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PORuntime error ,When activity start(Activity about listView)
 

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  1. PORuntime error ,When activity start(Activity about listView)
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    <p>This activity is receive value from db.select andthen i put some value to show in the listview model .And i don't know ,how to repair it.If you want more information please tell This is my runtimeError edit when intialize</p> <pre><code>08-21 21:23:36.047: E/AndroidRuntime(408): FATAL EXCEPTION: main 08-21 21:23:36.047: E/AndroidRuntime(408): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sqlite/com.example.sqlite.FriendsListActivity}: java.lang.NullPointerException 08-21 21:23:36.047: E/AndroidRuntime(408): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 08-21 21:23:36.047: E/AndroidRuntime(408): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 08-21 21:23:36.047: E/AndroidRuntime(408): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 08-21 21:23:36.047: E/AndroidRuntime(408): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 08-21 21:23:36.047: E/AndroidRuntime(408): at android.os.Handler.dispatchMessage(Handler.java:99) 08-21 21:23:36.047: E/AndroidRuntime(408): at android.os.Looper.loop(Looper.java:123) 08-21 21:23:36.047: E/AndroidRuntime(408): at android.app.ActivityThread.main(ActivityThread.java:3683) 08-21 21:23:36.047: E/AndroidRuntime(408): at java.lang.reflect.Method.invokeNative(Native Method) 08-21 21:23:36.047: E/AndroidRuntime(408): at java.lang.reflect.Method.invoke(Method.java:507) 08-21 21:23:36.047: E/AndroidRuntime(408): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 08-21 21:23:36.047: E/AndroidRuntime(408): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 08-21 21:23:36.047: E/AndroidRuntime(408): at dalvik.system.NativeStart.main(Native Method) 08-21 21:23:36.047: E/AndroidRuntime(408): Caused by: java.lang.NullPointerException 08-21 21:23:36.047: E/AndroidRuntime(408): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:118) 08-21 21:23:36.047: E/AndroidRuntime(408): at com.example.sqlite.db.FriendsDB.&lt;init&gt;(FriendsDB.java:19) 08-21 21:23:36.047: E/AndroidRuntime(408): at com.example.sqlite.FriendsListActivity.onCreate(FriendsListActivity.java:34) 08-21 21:23:36.047: E/AndroidRuntime(408): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 08-21 21:23:36.047: E/AndroidRuntime(408): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 08-21 21:23:36.047: E/AndroidRuntime(408): ... 11 more </code></pre> <p>This is my Activity </p> <pre><code>package com.example.sqlite; import java.util.ArrayList; import java.util.HashMap; import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import com.example.sqlite.db.FriendsDB; import com.example.sqlite.entry.FriendEntry; public class FriendsListActivity extends Activity { private Context context; private FriendsDB db; private ArrayList&lt;FriendEntry&gt; friends; private TextView hellotext; private ListView hellolistview; ArrayList&lt;HashMap&lt;String, String&gt;&gt; MyArrList = new ArrayList&lt;HashMap&lt;String, String&gt;&gt;(); HashMap&lt;String, String&gt; map; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.friendlist_layout); db = new FriendsDB(context); friends = new ArrayList&lt;FriendEntry&gt;(); showAllList(); } public void showAllList(){ //view matching hellotext = (TextView) findViewById(R.id.hellotext); hellolistview = (ListView) findViewById(R.id.hellolistview); //select data friends = db.selectAll(); if(friends.size()==0){ Toast.makeText(context,"You dont have any friend.",Toast.LENGTH_SHORT).show(); }else{ for (int i = 1;i&lt;=friends.size();i++){ // set value for friends map = new HashMap&lt;String, String&gt;(); map.put("item_nickname", friends.get(i).getNickname()); map.put("item_fname", friends.get(i).getFname()); map.put("item_lname", friends.get(i).getLname()); MyArrList.add(map); Log.i("item_nickname", friends.get(i).getNickname()); Log.i("item_fname", friends.get(i).getFname()); Log.i("item_lname", friends.get(i).getLname()); } //adapter hellolistview.setAdapter(new adapter()); } } private class adapter extends BaseAdapter{ private Holder holder; @Override public int getCount() { // TODO Auto-generated method stub return friends.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub return null; } @Override public long getItemId(int position) { // TODO Auto-generated method stub return 0; } @Override public View getView(int position, View view, ViewGroup parent) { //create if( view == null){ view = LayoutInflater.from(getApplicationContext()).inflate(R.layout.item_layout,null); holder = new Holder(); holder.nickname = (TextView) view.findViewById(R.id.item_nickname); holder.fname = (TextView)view.findViewById(R.id.item_fname); holder.lname = (TextView)view.findViewById(R.id.item_lname); view.setTag(holder); }else{ holder = (Holder) view.getTag(); } //assign data / wait for data holder.nickname.setText(map.get(position)); return view; } private class Holder{ public TextView nickname; public TextView fname; public TextView lname; } } } </code></pre> <p>Thank you</p>
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    1. This table or related slice is empty.
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    1. USThanapoom Na Nakhon
    1. USThanapoom Na Nakhon
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    1. This table or related slice is empty.
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    1. This table or related slice is empty.
    1. COdb is uninitialized hence NPE.
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      1. PORuntime error ,When activity start(Activity about listView)
      1. USTarun
    2. COI don't see `context` being initialized as well. You're using it to show the `Toast`.
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      1. PORuntime error ,When activity start(Activity about listView)
      1. USVikram
 

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