title: how to correct Error parsing data : must begin with JsonObject text '{'"?
body: <p>EnregistrerActivity.java  – Activity to handle registration event</p>
  
  <pre><code>package tn.pack.ordre.enregistrer;
  
      import org.json.JSONException;
      import org.json.JSONObject;
  
      import tn.pack.ordre.enregistrer.UserFunctions;
  
      import tn.pack.ordre.R;
      import android.app.Activity;
      import android.content.Intent;
      import android.os.Bundle;
      import android.view.View;
      import android.widget.EditText;
      import android.widget.TextView;
  
      public class EnregistrerActivity extends Activity {
  
  
  
         /** Called when the activity is first created. */
          @Override
        public void onCreate(Bundle savedInstanceState) {
              super.onCreate(savedInstanceState);
               // Fixe la mise en page d’une activité
              setContentView(R.layout.inscription);
  
          } 
  
  
  
        public void btn_valider(View v) {     
  
            String  userName=((EditText)findViewById(R.id.et_un)).getText().toString();
            String  password=((EditText)findViewById(R.id.et_pw)).getText().toString();
            String  cin=((EditText) findViewById(R.id.et_cin)).getText().toString();
  
  
              UserFunctions userFunction = new UserFunctions();
              JSONObject json = userFunction.registerUser(userName,cin,password);
              TextView errorE = (TextView)findViewById(R.id.textViewerrer);
  
              try {
  
  
                  if (json.getString("success") != null) {
  
                      String res = json.getString("success");
                      if (Integer.parseInt(res) == 1) {
  
                          errorE.setText("enregistrement ok");
  
  
                      } else {
                          errorE.setText("erreur pendant l'enregistrement");
  
  
                      }
                  }
              } catch (JSONException e) {
                  e.printStackTrace();
                  System.out.println("btnRegister:  "+e.toString());
              }
  
  
           }
  
        public void Annuler(View v) {
  
                          startActivity(new Intent(getApplicationContext(),LoginActivity.class));
  
                         }
      }
  </code></pre>
  
  <p>UserFunctions.java -In this class all the functions will interact with JSONParser</p>
  
  <pre><code>package tn.pack.ordre.enregistrer;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.http.NameValuePair;
  import org.apache.http.message.BasicNameValuePair;
  import org.json.JSONObject;
  
  public class UserFunctions {
  
      private JSONParser jsonParser;
  
      private static String loginURL = "http://10.0.2.2/webservice/index.php";
      private static String registerURL = loginURL;
  
      private static String login_tag = "login";
      private static String register_tag = "register";
  
      // constructor
      public UserFunctions(){
          jsonParser = new JSONParser();
      }
  
  
      public JSONObject loginUser(String userName, String password){
          // Building Parameters
          List&lt;NameValuePair&gt; params = new ArrayList&lt;NameValuePair&gt;();
          params.add(new BasicNameValuePair("tag", login_tag));
          params.add(new BasicNameValuePair("userName", userName));
          params.add(new BasicNameValuePair("password", password));
          JSONObject json = jsonParser.getJSONFromUrl(loginURL, params);
  
          return json;
      }
  
  
      /**
       * function make Login Request
       * @param userName
       * @param cin
       * @param password
       * */
  
      public JSONObject registerUser(String userName, String cin,String password){
          // Building Parameters
          List&lt;NameValuePair&gt; params = new ArrayList&lt;NameValuePair&gt;();
          params.add(new BasicNameValuePair("tag", register_tag));
          params.add(new BasicNameValuePair("userName", userName));
          params.add(new BasicNameValuePair("cin", cin));
          params.add(new BasicNameValuePair("password", password));
  
          // getting JSON Object
          JSONObject json = jsonParser.getJSONFromUrl(registerURL, params);
  
