Spring Use Integer.parseInt without substring method

As Spring Framework 6 uses JDK17 for its baseline, parseInt method can be used without using substring method. - use parseInt(CharSequence s, int beginIndex, int endIndex, int radix) - JDK 9

I think this modification can prevent to create unnecessary string object.

Comment From: pivotal-cla

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Comment From: pivotal-cla

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Comment From: poutsma

Merged in 804b343

Thank you for submitting a PR!