Toolbar code in Android Studio

XML code :

<androidx.appcompat.widget.Toolbar
    android:id="@+id/toolBar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="@color/colorPrimary"

android:theme="@style/ThemeOverlay.AppCompat.Dark" /> 

java code:

Toolbar toolbar = findViewById(toolBar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("Attitude");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);