NullPointException Don't Know Why?

Question

Hello guys, please have a look at this code and see if you could help me out. viewItem is populating from a database and the method fillRemindersData(long rowId) is only called from the reminder class. I don't know why i am getting a nullPointerException when calling the viewitems.fillRemindersData()method. if i comment the line, the code works fine and the rowId is correct. what could be the reason? thanks

// this is a reminder class
public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.view_list);
        adapter = new DBAdapter(this);
        viewItems = new ViewItems();
        fillReminder();     
    }

    private void fillReminder() {
        Bundle extra = getIntent().getExtras();
        if(extra != null){
            rowId = extra.getLong(DBAdapter.KEY_ID);


            message = extra.getString(NewItem.Test);
        }
        Toast.makeText(this, message + "its ok here" + rowId, Toast.LENGTH_LONG).show();
        viewItems.fillRemindersData(rowId); // having a null pointer exception here.
}

And important part of the viewItems class is:

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.view_list);
        adapter = new DBAdapter(this);
        adapter.open();
        fillData();
        list = (ListView)findViewById(android.R.id.list);
        list.setOnItemClickListener(this);


    }

 protected void fillData() {

 Cursor c = adapter.retrieveItems(); // method in sqlitedatabase
 startManagingCursor(c);

String[] from = new String[]{DBAdapter.NAME, DBAdapter.START_DATE, DBAdapter.START_TIME};
int[] to = new int[]{R.id.viewNameId, R.id.viewDateId, R.id.viewTimeId};

customCursorAdapter items = new customCursorAdapter(this, R.layout.view_items, c, from, to);
                setListAdapter(items);          

    }

 protected void fillRemindersData(long Id) {
 long row = Id;
 Cursor c = adapter.retrieveRow(row); // method in sqlitedatabase
 startManagingCursor(c);

String[] from = new String[]{DBAdapter.NAME, DBAdapter.START_DATE, DBAdapter.START_TIME};

int[] to = new int[]{R.id.RemindNameId, R.id.remindDateId, R.id.remindTimeId};

customCursorAdapter items = new customCursorAdapter(this, R.layout.remind_viewer, c, from, to);
setListAdapter(items);          

    }

method the logcat is referring to:

public Cursor retrieveRow(long rowId){
String[] resultColumns = new String[] {NAME,START_DATE,START_TIME};
Cursor row = db.query(true,DATABASE_TABLE, resultColumns, KEY_ID +"=" +rowId, null, null, null, null,null);
     if(row != null){
    row.moveToNext();
          return row;
    }
    return row;
     }

Logcat output:

09-22 15:19:00.346: ERROR/AndroidRuntime(808): Uncaught handler: thread main exiting due to uncaught exception
09-22 15:19:00.386: ERROR/AndroidRuntime(808): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.MemoBuzz/com.MemoBuzz.RemindViewer}: java.lang.NullPointerException  


    09-22 15:19:00.386: ERROR/AndroidRuntime(808): Caused by: java.lang.NullPointerException

    09-22 15:19:00.386: ERROR/AndroidRuntime(808):     at com.MemoBuzz.ViewItems.fillRemindersData(ViewItems.java:57)

    09-22 15:19:00.386: ERROR/AndroidRuntime(808):     at com.MemoBuzz.RemindViewer.fillReminder(RemindViewer.java:51)

    09-22 15:19:00.386: ERROR/AndroidRuntime(808):     at com.MemoBuzz.RemindViewer.onCreate(RemindViewer.java:36)

    09-22 15:19:00.386: ERROR/AndroidRuntime(808):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)

    09-22 15:19:00.386: ERROR/AndroidRuntime(808):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2231)

    09-22 15:19:00.386: ERROR/AndroidRuntime(808):     ... 11 more

Answer 1

Are you trying to start an activity with viewItems = new ViewItems();? Is ViewItems an activity class? You have an onCreate() in it. You need to start an activity with an intent, not with new

Answer 2

It looks like onCreate() method of ViewItems is never invoked in your case. Hence adapter is null and you get the exception. Probably you have to put database object out of ViewItems class since right now it looks like an activity or service (and if that is the case invoking constructor on it, like you do, is definitely bad idea).

Answer 3

Looks to me like you didn't add your activity to your manifest.