Spring Add conversion support for Pattern/Regex

Comment From: sbrannen

@valfirst, can you please provide some background on the rationale for your proposal?

Do you have a particular use case that requires this support?

In addition, have you seen org.springframework.beans.propertyeditors.PatternEditor?

Comment From: valfirst

@sbrannen thank you for quick response! We use conversion service to perform type conversion: https://github.com/vividus-framework/vividus/blob/master/vividus/src/main/resources/org/vividus/spring-configuration.xml#L51. At some point we faced with necessity to convert String value from the property to Optional<Pattern> type. One of the proposed solutions was to re-use all property editors: https://github.com/vividus-framework/vividus/pull/185/commits/cbe84d8234b0d2055dcd0c9c2f2ae6f7791900dc. For me this solution looks awkward. I haven't found existing converter for Pattern type in Spring, so I've implemented own one and add it to our conversion service. It works as expected. I think the converter looks generic enough and could be useful for other users, so I've decided to create this PR.

Comment From: sbrannen

Thanks for providing the feedback on your use case.

We'll take that into consideration.

Comment From: valfirst

@sbrannen could you please review the changes when you have a chance? thanks

Comment From: sokomishalov

I think it makes sense to provide the same converter from String to kotlin.text.Regex if kotlin is present in the classpath due to closing the similar PR in the boot repository. https://github.com/spring-projects/spring-boot/pull/23706

Comment From: ikalinin1

@sbrannen could you please take a look at this PR

Comment From: snicoll

Thanks @valfirst, I polished the proposal by adding support for Kotlin's Regex as well.