title: Unable to resume activity
body: <p>I am novice and trying to allow my <code>ListView</code> to refresh after my SQLite DB is updated. I am not receiving a compiling error after I revised my <code>onResume()</code> method. I am using a <code>SimpleCursorAdapter</code> to requery but it's not working. The error received was from logcat and is below. Please advise… examples help best.</p>
  
  <p>Logcat:</p>
  
  <pre><code>  02-19 21:31:49.933: E/AndroidRuntime(714): java.lang.RuntimeException: Unable to resume activity {com.loginplus.home/com.loginplus.home.LoginList}: java.lang.NullPointerException
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2444)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2472)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1986)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.app.ActivityThread.access$600(ActivityThread.java:123)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.os.Handler.dispatchMessage(Handler.java:99)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.os.Looper.loop(Looper.java:137)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.app.ActivityThread.main(ActivityThread.java:4424)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at java.lang.reflect.Method.invokeNative(Native Method)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at java.lang.reflect.Method.invoke(Method.java:511)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at dalvik.system.NativeStart.main(Native Method)
    02-19 21:31:49.933: E/AndroidRuntime(714): Caused by: java.lang.NullPointerException
    02-19 21:31:49.933: E/AndroidRuntime(714):    at com.loginplus.home.LoginList.onResume(LoginList.java:101)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1154)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.app.Activity.performResume(Activity.java:4539)
    02-19 21:31:49.933: E/AndroidRuntime(714):    at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2434)
  </code></pre>
  
  <p>Activity:</p>
  
  <pre><code>     public class LoginList extends Activity implements OnClickListener,    OnItemClickListener {
  
  private ListView loginList;
  private Button webLogin;
  
  private ListAdapter loginListAdapter;
  
  private ArrayList&lt;LoginDetails&gt; loginArrayList;
  
  List&lt;String&gt; arrayList = new ArrayList&lt;String&gt;();
  
  @Override 
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      arrayList = populateList();
      loginListAdapter = new ArrayAdapter&lt;String&gt;(this, android.R.layout.simple_list_item_1, populateList());
      setContentView(R.layout.login_listview);
  
  
      loginList = (ListView)
     findViewById(R.id.loginlist);
      loginList.setOnItemClickListener(this);
  
      webLogin = (Button)
     findViewById(R.id.button3);
      webLogin.setOnClickListener(this);
  
  
  }
  
  @Override
  public void onClick (View v) {
      Intent webLoginIntent = new Intent (this, LoginPlusActivity.class);
      startActivity(webLoginIntent);
  
  }
  
  public List&lt;String&gt; populateList (){
  
      List&lt;String&gt; webNameList = new ArrayList&lt;String&gt;();
  
      dataStore openHelperClass = new dataStore (this);
  
      SQLiteDatabase sqliteDatabase = openHelperClass.getReadableDatabase();
  
      Cursor cursor = sqliteDatabase.query(dataStore.TABLE_NAME_INFOTABLE, null, null, null, null, null, dataStore.COLUMN_NAME_SITE, null);
  
      startManagingCursor(cursor);
  
  
      while (cursor.moveToNext()){
      String sName = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_SITE));
      String wUrl = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_ADDRESS));
      String uName = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_USERNAME));
      String pWord = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_PASSWORD));
      String lNotes = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_NOTES));
  
      LoginDetails lpDetails = new LoginDetails();
  
          lpDetails.setsName(sName);
          lpDetails.setwUrl(wUrl);
          lpDetails.setuName(uName);
          lpDetails.setpWord(pWord);
          lpDetails.setlNotes(lNotes);
  
          loginArrayList.add(lpDetails);
          webNameList.add(sName);
  }
  
  sqliteDatabase.close();
  return webNameList;
  }
  
  
  
