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PONull Pointer Exception
 

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    <p>I'm going nuts trying to figure this one out.When I click on my activity it crashes with a NullPointerException.I've tried debugging but I can't get into the activity in question.I've tried removing the Database,still crashed.I tried removing the ListView,still crashed.I tried modifying the database,still crashed.</p> <p>For some odd reason when I removed the button and its onClickListener on "playbutton",I was able to get into the activity and everything in the activity worked.Can someone help me on why this button is making the app crash before the activity and not on the onclick?</p> <pre><code>04-05 23:15:15.886: E/AndroidRuntime(11445): FATAL EXCEPTION: main 04-05 23:15:15.886: E/AndroidRuntime(11445): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.fullfrontalgames.numberfighter/com.fullfrontalgames.numberfighter.PlayAFriend}: java.lang.NullPointerException 04-05 23:15:15.886: E/AndroidRuntime(11445): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2136) 04-05 23:15:15.886: E/AndroidRuntime(11445): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2174) 04-05 23:15:15.886: E/AndroidRuntime(11445): at android.app.ActivityThread.access$700(ActivityThread.java:141) 04-05 23:15:15.886: E/AndroidRuntime(11445): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1267) 04-05 23:15:15.886: E/AndroidRuntime(11445): at android.os.Handler.dispatchMessage(Handler.java:99) 04-05 23:15:15.886: E/AndroidRuntime(11445): at android.os.Looper.loop(Looper.java:137) 04-05 23:15:15.886: E/AndroidRuntime(11445): at android.app.ActivityThread.main(ActivityThread.java:5059) 04-05 23:15:15.886: E/AndroidRuntime(11445): at java.lang.reflect.Method.invokeNative(Native Method) 04-05 23:15:15.886: E/AndroidRuntime(11445): at java.lang.reflect.Method.invoke(Method.java:511) 04-05 23:15:15.886: E/AndroidRuntime(11445): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792) 04-05 23:15:15.886: E/AndroidRuntime(11445): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555) 04-05 23:15:15.886: E/AndroidRuntime(11445): at dalvik.system.NativeStart.main(Native Method) 04-05 23:15:15.886: E/AndroidRuntime(11445): Caused by: java.lang.NullPointerException 04-05 23:15:15.886: E/AndroidRuntime(11445): at com.fullfrontalgames.numberfighter.PlayAFriend.onCreate(PlayAFriend.java:54) 04-05 23:15:15.886: E/AndroidRuntime(11445): at android.app.Activity.performCreate(Activity.java:5058) 04-05 23:15:15.886: E/AndroidRuntime(11445): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079) 04-05 23:15:15.886: E/AndroidRuntime(11445): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2100) </code></pre> <p><strong>Activity</strong></p> <pre><code>package com.fullfrontalgames.numberfighter; import com.fullfrontalgames.numberfighter.DBAdapter; import com.fullfrontalgames.numberfighter.R; import android.app.Activity; import android.content.Intent; import android.database.Cursor; import android.os.Bundle; import android.support.v4.widget.SimpleCursorAdapter; import android.view.View; import android.widget.Button; import android.widget.ListAdapter; import android.widget.ListView; import android.widget.TextView; public class PlayAFriend extends Activity{ DBAdapter DBAdapter; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.playafriend); final DBAdapter db = new DBAdapter(this); DBAdapter = db.open(); ListView FriendLV = (ListView) findViewById(android.R.id.list); Button playbutton = (Button) findViewById(R.id.playbutton); final TextView friend = (TextView) findViewById(R.id.textview_friends); Cursor friendslist = db.GetAllFriends(); String[] from = new String[] {"FRIENDS"}; // your column/columns here int[] to = new int[] {R.id.textview_friends}; @SuppressWarnings("deprecation") ListAdapter cursorAdapter = new SimpleCursorAdapter(this, R.layout.list_items, friendslist, from, to,0); FriendLV.setAdapter(cursorAdapter); playbutton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub String Defender = friend.getText().toString(); db.GetFriend(Defender); startActivity(new Intent ("com.fullfrontalgames.numberfighter.Fightattacker")); db.close(); } }); } } </code></pre> <p>playafriend xml</p> <pre><code> &lt;?xml version="1.0" encoding="utf-8"?&gt; &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@drawable/nfbackground" android:orientation="vertical" &gt; &lt;ImageView android:id="@id/titlebar" android:layout_width="wrap_content" android:layout_height="66dp" android:src="@drawable/nftitlebar" /&gt; &lt;ListView android:id="@android:id/list" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical" &gt; &lt;/ListView&gt; &lt;/LinearLayout&gt; </code></pre> <p>list_items xml </p> <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical" &gt; &lt;FrameLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:padding="5dp" android:background="@drawable/searchimageview" android:orientation="vertical" &gt; &lt;Button android:id="@+id/playbutton" android:layout_width="60dp" android:layout_height="60dp" android:layout_gravity="right" android:background="@drawable/playbutton" /&gt; &lt;TextView android:id="@+id/textview_friends" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textColor="@color/black" android:textStyle="bold" android:textSize="40dp" android:layout_gravity="center" /&gt; &lt;/FrameLayout&gt; &lt;/LinearLayout&gt; </code></pre>
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    1. COPlease add full stacktrace.
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    2. COYou probably shouldn't have these lines DBAdapter DBAdapter; and DBAdapter = db.open(); Instead db.open(); should suffice. Anyhow, either friend or db are null. Please post logcat with error message.
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    3. COPosting your logcat would even better to understand your issue. Also please post your layout file code.
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