          // return json
          return json;
      }
  
  
  }
  </code></pre>
  
  <p>JSONParser.java -to parse api response JSON.</p>
  
  <pre><code>package tn.pack.ordre.enregistrer;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.UnsupportedEncodingException;
  import java.util.List;
  
  import org.apache.http.HttpEntity;
  import org.apache.http.HttpResponse;
  import org.apache.http.NameValuePair;
  import org.apache.http.client.ClientProtocolException;
  import org.apache.http.client.entity.UrlEncodedFormEntity;
  import org.apache.http.client.methods.HttpPost;
  import org.apache.http.impl.client.DefaultHttpClient;
  import org.json.JSONException;
  import org.json.JSONObject;
  
  import android.util.Log;
  
  public class JSONParser {
  
      static InputStream is = null;
      static JSONObject jObj = null;
      static String json = "";
  
      // constructor
      public JSONParser() {
  
      } 
  
      public JSONObject getJSONFromUrl(String url, List&lt;NameValuePair&gt; params) {
  
          // Making HTTP request
          try {
              // 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();
  
          } 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();
              Log.e("JSON", json);
          } 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>errer logCat :
  <strong>E/JSON Parser(261)</strong></p>
  
  <pre><code>    05-22 09:28:44.699: E/Buffer Error(261): Error converting result java.lang.NullPointerException
      05-22 09:28:44.708: E/JSON Parser(261): Error parsing data org.json.JSONException: A JSONObject text must begin with '{' at character 0 of...
      05-22 09:28:44.750: E/AndroidRuntime(261): Uncaught handler: thread main exiting due to uncaught exception
      05-22 09:28:44.798: E/AndroidRuntime(261): java.lang.IllegalStateException: Could not execute method of the activity
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.View$1.onClick(View.java:2031)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.View.performClick(View.java:2364)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.View.onTouchEvent(View.java:4179)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.widget.TextView.onTouchEvent(TextView.java:6541)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.View.dispatchTouchEvent(View.java:3709)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.app.Activity.dispatchTouchEvent(Activity.java:2061)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1691)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.os.Handler.dispatchMessage(Handler.java:99)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.os.Looper.loop(Looper.java:123)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.app.ActivityThread.main(ActivityThread.java:4363)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at java.lang.reflect.Method.invokeNative(Native Method)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at java.lang.reflect.Method.invoke(Method.java:521)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at dalvik.system.NativeStart.main(Native Method)
      05-22 09:28:44.798: E/AndroidRuntime(261): Caused by: java.lang.reflect.InvocationTargetException
      05-22 09:28:44.798: E/AndroidRuntime(261):  at tn.pack.ordre.enregistrer.EnregistrerActivity.btn_valider(EnregistrerActivity.java:45)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at java.lang.reflect.Method.invokeNative(Native Method)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at java.lang.reflect.Method.invoke(Method.java:521)
      05-22 09:28:44.798: E/AndroidRuntime(261):  at android.view.View$1.onClick(View.java:2026)
      05-22 09:28:44.798: E/AndroidRuntime(261):  ... 23 more
      05-22 09:28:44.798: E/AndroidRuntime(261): Caused by: java.lang.NullPointerException
      05-22 09:28:44.798: E/AndroidRuntime(261):  ... 27 more
      05-22 09:37:39.449: E/Buffer Error(354): Error converting result java.lang.NullPointerException
      05-22 09:37:39.449: E/JSON Parser(354): Error parsing data org.json.JSONException: A JSONObject text must begin with '{' at character 0 of 
      05-22 09:37:39.459: E/AndroidRuntime(354): Uncaught handler: thread main exiting due to uncaught exception