  @Override
  protected void onResume() {
      super.onResume();
  
      loginArrayList.clear();
  
      arrayList.clear();
  
      arrayList = populateList();
  
      dataStore refreshHelper = new dataStore (this);
      SQLiteDatabase sqliteDatabase = refreshHelper.getWritableDatabase();
      Cursor cursor = sqliteDatabase.query(dataStore.TABLE_NAME_INFOTABLE, null, null, null, null, null, dataStore.COLUMN_NAME_SITE, null);
      String[]columns = new String[] { dataStore.COLUMN_NAME_SITE, dataStore.COLUMN_NAME_ADDRESS, dataStore.COLUMN_NAME_USERNAME, dataStore.COLUMN_NAME_PASSWORD, dataStore.COLUMN_NAME_NOTES };
      int[] to = new int[]{R.id.rusName, R.id.ruwUrl, R.id.ruuName, R.id.rupWord, R.id.ruNotes};
      SimpleCursorAdapter loginListAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, cursor, columns, to);
      loginListAdapter.notifyDataSetChanged();
  
  }
  
  @Override
  public void onItemClick(AdapterView&lt;?&gt; arg0 , View arg1, int arg2, long arg3) {
      Toast.makeText(getApplicationContext(), "Selected ID :" + arg2, Toast.LENGTH_SHORT).show();
  
      Intent updateDeleteLoginInfo = new Intent (this, UpdateDeleteLoginList.class);
  
  
  
      LoginDetails clickedObject = loginArrayList.get(arg2);
  
          Bundle loginBundle = new Bundle();
      loginBundle.putString("clickedWebSite",clickedObject.getsName());
      loginBundle.putString("clickedWebAddress",clickedObject.getwUrl());
      loginBundle.putString("clickedUserName",clickedObject.getuName());
      loginBundle.putString("clickedPassWord",clickedObject.getpWord());
      loginBundle.putString("clickedNotes",clickedObject.getlNotes());
  
      updateDeleteLoginInfo.putExtras(loginBundle);
  
      startActivityForResult(updateDeleteLoginInfo, 0);       
         }    
            }
  </code></pre>
  
  <p>RennoDiniro EditResults:</p>
  
  <p>Logcat:</p>
  
  <pre><code>       02-21 23:40:18.419: E/AndroidRuntime(705): FATAL EXCEPTION: main
         02-21 23:40:18.419: E/AndroidRuntime(705): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.loginplus.home/com.loginplus.home.LoginList}: java.lang.NullPointerException
         02-21 23:40:18.419: E/AndroidRuntime(705):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at android.app.ActivityThread.access$600(ActivityThread.java:123)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at android.os.Handler.dispatchMessage(Handler.java:99)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at android.os.Looper.loop(Looper.java:137)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at android.app.ActivityThread.main(ActivityThread.java:4424)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at java.lang.reflect.Method.invokeNative(Native Method)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at java.lang.reflect.Method.invoke(Method.java:511)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at dalvik.system.NativeStart.main(Native Method)
         02-21 23:40:18.419: E/AndroidRuntime(705): Caused by: java.lang.NullPointerException
         02-21 23:40:18.419: E/AndroidRuntime(705):   at com.loginplus.home.LoginList.populateList(LoginList.java:88)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at com.loginplus.home.LoginList.onCreate(LoginList.java:37)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at android.app.Activity.performCreate(Activity.java:4465)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
         02-21 23:40:18.419: E/AndroidRuntime(705):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
  </code></pre>
  
  <p>Activity Class:</p>
  
  <pre><code>      public class LoginList extends Activity implements OnClickListener,    OnItemClickListener {
  
        private ListView loginList;
        private Button webLogin;
  
        private ListAdapter loginListAdapter;
  
        private ArrayList&lt;LoginDetails&gt; loginArrayList;
  
        List&lt;String&gt; arrayList = new ArrayList&lt;String&gt;();
  
