CODEWITHSUNDEEP
android
Arya Lakshmi
Arya Lakshmi

Reputation: 1

android:Null pointer Exception

I have been developing an app and fair prediction is a part of it.. it contains a webpart too.. but i cant login into that part.. the app is terminating by that time.. the login page is linked to a jsp page and inturn to a mysql database.. i m posting the code here.. pls help me.. thanks in advance..

Tlogin.java

package com.example.tracemeendpointsjson;

import java.util.ArrayList;

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;

import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class TLogin extends Activity  {

    EditText uname,pwd;
    Button log,signup;
    String response="";
    NameValuePair v;
    String LoginID,LoginPassword;
    HttpRequestClass mynetworkclass;
    ArrayList<NameValuePair> namevaluepair;

    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.tlogin);
        uname=(EditText) findViewById(R.id.uname);
        pwd=(EditText) findViewById(R.id.pwd);
        log=(Button) findViewById(R.id.login);
        signup=(Button) findViewById(R.id.bSignup);
        log.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                LoginID=uname.getText().toString();
                LoginPassword=pwd.getText().toString();
                //CommonClassForLogin q=(CommonClassForLogin) getApplication();
                //q.myUID=LoginID;

                String url="http://"+details.ip+"taxinew/mobile/login.jsp";

            new AsyncTaskLogin().execute(url,LoginID,LoginPassword);


            }
        });

    }
    public class AsyncTaskLogin extends AsyncTask<String, Integer, String>  
    {

        @Override
        protected String doInBackground(String... params) {
            // TODO Auto-generated method stub
            mynetworkclass=new HttpRequestClass();
            namevaluepair=new ArrayList<NameValuePair>();
            namevaluepair.add(new BasicNameValuePair("username",params[1]));
            namevaluepair.add(new BasicNameValuePair("password",params[2]));

            try {
                String result=mynetworkclass.getinformation(params[0],namevaluepair);
                Log.d("dsfwewerte", result);
                result=result.replaceAll("\\r|\\n", "");
            return result;

        } catch (Exception e) {
            e.printStackTrace();
        }
            return null;
        }

        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            //Log.d("222222222", result);

            if(result.equals("0"))
            {
                Toast.makeText(getApplicationContext(),"Welcomes You", Toast.LENGTH_SHORT).show();
                Intent in=new Intent(getApplicationContext(), Trip.class);
                startActivity(in);

                //Log.d("11111111111", result);
            }
            else
            {
                Toast.makeText(getApplicationContext(),"Wrong Entry", Toast.LENGTH_SHORT).show();
                Intent in1=new Intent(getApplicationContext(), Home.class);
                startActivity(in1);

                //Log.d("0000000000", result);

            }




        }



    }

}

the HttprequestClass is as follows

package com.example.tracemeendpointsjson;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
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.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.util.Log;
import android.widget.Toast;

public class HttpRequestClass {
    HttpClient httpclient;
    public String getinformation(String url,ArrayList<NameValuePair> namevaluepair) throws ParseException, IOException
    {
        httpclient=new DefaultHttpClient();
        HttpPost request=new HttpPost(url);
        request.setEntity(new UrlEncodedFormEntity(namevaluepair));
        try
        {
            HttpResponse respnse=httpclient.execute(request);
            int status=respnse.getStatusLine().getStatusCode();
            if(status==200)
            {
                HttpEntity e=respnse.getEntity();
                String data=EntityUtils.toString(e);
                return data;
            }
        }
        catch(ClientProtocolException e)
        {
            e.printStackTrace();
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }


        return null;

    }


    public String getsingleinformation(String url) throws ParseException, IOException
    {
        httpclient=new DefaultHttpClient();
        HttpPost request=new HttpPost(url);
        try
        {
            HttpResponse respnse=httpclient.execute(request);
            int status=respnse.getStatusLine().getStatusCode();
            if(status==200)
            {
                HttpEntity e=respnse.getEntity();
                String data=EntityUtils.toString(e);
                return data;
            }                               
        }
        catch(ClientProtocolException e)
        {
            e.printStackTrace();
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }


        return null;

    }
}

the manifest file is as listed below:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.tracemeendpointsjson"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="7"
        android:targetSdkVersion="15" />
<uses-permission android:name="android.permission.INTERNET"/>
 <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.SEND_SMS"/>
    <uses-permission android:name="android.permission.WAKE_LOCK"/>

    <application
        android:icon="@drawable/traffic"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
           <uses-library android:name="com.google.android.maps"/>
        <activity
            android:name="com.example.tracemeendpointsjson.Home"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".MainActivity"></activity>
         <activity
            android:name=".UploadDetails"></activity>
        <activity
            android:name=".CurrentLocation"></activity>
        <activity
            android:name=".GmailLogin"></activity>
         <activity
            android:name=".MailReceivers"></activity>
         <activity
            android:name=".ShowWeather"></activity>
         <activity
            android:name=".DisplayWeather"></activity>
          <activity
            android:name=".Trip"></activity>
           <activity
            android:name=".ShowRoute"></activity>
           <activity
            android:name=".Parking"></activity>
            <activity
            android:name=".Estfare"></activity>
             <activity
            android:name=".GetFare"></activity>
           <activity 
               android:name=".TLogin">
           </activity>
           <activity
            android:name=".ParkingPlaceShow"></activity>

        <service android:name=".ServiceClass" >
        </service>

      <!-- <service android:name=".GPSTracker"></service> -->  

    </application>

</manifest>

the logcat output:

