ERROR/AndroidRuntime(335): Caused by: java.lang.NullPointerException

Question

Hi i'm new bee to android. while executing my application I'm getting nullpoint exception error, dont know why it is happening. please any one help me to get rid from this issue. thanks in advance.

This is my logcat:

09-14 12:30:14.027: INFO/System.out(365): Constructor StudentList Adapter...
09-14 12:30:14.027: DEBUG/AndroidRuntime(365): Shutting down VM
09-14 12:30:14.027: WARN/dalvikvm(365): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
09-14 12:30:14.047: ERROR/AndroidRuntime(365): FATAL EXCEPTION: main
09-14 12:30:14.047: ERROR/AndroidRuntime(365): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.UserLogin/com.UserLogin.FindPlaces}: java.lang.NullPointerException
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.app.ActivityThread.startActivityNow(ActivityThread.java:2503)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:651)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.widget.TabHost.setCurrentTab(TabHost.java:323)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:129)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:453)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.view.View.performClick(View.java:2408)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.view.View$PerformClick.run(View.java:8816)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.os.Handler.handleCallback(Handler.java:587)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.os.Handler.dispatchMessage(Handler.java:92)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.os.Looper.loop(Looper.java:123)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.app.ActivityThread.main(ActivityThread.java:4627)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at java.lang.reflect.Method.invokeNative(Native Method)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at java.lang.reflect.Method.invoke(Method.java:521)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at dalvik.system.NativeStart.main(Native Method)
09-14 12:30:14.047: ERROR/AndroidRuntime(365): Caused by: java.lang.NullPointerException
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at com.UserLogin.FindPlaces.displayLocs(FindPlaces.java:35)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at com.UserLogin.FindPlaces.onCreate(FindPlaces.java:30)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
09-14 12:30:14.047: ERROR/AndroidRuntime(365):     ... 18 more
09-14 12:30:14.057: WARN/ActivityManager(58):   Force finishing activity com.UserLogin/.Innerpage
09-14 12:30:14.594: WARN/ActivityManager(58): Activity pause timeout for HistoryRecord{4506eef0 com.UserLogin/.Innerpage}
09-14 12:30:16.347: INFO/Process(365): Sending signal. PID: 365 SIG: 9
09-14 12:30:16.367: INFO/ActivityManager(58): Process com.UserLogin (pid 365) has died.
09-14 12:30:16.367: INFO/WindowManager(58): WIN DEATH: Window{4506a6e0 com.UserLogin/com.UserLogin.Innerpage paused=false}
09-14 12:30:16.367: INFO/WindowManager(58): WIN DEATH: Window{451492d0 com.UserLogin/com.UserLogin.UserLogin paused=false}
09-14 12:30:16.397: INFO/UsageStats(58): Unexpected resume of com.android.launcher while already resumed in com.UserLogin

Java file:

import java.util.ArrayList;

import android.app.ListActivity;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

public class FindPlaces extends ListActivity{

    private SQLiteDatabase DbLoc;
    ListView lv;
    private ArrayList<Fields> results = new ArrayList<Fields>();
    @Override
    public void onCreate(Bundle savedInstance) {
        super.onCreate(savedInstance);
        //setContentView(R.layout.places);
        getallLocs();
        displayLocs();

    }
    private void displayLocs() {
        lv = (ListView)findViewById(R.id.listPlaces);
        lv.setAdapter(new StudentListAdapter(this, R.layout.placeslist, results));

        //lv.setAdapter(new ArrayAdapter<Fields>(this,android.R.layout.simple_list_item_1, results));

    }
    class StudentListAdapter extends ArrayAdapter<Fields>{
        private ArrayList<Fields> locationDetails;
        private Context mContext;

        public StudentListAdapter(Context context,int textViewResourceId, ArrayList<Fields> results) {
            super(context, textViewResourceId, results);
            // TODO Auto-generated constructor stub
            System.out.println("Constructor StudentList Adapter...");
            this.locationDetails = results;
            mContext = context;
        }


        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return results.size();
        }

        @Override
        public Fields getItem(int position) {
            // TODO Auto-generated method stub
            return locationDetails.get(position);
        }
        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return super.getItemId(position);
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            View v = convertView;
            if(v == null){
                LayoutInflater vl = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                v = vl.inflate(R.layout.placeslist, null);
            }
                            Fields o = results.get(position);

            if (o != null) {

                TextView iv = (TextView)v.findViewById(R.id.toptext);
                TextView tv_sNo = (TextView)v.findViewById(R.id.toptext1);
                iv.setText(o.getLocationName());                            
                tv_sNo.setText(o.getLocationImage());   

            }
            DbLoc.close();
            return v;
        }       
    }
    static class ViewHolder
    {
        TextView Locationname;
        ImageView Locationimage;
    }
    private void getallLocs() {
        // TODO Auto-generated method stub
        try {
            DatabaseHelper dbHelper = new DatabaseHelper(
                    this.getApplicationContext());
            DbLoc = dbHelper.getWritableDatabase();
            Cursor c = DbLoc.rawQuery("SELECT " + DatabaseHelper.LocationName+ " , " + DatabaseHelper.LocationImage + " FROM "
                    + DatabaseHelper.LOCATIONTABLE , null);
                            if (c != null) {
                if (c.moveToFirst()) {
                    do {
                        String LocationName= c.getString(c.getColumnIndex("LocationName"));
                        String Mobile = c.getString(c
                                .getColumnIndex("LocationImage"));
                        Fields p = new Fields(LocationName, Mobile);
                        results.add(p);