        @Override 
        public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
  
        loginListAdapter = new ArrayAdapter&lt;String&gt;(this,   android.R.layout.simple_list_item_1, populateList());
        arrayList = populateList(); 
        setContentView(R.layout.login_listview);
  
  
        loginList = (ListView)
        findViewById(R.id.loginlist);
        loginList.setOnItemClickListener(this);
  
        webLogin = (Button)
        findViewById(R.id.button3);
        webLogin.setOnClickListener(this);
        }
  
        @Override
        public void onClick (View v) {
        Intent webLoginIntent = new Intent (this, LoginPlusActivity.class);
        startActivity(webLoginIntent);
        }
  
        public List&lt;String&gt; populateList (){
  
        List&lt;String&gt; webNameList = new ArrayList&lt;String&gt;();
  
        dataStore openHelperClass = new dataStore (this);
  
        SQLiteDatabase sqliteDatabase = openHelperClass.getReadableDatabase();
  
        Cursor cursor = sqliteDatabase.query(dataStore.TABLE_NAME_INFOTABLE, null, null, null, null, null, dataStore.COLUMN_NAME_SITE, null);
  
        startManagingCursor(cursor);
  
  
        while (cursor.moveToNext()){
        String sName = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_SITE));
        String wUrl = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_ADDRESS));
        String uName = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_USERNAME));
        String pWord = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_PASSWORD));
        String lNotes = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_NOTES));
  
      LoginDetails lpDetails = new LoginDetails();
  
     lpDetails.setsName(sName);
     lpDetails.setwUrl(wUrl);
     lpDetails.setuName(uName);
     lpDetails.setpWord(pWord);
     lpDetails.setlNotes(lNotes);
  
     loginArrayList.add(lpDetails);
     webNameList.add(sName);
     }
  
     sqliteDatabase.close();
     return webNameList;
      }
  
     @Override
     protected void onResume() {
      super.onResume();
  
      try{
      loginArrayList = new ArrayList&lt;LoginDetails&gt;();
      arrayList = new ArrayList&lt;String&gt;();
      loginArrayList.clear();
      arrayList.clear();
  
      arrayList = populateList();
  
      dataStore refreshHelper = new dataStore (this);
      SQLiteDatabase sqliteDatabase = refreshHelper.getWritableDatabase();
      Cursor cursor = sqliteDatabase.query(dataStore.TABLE_NAME_INFOTABLE, null, null, null, null, null, dataStore.COLUMN_NAME_SITE, null);
      String[]columns = new String[] { dataStore.COLUMN_NAME_SITE, dataStore.COLUMN_NAME_ADDRESS, dataStore.COLUMN_NAME_USERNAME, dataStore.COLUMN_NAME_PASSWORD, dataStore.COLUMN_NAME_NOTES };
       int[] to = new int[]{R.id.rusName, R.id.ruwUrl, R.id.ruuName, R.id.rupWord, R.id.ruNotes};
      SimpleCursorAdapter loginListAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, cursor, columns, to);
      loginListAdapter.notifyDataSetChanged();
       }catch(Exception e)
      {
     e.printStackTrace();
       }
      }
      @Override
      public void onItemClick(AdapterView&lt;?&gt; arg0 , View arg1, int arg2, long arg3) {
      Toast.makeText(getApplicationContext(), "Selected ID :" + arg2,    Toast.LENGTH_SHORT).show();
  
      Intent updateDeleteLoginInfo = new Intent (this, UpdateDeleteLoginList.class);
  
  
  
      LoginDetails clickedObject = loginArrayList.get(arg2);
  
      Bundle loginBundle = new Bundle();
      loginBundle.putString("clickedWebSite",clickedObject.getsName());
      loginBundle.putString("clickedWebAddress",clickedObject.getwUrl());
      loginBundle.putString("clickedUserName",clickedObject.getuName());
      loginBundle.putString("clickedPassWord",clickedObject.getpWord());
      loginBundle.putString("clickedNotes",clickedObject.getlNotes());
  
      updateDeleteLoginInfo.putExtras(loginBundle);
  
      startActivityForResult(updateDeleteLoginInfo, 0);   
     }
     }
  </code></pre>