[LANG-1707] Add ArrayUtils.concat methods for concatenating multiple arrays

[ivamly]

Implementation of the LANG-1707 suggestion: added the concat methods to ArrayUtils for convenient concatenation of multiple arrays in a single call.

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[ivamly]

Hi! This is my first contribution to Apache Commons.
I've started by implementing the concat methods for primitive arrays and their corresponding tests.
I would appreciate verification that I'm on the right track. I'm happy to address any feedback and will gladly add the generic T[] method and its tests once the approach is confirmed.

[ivamly]

I'm not entirely sure I understand the question correctly. My implementation was based on the Jira ticket and its comments, where adding these methods was discussed and approved (as I understood it).

Could you please clarify what I might be missing? I'd be happy to adjust the approach if needed.

[garydgregory]

Hello @ivamly

I see this could be useful now...

• Add Javadoc tags @since 3.21.0 on new public and protected methods
• Remove extra blank lines
• Short-circuit the totalLength computations to throw an IllegalArgumentException once the value exceeds SAFE_MAX_ARRAY_LENGTH; you'll likely need to use a long as the running total or use Math.addExact().
• Javadoc: Sentence should end in a period (@param).

[garydgregory]

Hello @ivamly

Are you still working on this?

[ivamly]

Hello @garydgregory! I'll push the changes today.

[ivamly]

@garydgregory done.

[ivamly]

@garydgregory fix build.

[garydgregory]

Hello @ivamly
Are you sure about the length computation? It looks to me like it allows for values > SAFE_MAX_ARRAY_LENGTH but just less than Integer.MAX_VALUE.

[ivamly]

Really, you right. Work on it.