Comparable Arns - Githubissues

Describe the feature

It'd be nice if Arn implemented Comparable<Arn>.

This would make Arns usable in sorted collection types, etc.

Is your Feature Request related to a problem?

Not really.

We can use HashMap<Arn, ...> instead of TreeMap<Arn, ...>, etc.
We can sort Arns by converting to strings, sorting, then converting back to Arns.

So this would just make Arns more flexible.

Proposed Solution

Here is a straightforward implementation:

public static final Comparator<Arn> COMPARATOR =
    Comparator.comparing(Arn::toString);

@Override
public int compareTo(Arn rhs) {
    return COMPARATOR.compare(this, rhs);
}

Here is a more elaborate one, which may be more efficient by avoiding the String construction:

public static final Comparator<Arn> COMPARATOR =
    Comparator.comparing(Arn::partition)
              .thenComparing(Arn::service)
              .thenComparing(x -> x.region, Comparator.nullsLast(Comparator.naturalOrder()))
              .thenComparing(x -> x.accountId, Comparator.nullsLast(Comparator.naturalOrder()))
              .thenComparing(Arn::resourceAsString);

@Override
public int compareTo(Arn rhs) {
    return COMPARATOR.compare(this, rhs);
}

Describe alternatives you've considered

No response

Acknowledge

[X] I may be able to implement this feature request

AWS Java SDK version used

aws-sdk-java-v2 c0eb030fceaa9ccb64ad8acd74445f4e5ee3a547

JDK version used

openjdk version "1.8.0_312"

Operating System and version

MacOS Big Sur Version 11.6.2 (20G314)

aws / aws-sdk-java-v2

Comparable Arns #2955