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#1 ahmedba   User is offline

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null pointer exception in method boolean.org.json.jsonobject dobackgro

Posted 22 June 2016 - 03:00 PM

I designed app to make order for pizza food restaurant
I show userid,menu id ,address,longtiude,latitude then press on button make order
Error show after I press button and found in async task do in background
It give me fatal exception error
An error occurred while executing doInBackground()
and it show to me two lines have error
AddNewOrder.doInBackground(Summary.java:113)
AddNewOrder.doInBackground(Summary.java:77)
lines shown in code
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean org.json.JSONObject.getBoolean(java.lang.String)' on a null object reference
package com.pizza_final_project_app.pizza_final_project;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.preference.PreferenceManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

public class Summary extends Activity {
SharedPreferences  preferences;
    private ProgressDialog pDialog;
    //JSONParser jsonParser = new JSONParser();
    boolean errorFound;
    TextView textaddress;
    TextView textlongtiude;
    TextView textlatitude;
    TextView text2;
    TextView textuser;
    Button btnorder;
    private static final String TAG_SUCCESS = "success";
    private static final String TAG = Summary.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_summary);
         text2=(TextView)findViewById(R.id.textView3);
        textaddress=(TextView)findViewById(R.id.textaddress);
       textuser=(TextView)findViewById(R.id.textView4);
         textlongtiude=(TextView)findViewById(R.id.textlongtiude);
         textlatitude=(TextView)findViewById(R.id.textlatitude);
        Intent i = getIntent();
        String id = i.getStringExtra("Data4");
        String address = i.getStringExtra("Data8");
        String longtiude = i.getStringExtra("Data9");
        String latitude = i.getStringExtra("Data10");
        text2.setText(id);
        textaddress.setText(address);
        textlongtiude.setText(longtiude);
        textlatitude.setText(latitude);
        preferences= PreferenceManager.getDefaultSharedPreferences(getApplicationContext());

        String email=preferences.getString("email","");
        textuser.setText(email);
        pDialog = new ProgressDialog(this);
        pDialog.setCancelable(false);
        btnorder=(Button)findViewById(R.id.button2);
        btnorder.setonclickListener(new View.onclickListener() {
            @Override
            public void onclick(View v)
            {
               addOrder(textuser.getText().toString().trim(), text2.getText().toString().trim(),
                        textaddress.getText().toString().trim(), textlongtiude.getText().toString().trim(),
                        textlatitude.getText().toString().trim());

            }
        });
        

    }
//line 77
    class AddNewOrder extends AsyncTask<String, String, String> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(Summary.this);
            pDialog.setMessage("Making Order...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }

        protected String doInBackground(String... args) {
            final  JSONParser jsonParser = new JSONParser();
            // Building Parameters
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("userID", args[0]));
            params.add(new BasicNameValuePair("menuID", args[1]));
            params.add(new BasicNameValuePair("address", args[2]));
            params.add(new BasicNameValuePair("longitude", args[3]));
            params.add(new BasicNameValuePair("latitude", args[4]));


            JSONObject jObj = jsonParser.makeHttpRequest(AppConfig.URL_Order,
                    "POST", params);

            try {
//Line 113
                boolean error = jObj.getBoolean("error"); 
                if (!error) {

                    errorFound=false;
                } else {
                    errorFound=true;

                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;
        }
        protected void onPostExecute(String file_url) {
            if (pDialog.isShowing()) {
                pDialog.dismiss();
                if (!errorFound){
                    Toast.makeText(getApplicationContext(), "User successfully registered. Try login now!", Toast.LENGTH_LONG).show();

                    
                    Intent intent = new Intent(
                            Summary.this,
                           FinalResult.class);
                   startActivity(intent);
                    finish();
                    }
                else{
                    Toast.makeText(getApplicationContext(), "An Error occoured!", Toast.LENGTH_LONG).show();

                }
            }
        }

    }
     */
    private void addOrder(final String userID, final String menuID, final String address,
                              final String longitude, final String latitude) {

        new AddNewOrder().execute(userID, menuID, address, longitude, latitude);

    }

}


Class AppConfig
package com.pizza_final_project_app.pizza_final_project;

public class AppConfig {
   
   public static String URL_Order = "http://amit-learning.com/myPizza/Api_v2.php?function=addOrder";


json parser
 package com.pizza_final_project_app.pizza_final_project;

import android.util.Log;

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.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;

public class JSONParser {

   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<NameValuePair> 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;
            Log.d("data",url);
            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();
         Log.d("json","data is "+json);

      } catch (Exception e) {
         Log.e("Buffer Error", "Error converting result " + e.toString());
      }
      try {
         jObj = new JSONObject(json);
      } catch (JSONException e) {
         Log.e("JSON Parser", "Error parsing data " + e.toString());
      }

      // return JSON String
      return jObj;

   }
}




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Replies To: null pointer exception in method boolean.org.json.jsonobject dobackgro

#2 ahmedba   User is offline

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Reputation: -1
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Re: null pointer exception in method boolean.org.json.jsonobject dobackgro

Posted 24 June 2016 - 07:02 PM

I get this error End of input at character 0 of
after i run code below as you mention before
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}


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