I am working on activity which request one php file on server & this php file will return me one JSONArray having JSONObjects as its elements. I get this jArray & extract out its contents  e.g., all jsonObjects. each jsonObject have data of one specific user like uniqueId, name, address, contact details etc... I showed a list of all users. I need when I click on list item it will show me complete profile of the concern user...& for that i put these extracted jsonObjects in another JSONObject having uniqueId as name & the corresponding extracted jsonObject as its value. 
My list :
this!
When i click on one item of this list I get its uniqueId what I need is, all keys of jsonObject having JsonObject as its values. 
    public void onItemClick(AdapterView<?> arg0, View arg1, int position, long id) {
    ItemBean bean = (ItemBean) adapter.getItem(position);   
    Toast.makeText(this," FanId => " + bean.getUid() +" \n FanName => " + bean.getTitle(), 
                Toast.LENGTH_SHORT).show();
    Iterator<String> userKeys=extracted();//here i get-> Null PointerException!
        while(fKeys.hasNext()){
            System.out.println("Key:"+userKeys.next());
        }
  }
    //iterator that return me keys(e.g., all uids of users) 
    @SuppressWarnings("unchecked")
    private Iterator<String> extracted() {
        Iterator<String> keys = jFansData.keys();
        return keys;
    }
    12-10 20:45:55.833: ERROR/AndroidRuntime(907): Caused by:  java.lang.NullPointerException
    12-10 20:45:55.833: ERROR/AndroidRuntime(907): at com.technotalkative.listview5.MainActivity.extracted(MainActivity.java:87)
    12-10 20:45:55.833: ERROR/AndroidRuntime(907): at com.technotalkative.listview5.MainActivity.onCreate(MainActivity.java:51)
    12-10 20:45:55.833: ERROR/AndroidRuntime(907): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
I am not getting what I do wrong over here, any solution please...
Here is the Complete Code Of My Class->
public class MainActivity extends Activity implements OnItemClickListener {
String url,fd;
ListView mFansListView;
JSONObject jFan_Data;//contain data of an indivisual fan
JSONObject jFansData;//contain data of an all fans
ListViewCustomAdapter adapter;
LayoutInflater lInflater;
private ArrayList<Object> fansList;
private ItemBean bean;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    prepareArrayLits();
    mFansListView = (ListView) findViewById(android.R.id.list);
    adapter = new ListViewCustomAdapter(this, fansList);
    mFansListView.setAdapter(adapter);//come null pointer exception when no fan data is returned! hendle it...
    mFansListView.setOnItemClickListener(this);
}
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int position, long id) {
    // TODO Auto-generated method stub
    ItemBean bean = (ItemBean) adapter.getItem(position);
    Toast.makeText(this," FanId => " + bean.getUid() +" \n UID => " + bean.getTitle(), Toast.LENGTH_SHORT).show(); 
    Iterator<String> fKeys=extracted();
    while(fKeys.hasNext()){
        System.out.println("Key:"+fKeys.next());
    }
}
//....................................................................
//iterator that return me keys(e.g., all uids of fans) through which i match clicked lists id
  @SuppressWarnings("unchecked")
private Iterator<String> extracted() {
            Iterator<String> keys = jFansData.keys();//I get NullPointerExcertion over here...???
    return keys;
}
//.............................................................................
/* *Method used to prepare the ArrayList,
 */
public void prepareArrayLits()
{
    url="http://192.168.200.111/ManU/location1_and.php";
    HttpClient client = new DefaultHttpClient();
    HttpConnectionParams.setConnectionTimeout(client.getParams(), 10000);
    HttpResponse response;
    JSONObject json = new JSONObject();
 try {
    HttpPost post=new HttpPost(url);
     /**! Currently all these parameters are hard coded... 
      * In future i have to use services of LocationManager to get my current location!
      */
     json.put("radius", 1000);
     json.put("lat", 12.9716060);
     json.put("lang", 77.5903760);
     json.put("myid", "h9ow0");
        post.setHeader("json", json.toString());
        StringEntity se=new StringEntity(json.toString());
        se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
        post.setEntity(se);
        response=client.execute(post);
       /* Checking response */
        // Get the data in the entity
        InputStream in=response.getEntity().getContent(); 
        //convert it to string... 
         fd=convertStreamToString(in);
        Log.i("Read from Server", fd);
      //Checking that fd is array containing data of all users or have no data...
        String no_data="No Data"; 
          if(no_data==fd){
              Log.i("NoRecords", "No Users Near you... Try over long distance!");
              }else {    
               JSONArray jArray = new JSONArray(fd);//contain array returned by "php" having data of all users
                   try{
                    fansList = new ArrayList<Object>();
                      for(int i=0;i<jArray.length();i++){
                        //will return the data of each row fetched from JSONArray returned by location1.php
                          String data_of_each_user=jArray.get(i).toString();
                        Log.i("Data Of User at index "+i+" is", data_of_each_user);
                         //I put the object at index "i" into JSONObject & retrieve data from name-value pair
                          jFan_Data=jArray.getJSONObject(i);//data of User at index i in array
                        AddObjectToList(jFan_Data.getString("uniqid").toString(),R.drawable.ic_add, jFan_Data.getString("name"), jFan_Data.getString("distance"));
                     try{
                            /** this JSONObject hold data of all users taking UniqueId of user as key & 
                             * JSONObject at index i in the array returned by the php as the value!!! */      
                               jFansData.put(jFan_Data.get("uniqid").toString(), jFan_Data);//why i getting NullPointerException Over Here...???
                          } catch (Exception e) {
                             // TODO: handle exception
                             e.printStackTrace(); 
                         }
                       }
                     } catch (Exception e) {
                         // TODO: handle exception
                         e.printStackTrace(); 
                     }
                }   
     } catch (Exception e) {
       // TODO: handle exception
       e.printStackTrace(); 
    }
}
//..............................................................................
// Add one item into the Array List
public void AddObjectToList(String uid,int image, String title, String desc)
{
    bean = new ItemBean();
    bean.setUid(uid);
    bean.setDescription(desc);
    bean.setImage(image);
    bean.setTitle(title);
    fansList.add(bean);
}
// -------------------------------------------------------------------------
//convert respons into human readable formate
private static String convertStreamToString(InputStream is) {
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    StringBuilder sb = new StringBuilder();
    String line = null;
    try {
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return sb.toString();
 }
}
as i mentioned above, I need to show the complete profile of the user when i click on list item... So, What i do to solve this problem!!! ???
 
    