                    } while (c.moveToNext());
                }
            }
        } catch (SQLiteException se) {
            Log.e(getClass().getSimpleName(),
            "Could not create or Open the database");
        } 
        finally { if (DbLoc != null) DbLoc.execSQL("DELETE FROM " +
                DatabaseHelper.FRIENDTABLE); DbLoc.execSQL("DELETE FROM " +
                        DatabaseHelper.LOCATIONTABLE);  
                DbLoc.execSQL("DROP TABLE IF EXISTS tablename"+ DatabaseHelper.FRIENDTABLE);
                DbLoc.execSQL("DROP TABLE IF EXISTS tablename"+ DatabaseHelper.LOCATIONTABLE);
                DbLoc.close();
        }
    }
}

Places.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:padding="6dip">
    <ListView android:id="@+id/listPlaces" android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

Placeslist.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="wrap_content">
    <TextView android:id="@+id/toptext" android:layout_width="fill_parent"
        android:layout_height="0dip" android:layout_weight="1"
        android:gravity="center_vertical" />
    <TextView android:id="@+id/toptext1" android:layout_width="fill_parent"
        android:layout_height="0dip" android:layout_weight="1"
        android:gravity="center_vertical" />
</LinearLayout>

Mohammed Azharuddin Shaikh · Accepted Answer · 2011-09-14T09:17:37.720

4

uncomment this line

setContentView(R.layout.places);

EDITED:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:padding="6dip">
    <ListView android:id="@android:id/list" android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

replace this with your file(Places.xml)

UPDATED

 public void onCreate(Bundle savedInstance) {
        super.onCreate(savedInstance);
        //setContentView(R.layout.places);
        getallLocs();
        setListAdapter(new ArrayAdapter<Fields>(this,android.R.layout.simple_list_item_1, results));
//        displayLocs();

    }
    private void displayLocs() {
        lv = (ListView)findViewById(R.id.listPlaces);
        lv.setAdapter(new StudentListAdapter(this, R.layout.placeslist, results));

        //lv.setAdapter(new ArrayAdapter<Fields>(this,android.R.layout.simple_list_item_1, results));

    }

edited Sep 14 '11 at 09:17

answered Sep 14 '11 at 07:20

Mohammed Azharuddin Shaikh

41,633
14
96
115

after uncommenting getting 09-14 12:49:50.902: ERROR/AndroidRuntime(395): Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list' in logcat – atluriajith Sep 14 '11 at 07:27
after replacing places.xml file lv = (ListView)findViewById(R.id.listPlaces); this will be error. – atluriajith Sep 14 '11 at 08:32
yes. i've removed that line now getting 09-14 14:13:54.206: ERROR/AndroidRuntime(479): Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list' – atluriajith Sep 14 '11 at 08:48
yes. i've replaced with your edited xml file, and now i've build my project once and checked now getting this error :::: 09-14 14:28:09.247: ERROR/AndroidRuntime(539): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.UserLogin/com.UserLogin.FindPlaces}: java.lang.NullPointerException 09-14 14:28:09.247: ERROR/AndroidRuntime(539): Caused by: java.lang.NullPointerException – atluriajith Sep 14 '11 at 09:04
comment displayLocs(); method – Mohammed Azharuddin Shaikh Sep 14 '11 at 09:08
If i comment displayLocs(); method then i'll not get display the locations. – atluriajith Sep 14 '11 at 09:10
Thanks for your posts. It's really got my solution.. and one more how can i display an image with image url. – atluriajith Sep 14 '11 at 09:23
see this http://stackoverflow.com/questions/6815355/how-to-store-image-retreived-from-url-in-a-sqlite-database/6815819#6815819 and finally http://meta.stackexchange.com/questions/5234/how-does-accepting-an-answer-work – Mohammed Azharuddin Shaikh Sep 14 '11 at 09:25
@hotveryspicy with your editecode layoutinflating is not happening.. its just displaying in default simple_list_item_1.. – atluriajith Sep 14 '11 at 09:48

Lukas Knuth · Answer 2 · 2011-09-14T09:16:37.813

4

You can't use findViewById() if you haven't set a content-view for the activity. So your lv will be null.

You're using a ListActivity. If you want to add your own style to it, the ListView in your layout needs the id android:list:

<ListView android:id="@android:id/list"
  ...
/>

As illustrated here.

If you use a ListActivity, you don't use findViewById() to get the ListView, you can use the getListView()-method.

edited Sep 14 '11 at 09:16

answered Sep 14 '11 at 07:21

Lukas Knuth

25,449
15
83
111

after replacing places.xml file lv = (ListView)findViewById(R.id.listPlaces); this will be error. – atluriajith Sep 14 '11 at 08:42
If you use a `ListActivity`, and you want to customize it, the `ListView` needs the above id. You can access it in Java by using the [`getListView()`-method](http://developer.android.com/reference/android/app/ListActivity.html#getListView()) – Lukas Knuth Sep 14 '11 at 09:14
I've commented this above line and i'm just calling adapter---- lv.setAdapter(new StudentListAdapter(this, R.layout.placeslist, results));------ now i'm getting --- 14 14:28:09.247: ERROR/AndroidRuntime(539): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.UserLogin/com.UserLogin.FindPlaces}: java.lang.NullPointerException 09-14 14:28:09.247: ERROR/AndroidRuntime(539): Caused by: java.lang.NullPointerException – atluriajith Sep 14 '11 at 09:20
Thanks for your posts. It's really got my solution.. and one more how can i display an image with image url. – atluriajith Sep 14 '11 at 09:23
with @hotveryspicy help i can able to get values to listview. But i need those values in custom list view. I want to display those values by inflating layout. can you please help me. – atluriajith Sep 14 '11 at 10:15
You might want to create a new question for that... and use google. – Lukas Knuth Sep 14 '11 at 10:22

ERROR/AndroidRuntime(335): Caused by: java.lang.NullPointerException

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