Main Activity Class

MainActivity.java

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(@Nullable final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar_main);
        toolbar.setTitle(getResources().getString(R.string.app_name));
        toolbar.setPadding(0, getStatusBarHeight(), 0, 0);
        setSupportActionBar(toolbar);
    }

    private int getStatusBarHeight() {
        final int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
        return resourceId > 0 ? getResources().getDimensionPixelSize(resourceId) : 0;
    }
}