      05-22 09:37:39.499: E/AndroidRuntime(354): java.lang.IllegalStateException: Could not execute method of the activity
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.View$1.onClick(View.java:2031)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.View.performClick(View.java:2364)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.View.onTouchEvent(View.java:4179)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.widget.TextView.onTouchEvent(TextView.java:6541)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.View.dispatchTouchEvent(View.java:3709)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.app.Activity.dispatchTouchEvent(Activity.java:2061)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1691)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.os.Handler.dispatchMessage(Handler.java:99)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.os.Looper.loop(Looper.java:123)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.app.ActivityThread.main(ActivityThread.java:4363)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at java.lang.reflect.Method.invokeNative(Native Method)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at java.lang.reflect.Method.invoke(Method.java:521)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at dalvik.system.NativeStart.main(Native Method)
      05-22 09:37:39.499: E/AndroidRuntime(354): Caused by: java.lang.reflect.InvocationTargetException
      05-22 09:37:39.499: E/AndroidRuntime(354):  at tn.pack.ordre.enregistrer.EnregistrerActivity.btn_valider(EnregistrerActivity.java:39)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at java.lang.reflect.Method.invokeNative(Native Method)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at java.lang.reflect.Method.invoke(Method.java:521)
      05-22 09:37:39.499: E/AndroidRuntime(354):  at android.view.View$1.onClick(View.java:2026)
      05-22 09:37:39.499: E/AndroidRuntime(354):  ... 23 more
      05-22 09:37:39.499: E/AndroidRuntime(354): Caused by: java.lang.NullPointerException
      05-22 09:37:39.499: E/AndroidRuntime(354):  at tn.pack.ordre.enregistrer.UserFunctions.registerUser(UserFunctions.java:60)
      05-22 09:37:39.499: E/AndroidRuntime(354):  ... 27 more
  05-22 09:37:39.499: E/AndroidRuntime(354):  ... 27 more
  05-22 09:37:39.539: I/Process(52): Sending signal. PID: 354 SIG: 3
  05-22 09:37:39.539: I/dalvikvm(354): threadid=7: reacting to signal 3
  05-22 09:37:39.709: I/dalvikvm(354): Wrote stack trace to '/data/anr/traces.txt'
  05-22 09:37:42.819: I/Process(354): Sending signal. PID: 354 SIG: 9
  05-22 09:37:42.869: I/WindowManager(52): WIN DEATH: Window{44e2a0e0 tn.pack.ordre/tn.pack.ordre.enregistrer.EnregistrerActivity paused=false}
  05-22 09:37:42.869: I/ActivityManager(52): Process tn.pack.ordre (pid 354) has died.
  05-22 09:37:42.879: I/WindowManager(52): WIN DEATH: Window{44e00b30 tn.pack.ordre/tn.pack.ordre.enregistrer.LoginActivity paused=false}
  05-22 09:37:42.909: I/ActivityManager(52): Start proc tn.pack.ordre for activity tn.pack.ordre/.enregistrer.LoginActivity: pid=363 uid=10028 gids={3003, 1015}
  05-22 09:37:43.119: D/ddm-heap(363): Got feature list request
  05-22 09:37:43.189: I/UsageStats(52): Unexpected resume of tn.pack.ordre while already resumed in tn.pack.ordre
  05-22 09:37:43.349: D/dalvikvm(363): GC freed 719 objects / 54696 bytes in 72ms
  05-22 09:37:45.359: W/InputManagerService(52): Got RemoteException sending setActive(false) notification to pid 354 uid 10028
  05-22 09:37:45.741: I/ActivityManager(52): Displayed activity tn.pack.ordre/.enregistrer.LoginActivity: 2862 ms (total 2862 ms)
  05-22 09:37:46.958: I/ActivityManager(52): Starting activity: Intent { act=android.intent.action.MAIN cat=[android.intent.category.HOME] flg=0x10200000 cmp=com.android.launcher/.Launcher }
  05-22 09:37:47.228: W/InputManagerService(52): Starting input on non-focused client com.android.internal.view.IInputMethodClient$Stub$Proxy@44e3eaf8 (uid=10028 pid=363)
  05-22 09:37:52.699: D/dalvikvm(111): GC freed 164 objects / 6600 bytes in 140ms
  05-22 09:46:00.269: D/dalvikvm(52): GC freed 11198 objects / 572384 bytes in 213ms
  05-22 09:56:13.229: D/dalvikvm(52): threadid=15: bogus mon 1+0&gt;0; adjusting
  05-22 10:05:11.108: D/dalvikvm(104): GC freed 10860 objects / 507696 bytes in 131ms
  </code></pre>