Call a class method within a map

Question

How would I approach telling the HashMap to store a method call within the same class it's stored in?
My initial approach was to call HashMap like so:
HashMap<String, sysCall> cmdList;
It's used to quickly lookup the given input from the user, and call the appropriate method to complete their command. I figured this was more efficient than a large amount of nested if/else statements. Unless someone has a better solution, I'm all ears!
Thanks in advance!

Answer 1

https://code.sololearn.com/c2NSE514hfQL/?ref=app

Answer 2

You could also use a lambda expression instead of calling a method

Answer 3

That's a clever way of getting a class method, that might be a way. I'll read more in depth on it on the text about using that solution.
Also, yes I could use lambda, but these methods already exist, and it'd be silly for me to create a 2nd identical one.
Thanks for the response