  if (success == 1) {
                      // products found
                      // Getting Array of Products
                      products = json.getJSONArray(TAG_PRODUCTS);
  
                      // looping through All Products
                      for (int i = 0; i &lt; products.length(); i++) {
                          JSONObject c = products.getJSONObject(i);
  
                          // Storing each json item in variable
                          String id = c.getString(TAG_PID);
                          String name = c.getString(TAG_NAME);
  
                          // creating new HashMap
                          HashMap&lt;String, String&gt; map = new HashMap&lt;String, String&gt;();
  
                          // adding each child node to HashMap key =&gt; value
                          map.put(TAG_PID, id);
                          map.put(TAG_NAME, name);
  
                          // adding HashList to ArrayList
                          productsList.add(map);
                      }
                  } else {
                      // no products found
                      // Launch Add New product Activity
                      //Intent i = new Intent(getApplicationContext(),
                        //      NewProductActivity.class);
                      // Closing all previous activities
                      //i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                      //startActivity(i);
                  }
              } catch (JSONException e) {
                  e.printStackTrace();
              }
  
              return null;
          }
  
          /**
           * After completing background task Dismiss the progress dialog
           * **/
          protected void onPostExecute(String file_url) {
              // dismiss the dialog after getting all products
              pDialog.dismiss();
              // updating UI from Background Thread
              runOnUiThread(new Runnable() {
                  public void run() {
                      /**
                       * Updating parsed JSON data into ListView
                       * */
                      ListAdapter adapter = new SimpleAdapter(
                              SearchLocationActivity.this, productsList,
                              R.layout.list_item, new String[] { TAG_PID,
                                      TAG_NAME},
                              new int[] { R.id.pid, R.id.name });
                      // updating listview
                      setListAdapter(adapter);
                  }
              });
  
          }
  
      }
  }
  </code></pre>
  
  <p>Any help is much appreciated!</p>