getActionBar() returns null

android android-3.0-honeycomb android-actionbar

Can use getSupportActionBar() instead of getActionBar() method.

android android-3.0-honeycomb android-actionbar

import android.support.v7.app.ActionBarActivity;public class MainActivity extends ActionBarActivity {

The class ActionBarActivity now is deprecated:

import android.support.v7.app.ActionBarActivity;

I recommend to use:

import android.support.v7.app.AppCompatActivity

android android-3.0-honeycomb android-actionbar

if you are using android.support.v7.app.AppCompatActivity
public class HomeActivity extends AppCompatActivity {

Then you should be using android.support.v7.app.ActionBar

  ActionBar ab = getSupportActionBar();

If you are using android.support.v4.app.FragmentActivity
public class HomeActivity extends FragmentActivity {

then you should be using android.app.ActionBar

    ActionBar ab = getActionBar();

If you are using android.support.v7.app.ActionBarActivity
public class HomeActivity extends ActionBarActivity {

you should be using android.support.v7.app.ActionBar

   ActionBar ab = getSupportActionBar();