03-20 09:51:30.866: E/AndroidRuntime(476): FATAL EXCEPTION: main
03-20 09:51:30.866: E/AndroidRuntime(476): java.lang.NullPointerException
03-20 09:51:30.866: E/AndroidRuntime(476):  at com.example.tracemeendpointsjson.TLogin$AsyncTaskLogin.onPostExecute(TLogin.java:85)
03-20 09:51:30.866: E/AndroidRuntime(476):  at com.example.tracemeendpointsjson.TLogin$AsyncTaskLogin.onPostExecute(TLogin.java:1)
03-20 09:51:30.866: E/AndroidRuntime(476):  at android.os.AsyncTask.finish(AsyncTask.java:417)
03-20 09:51:30.866: E/AndroidRuntime(476):  at android.os.AsyncTask.access$300(AsyncTask.java:127)
03-20 09:51:30.866: E/AndroidRuntime(476):  at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429)
03-20 09:51:30.866: E/AndroidRuntime(476):  at android.os.Handler.dispatchMessage(Handler.java:99)
03-20 09:51:30.866: E/AndroidRuntime(476):  at android.os.Looper.loop(Looper.java:130)
03-20 09:51:30.866: E/AndroidRuntime(476):  at android.app.ActivityThread.main(ActivityThread.java:3683)
03-20 09:51:30.866: E/AndroidRuntime(476):  at java.lang.reflect.Method.invokeNative(Native Method)
03-20 09:51:30.866: E/AndroidRuntime(476):  at java.lang.reflect.Method.invoke(Method.java:507)
03-20 09:51:30.866: E/AndroidRuntime(476):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
03-20 09:51:30.866: E/AndroidRuntime(476):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
03-20 09:51:30.866: E/AndroidRuntime(476):  at dalvik.system.NativeStart.main(Native Method)
03-20 09:51:30.896: W/ActivityManager(83):   Force finishing activity com.example.tracemeendpointsjson/.TLogin
03-20 09:51:31.428: W/ActivityManager(83): Activity pause timeout for HistoryRecord{40803618 com.example.tracemeendpointsjson/.TLogin}

03-20 09:51:33.555: E/InputDispatcher(83): channel '40800e70 com.example.tracemeendpointsjson/com.example.tracemeendpointsjson.Home (server)' ~ Consumer closed input channel or an error occurred.  events=0x8
03-20 
09:51:33.555: E/InputDispatcher(83): channel '40800e70 com.example.tracemeendpointsjson/com.example.tracemeendpointsjson.Home (server)' ~ Channel is unrecoverably broken and will be disposed!

Login.jsp is as follows:

<%-- 
    Document   : login
--%>
<%@page import="javax.swing.JOptionPane,DB.DbCon"%>
<%@page import="org.json.JSONObject" %>
<%@page import="org.json.JSONArray" %>
<%@page import="java.sql.ResultSet"%>


<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%
String username=request.getParameter("username");
String password=request.getParameter("password");

JSONObject jo= new JSONObject();
//JSONArray ja=new JSONArray();
String query="select * from Userdetails where name='"+username+"' and pwd='"+password+"' ";

DbCon o=new DbCon();
ResultSet rs=o.selects(query);
         if(rs.next()){
             jo.accumulate("0", true);

         }

       else
                     {

        jo.accumulate("1", false);
               }

     out.print(jo);


%>

Upvotes: 0

Views: 102

Answers (4)

Ankitkumar Makwana
Ankitkumar Makwana

Reputation: 3485

You can Return result "with No data" with default and match it, you can also debug and check your Response what you get

Upvotes: 0

GrIsHu
GrIsHu

Reputation: 23638

Just try to return the result in your doInBackground method at the end besides null. At the end of that method you are returning null that is why its throwing the nullpointer excepection.

Or you need to check for the null value of the result in your onPostExecute method to prevent the exception to be thrown.

 @Override
    protected String doInBackground(String... params) {
        // TODO Auto-generated method stub
        mynetworkclass=new HttpRequestClass();
        namevaluepair=new ArrayList<NameValuePair>();
        namevaluepair.add(new BasicNameValuePair("username",params[1]));
        namevaluepair.add(new BasicNameValuePair("password",params[2]));
        try {
            String result=mynetworkclass.getinformation(params[0],namevaluepair);
            Log.d("dsfwewerte", result);
            result=result.replaceAll("\\r|\\n", "");
        return result;
    } catch (Exception e) {
        e.printStackTrace();
    }
        return result;       <----- Check this line.
    }
    @Override
    protected void onPostExecute(String result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);
      //Check for the result is null or not.
       if(result != null)
       {
             if(result.equals("0"))
             {}
        }
   }

Upvotes: 0

Sulabh Gajjar
Sulabh Gajjar

Reputation: 501

Try these code.. I think these is the problem. 

protected String doInBackground(String... params) {
        // TODO Auto-generated method stub
        String result;
        mynetworkclass=new HttpRequestClass();
        namevaluepair=new ArrayList<NameValuePair>();
        namevaluepair.add(new BasicNameValuePair("username",params[1]));
        namevaluepair.add(new BasicNameValuePair("password",params[2]));

        try {
            result=mynetworkclass.getinformation(params[0],namevaluepair);
            Log.d("dsfwewerte", result);
            result=result.replaceAll("\\r|\\n", "");
        return result;

    } catch (Exception e) {
        e.printStackTrace();
    }
        return result;
}

Upvotes: 2

iTech
iTech

Reputation: 18430

Your result is null, a simple change to your if-condition could solve this problem

if("0".equals(result))

Upvotes: 1

Related Questions