Assign value of Optional to a variable if present

Question

Hi I am using Java Optional. I saw that the Optional has a method ifPresent.

Instead of doing something like:

Optional<MyObject> object = someMethod();
if(object.isPresent()) {
    String myObjectValue = object.get().getValue();
}

I wanted to know how I can use the Optional.ifPresent() to assign the value to a variable.

I was trying something like:

String myValue = object.ifPresent(getValue());

What do I need the lambda function to be to get the value assigned to that variable?

Answer 1

You could use #orElse or orElseThrow to improve the readbility of your code.

Optional<MyObject> object = someMethod();
String myValue = object.orElse(new MyObject()).getValue();

---

Optional<MyObject> object = someMethod();
String myValue = object.orElseThrow(RuntimeException::new).getValue();

Answer 2

Quite late but I did following:

String myValue = object.map(x->x.getValue()).orElse("");
                           //or null. Whatever you want to return.