add trimToNull method on GrailsStringUtils

[jamesfredley]

This was based on an objective to remove "commons-lang" or "commons-text" where Grails is only using a small number of methods.

Enables api 'org.apache.commons:commons-lang3:3.17.0' to be removed from grails-database-migration.

https://github.com/search?q=repo%3Agrails%2Fgrails-database-migration%20StringUtils&type=code

[codeconsole]

Thanks, I was going to do this, but I would also like a comment that references commons-lang and the version it was taken from and even a permalink to the public repo.

Although it might not be critical for this method, there is a need to bring some other methods over and it is best they keep in sync with the original repo.

In the end, I want to search for "commons-lang" or "commons-text" and easily find this method. This probably should actually be referenced to commons-text if it was moved there.

The end goal is to get rid of commons-lang3 and commons-text completely.

[jamesfredley]

Ok, make any changes you would like.

This method does the same thing, but the implementation is different, utilizing org.springframework.util.StringUtils.hasLength()

[codeconsole]

ok, thanks, still would be useful. It's too bad commons-text depends on commons-lang3. If the 2 dependencies didn't take up so much disk space, I would support keeping them, but I don't see the few methods that we actually use warranting the amount of disk space.

[jeffscottbrown]

This method does the same thing, but the implementation is different, utilizing org.springframework.util.StringUtils.hasLength()

Do you know if the commons-lang method has test coverage for any surprising cases (don't know what they might be)?

Added comment reference common-lang

[jamesfredley]

Added test coverage based on

https://github.com/apache/commons-lang/blob/c8a43a456fb43d2f272a05f3a947bcb9f1719ae8/src/test/java/org/apache/commons/lang3/StringUtilsTrimStripTest.java#L269-L281