Java 8 lambda Void argument

Question

Let\'s say I have the following functional interface in Java 8:

interface Action {
   U execute(T t);
}

And for some cases I ne

Answer 1

Add a static method inside your functional interface

package example;

interface Action {
       U execute(T t);
       static  Action invoke(Runnable runnable){
           return (v) -> {
               runnable.run();
                return null;
            };         
       }
    }

public class Lambda {


    public static void main(String[] args) {

        Action a = Action.invoke(() -> System.out.println("Do nothing!"));
        Void t = null;
        a.execute(t);
    }

}

Output

Do nothing!