Question

So, I have two classes, one that adds tasks and one that adds categories. When adding a task you can associate that task with a category which is populated using a dropdown and the database enforces foreign keys by using triggers. I have got the application adding tasks correctly but I’m catching a null pointer exception with my add category class, and I’m having trouble pinning down where it is – I’ve looked in logcat but it hasn’t been particularly helpful.

The class is as follows:

public class AddCategory extends Activity {
    EditText txtCatName;
    DatabaseHelper dbHelper;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.addcategory);
        txtCatName = (EditText) findViewById(R.id.txtCatName);
    }

    public void btnAddCat_Click(View view) {
        boolean ok = true;
        try {
            String name = txtCatName.getText().toString();
            DatabaseMethods cat = new DatabaseMethods(name);

            dbHelper.AddCategory(cat);

        } catch (Exception ex) {
            ok = false;
            CatchError(ex.toString());
        } finally {
            if (ok) {
                // NotifyEmpAdded();
                Toasts.ShowTaskAddedAlert(this);
            }
        }
    }

    void CatchError(String Exception) {
        Dialog diag = new Dialog(this);
        diag.setTitle("Add new Category");
        TextView txt = new TextView(this);
        txt.setText(Exception);
        diag.setContentView(txt);
        diag.show();
    }

    void NotifyCatAdded() {
        Dialog diag = new Dialog(this);
        diag.setTitle(this.getString(R.string.add_category));
        TextView txt = new TextView(this);
        txt.setText(this.getString(R.string.category_added));
        diag.setContentView(txt);
        diag.show();
        try {
            diag.wait(1000);
        } catch (InterruptedException e) {
            CatchError(e.toString());
        }
        diag.notify();
        diag.dismiss();
    }

} 

If you need any more code then please just ask. Any help is much appreciated. Always helps to get a couple of more pairs of eyes on code to find errors :).

Answer 1

I don’t see where dbHelper is being initialized, so I would suspect it would be returning as null. Put a breakpoint at dbHelper.AddCategory(cat); and see if dbHelper is null.