Prevent a class from being extended

 

  • A class cannot be used as a superclass if it contains the final keyword in its class definition: 

    
/* ======================================
   This class cannot be extended
   ====================================== */
public final class myClass 
{
   // Data fields, constructors, and methods omitted
}

Prevent a inherited method from being overridden

 

  • You can disallow a method to be overridden by the inheritance mechanism by using the final keyword: 

    public  class myClass 
{
    ....

    /* ======================================
       This method cannot be overridden
       ====================================== */
    public final void method1()
    {
        // Do something
    }

    ....
}