Avoid NoSuchElementException with Stream

Question

I have the following Stream:

Stream stream = stream();

T result = stream.filter(t -> {
    double x = getX(t);
    double y = getY(         


        

Answer 1

Stream#findFirst() returns an Optional which exists specifically so that you don't need to operate on null values.

A container object which may or may not contain a non-null value. If a value is present, isPresent() will return true and get() will return the value.

Otherwise, Optional#get() throws a NoSuchElementException.

If a value is present in this Optional, returns the value, otherwise throws NoSuchElementException.

An Optional will never expose its value if it is null.

If you really have to, just check isPresent() and return null yourself.

Stream stream = stream();

Optional result = stream.filter(t -> {
    double x = getX(t);
    double y = getY(t);
    return (x == tx && y == ty);
}).findFirst();

if (result.isPresent()) 
    return result.get();
return null;