Question

I have a JSON string which is generated by a php file. The problem is that the JSON string is not appearing on the textview of android. can anyone explain why?

public class AllUsersActivity extends ListActivity {

// Progress Dialog
private ProgressDialog pDialog;

// Creating JSON Parser object
JSONParser jParser = new JSONParser();

ArrayList<HashMap<String, String>> usersList;

// url to get all users list
private static String url_all_users = "http://10.0.2.2/android_connect/get_all_users.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_USERS = "users";
private static final String TAG_UID = "UserID";
private static final String TAG_FIRSTNAME = "FirstName";

// users JSONArray
JSONArray users = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.all_users);

    // Hashmap for ListView
    usersList = new ArrayList<HashMap<String, String>>();

    // Loading users in Background Thread
    new LoadAllusers().execute();

    // Get listview
    ListView lv = getListView();

    // on seleting single product
    // launching Edit Product Screen
    lv.setOnItemClickListener(new OnItemClickListener() {

        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
            // getting values from selected ListItem
            String uid = ((TextView) view.findViewById(R.id.uid)).getText()
                    .toString();

            // Starting new intent
            Intent in = new Intent(getApplicationContext(),
                    UserDetailsActivity.class);
            // sending uid to next activity
            in.putExtra(TAG_UID, uid);

            // starting new activity and expecting some response back
            startActivityForResult(in, 100);
        }
    });

}


/**
 * Background Async Task to Load all product by making HTTP Request
 * */
class LoadAllusers extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(AllUsersActivity.this);
        pDialog.setMessage("Loading users. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(false);
        pDialog.show();
    }

    /**
     * getting All users from url
     * */
    protected String doInBackground(String... args) {
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        // getting JSON string from URL
        JSONObject json = jParser.makeHttpRequest(url_all_users, "GET", params);

        // Check your log cat for JSON reponse
        Log.d("All users: ", json.toString());

        try {
            // Checking for SUCCESS TAG
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                // users found
                // Getting Array of users
                users = json.getJSONArray(TAG_USERS);

                // looping through All users
                for (int i = 0; i < users.length(); i++) {
                    JSONObject c = users.getJSONObject(i);

                    // Storing each json item in variable
                    String id = c.getString(TAG_UID);
                    String name = c.getString(TAG_FIRSTNAME);

                    // creating new HashMap
                    HashMap<String, String> map = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    map.put(TAG_UID, id);
                    map.put(TAG_FIRSTNAME, name);

                    // adding HashList to ArrayList
                    usersList.add(map);
                }
            } 
        } 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 users
        pDialog.dismiss();
        // updating UI from Background Thread
        runOnUiThread(new Runnable() {
            public void run() {
                /**
                 * Updating parsed JSON data into ListView
                 * */
                ListAdapter adapter = new SimpleAdapter(
                        AllUsersActivity.this, usersList,
                        R.layout.list_item, new String[] { TAG_UID,
                                TAG_FIRSTNAME},
                        new int[] { R.id.uid, R.id.name });
                // updating listview
                setListAdapter(adapter);
            }
        });

    }

}
}

this is the JSON string from the PHP file

{"Users":[{"0":[],"UserID":"1","FirstName":"lalawee","Email":"12345","Password":null},{"0":[],"UserID":"2","FirstName":"shadowblade721","Email":"12345","Password":null,"1":[]},{"0":[],"UserID":"3","FirstName":"dingdang","Email":"12345","Password":null,"1":[],"2":[]},{"0":[],"UserID":"4","FirstName":"solidsnake0328","Email":"12345","Password":null,"1":[],"2":[],"3":[]}],"success":1}

Answer 1

I’ve found the error.

It is caused by case sensitiveness.

users –> Users

Mistake on my part. Sorry.

Thanks for trying to help me!