public class MainActivity extends ActionBarActivity {

    Toolbar mActionBarToolbar;

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

        mActionBarToolbar = (Toolbar) findViewById(R.id.toolbar_actionbar);
        mActionBarToolbar.setTitle("My title");
        setSupportActionBar(mActionBarToolbar);
}

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    android:orientation="vertical">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar_actionbar"
        android:background="@null"
        android:layout_width="match_parent"
        android:layout_height="?actionBarSize"
        android:fitsSystemWindows="true" />

</LinearLayout>

<style name="AppTheme" parent="Theme.AppCompat">
    <item name="windowActionBar">false</item>
</style>

<style name="AppTheme" parent="Theme.AppCompat.NoActionBar">
    <item name="windowActionBar">false</item>
</style>

mActionBarToolbar = (Toolbar) findViewById(R.id.toolbar_actionbar);
mActionBarToolbar.setTitle("My title");
setSupportActionBar(mActionBarToolbar);

mActionBarToolbar = (Toolbar) findViewById(R.id.toolbar_actionbar);
setSupportActionBar(mActionBarToolbar);
getSupportActionBar().setTitle("My title");

mActionBarToolbar = (Toolbar) findViewById(R.id.toolbar_actionbar);
mActionBarToolbar.setTitle("");
setSupportActionBar(mActionBarToolbar);

mActionBarToolbar.setTitle(title);

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/confirm_order_mail_layout"
    android:layout_width="match_parent"
    android:layout_height="fill_parent">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/confirm_order_appbar_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/confirm_order_list_collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:expandedTitleMarginEnd="64dp"
            app:expandedTitleMarginStart="48dp"
            app:layout_scrollFlags="scroll|enterAlways">

            <android.support.v7.widget.Toolbar
                android:id="@+id/confirm_order_toolbar_layout"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="?attr/colorPrimary"
                app:layout_scrollFlags="scroll|enterAlways"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light">

            </android.support.v7.widget.Toolbar>
        </android.support.design.widget.CollapsingToolbarLayout>
    </android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/confirm_order_mail_layout"
    android:layout_width="match_parent"
    android:layout_height="fill_parent">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/confirm_order_appbar_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <android.support.v7.widget.Toolbar
            android:id="@+id/confirm_order_toolbar_layout"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|enterAlways"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light">

        </android.support.v7.widget.Toolbar>
    </android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>

mActionBarToolbar = (Toolbar) findViewById(R.id.confirm_order_toolbar_layout);
setSupportActionBar(mActionBarToolbar);
getSupportActionBar().setTitle("My Title");

CollapsingToolbarLayout collapsingToolbarLayout = (CollapsingToolbarLayout) findViewById(R.id.confirm_order_mail_layout);
collapsingToolbarLayout.setTitle("My Title");

<android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:title="some title"
        app:popupTheme="@style/AppTheme.PopupOverlay">

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
    myView = inflater.inflate(R.layout.second_layout, container, false);
    getActivity().setTitle("title");

    return myView;
}

<android.support.v7.widget.Toolbar
 xmlns:app="http://schemas.android.com/apk/res-auto"
 android:id="@+id/my_awesome_toolbar"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:background="?attr/colorPrimary"
 android:minHeight="?attr/actionBarSize"
 app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" >

<TextView
   android:id="@+id/toolbar_title"
   android:layout_width="match_content"
   android:layout_height="wrap_content"
   android:gravity="center"
   android:singleLine="true"
   android:text="Toolbar Title"
   android:textColor="@android:color/white"
   android:textSize="18sp"
   android:textStyle="bold" />

</android.support.v7.widget.Toolbar>

toolbar.setLogo(ContextCompat.getDrawable(context, R.drawable.logo));

Activity activity = this.getActivity();
Toolbar toolbar = (Toolbar) activity.findViewById(R.id.detail_toolbar);
        if (toolbar != null) {
            activity.setTitle("Title");
        }

//toolbar.setTitle("Title"); did not give the same results

((MainActivity) context).getSupportActionBar().setTitle(titles.get(position));

toolbar.post(new Runnable() {
            @Override
            public void run() {
                toolbar.setTitle("My Title");
            }
        });

<android.support.v7.widget.Toolbar
    android:layout_width="match_parent"
    android:layout_height="120dp"
    android:id="@+id/tool_bar"
    android:background="@color/tablayout"
    android:theme="@style/ToolBarStyle"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/app_name"
        android:layout_gravity="center"
        android:id="@+id/toolbar_title"
        android:textSize="18sp"
        android:textColor="@color/white"/>
    </android.support.v7.widget.Toolbar>

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    toolbar = (Toolbar) findViewById(R.id.tool_bar);
    toolbar_text = (TextView)findViewById(R.id.toolbar_title);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setDisplayShowTitleEnabled(false);
    toolbar.setLogo(R.drawable.ic_toolbar);
}

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanc``eState);
    setContentView(R.layout.activity_pizza);
    setTitle(getResources().getText(R.string.title));
}

getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_TITLE);