Use java time classes inside Personnummer

[ullenius]

Type of change

• New feature
• Bug fix
• Security patch
• Documentation update

Description

Replace use of String with Java's time classes Year and Month.

getFullYear() now returns a Year object.

Related issue

Motivation

• Better OOP
• Strong typing
• Increased performance. Strings are slow and allocate lots of memory.

Checklist

• I have read the CONTRIBUTING document.
• I have read and accepted the Code of conduct
• Tests passes.
• Style lints passes.
• Documentation of new public methods exists.

[ullenius]

The property name year may cause confusion. Perhaps decade is a better name?

String getDecade()
Year getYear()

[Johannestegner]

Hi @ullenius,
Thank you for the pull request!

I agree with the structure change and think your reasoning is correct, but I must take it up with the team to make sure we don't wander off too much from the core interface.
Will get back to you asap! :)

[ullenius]

@Johannestegner
No worries. I was thinking of changing the getMonth()-method to return a Month object.

But I'd rather keep the PR small as this is a breaking change.

Storing the day and month inside a MonthDay object inside the class is also a possibility:

private final MonthDay monthDay;

public int getDay() { // breaks interface but is super fast
	return monthDay.getDay();
}

public Month getMonth() {
	return monthDay.getMonth();
}