StringUtils.equals returns false if both arguments are null

[BailinGao]

Describe the bug

StringUtils.equals' javadoc says that passing in two nulls will return true, but the code will always return false because it does a short circuit check for if one of them is null.

Changing it to return true would match the behavior of other StringUtils implementation, such as Apache Commons.

Regression Issue

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Expected Behavior

StringUtils.equals(null, null) == true

Current Behavior

StringUtils.equals(null, null) == false

Reproduction Steps

assertTrue(StringUtils.equals(null, null));

Possible Solution

Change the code to check if both arguments are null

Additional Information/Context

AWS Java SDK version used

2.39.6

JDK version used

8

Operating System and version

Windows 11

[bhoradc]

Hello @BailinGao

Thank you for reporting this issue. You are correct about the inconsitency between the StringUtils.equals() method's Javadoc documentation and its actual implementation in SDK v2.

Javadoc states StringUtils.equals(null, null) = true but the actual implementation always returns false when both parameters are null. This behavior differs from Apache Commons StringUtils, which our implementation is based on.

Can you clarify which specific equivalent class you're referring to in SDK v1 as I couldn't find equals() method in StringUtils - v1.

Kindly note that StringUtils is an internal API - @SdkProtectedApi if you're considering using it directly.

Thank you again for bringing this to our attention, we shall investigate fixing the reported inconsistency in v2.x.

Regards,
Chaitanya

[BailinGao]

After double checking, I was mistaken about it being present and wrong in v1

[debora-ito]

Changing the return to true would be a breaking change, so we fixed the Javadoc to match the current behavior.

@BailinGao Thank you again for pointing this out. Marking to auto close soon, let us know if you have follow-up questions.