How to use Optional.map()

Consider the below interfaces:

public interface Vc{
}

public interface Vd< P extends Vc, C extends Vcc<{
...
}

public interface VcResult extends Vc{
}

There exists a method which returns Optional

public Optional<Vc> getData()

Here is the method where I am trying to improve the code:

public VcResult mainMethod(){
  Optional<Vc> vc = getData();
  if(vc.isEmpty){
    return anotherMethod();  
  }
  return (VcResult)vc.get();
}

Please suggest in converting this portion:

if(vc.isEmpty){
      return anotherMethod();  
   }
   return (VcResult)vc.get();

to this:

vc.map()..orElseGet(() -> anotherMethod());

What will be the argument of map in the above statement.

>Solution :

You can use VcResult‘s class object to cast it:

public VcResult mainMethod(){
    return getData().map(VcResult.class::cast).orElseGet(this::anotherMethod);
}