StringToLocaleConverter should allow BCP 47 values [SPR-16188]

[spring-projects-issues]

adrian opened SPR-16188 and commented

I'm using Spring Boot to setup locale in spring mvc.

I'm trying to use BCP 47 for spring.mvc.locale value, but I end up with a

Property: spring.mvc.locale
Value: en-US
Reason: Failed to convert property value of type 'java.lang.String' to required type 'java.util.Locale' for property 'locale'; nested exception is org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [java.lang.String] to type [java.util.Locale]

StringToLocaleConverter (relies on StringUtils.parseLocaleString) relies on _ delimiters, which is not BCP 47.

Could StringToLocaleConverter be improved to handle BCP 47 (or otherwise try both formats ?)

For BCP-47, it would correspond to calling
https://docs.oracle.com/javase/7/docs/api/java/util/Locale.html#forLanguageTag(java.lang.String)

wdyt ?

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Affects: 4.3.10

Issue Links:

• BCP 47 compatible Locale support [SPR-13274] #17865 BCP 47 compatible Locale support
• Revise StringUtils.parseLocale(String) for proper handling of corner cases [SPR-16651] #21192 Revise StringUtils.parseLocale(String) for proper handling of corner cases
• CookieLocaleResolver is not RFC6265 compliant when setting a locale and time zone [SPR-16700] #21241 CookieLocaleResolver is not RFC6265 compliant when setting a locale and time zone
• ScheduledAnnotationBeanPostProcessor does not support Duration syntax [SPR-15455] #20016 ScheduledAnnotationBeanPostProcessor does not support Duration syntax

Referenced from: commits ef3f93e

[spring-projects-issues]

Juergen Hoeller commented

Good point! StringToLocaleConverter leniently supports both variants now, through a new StringUtils.parseLocale variant which adapts to both BCP 47 and the traditional Locale.toString() format.

[spring-projects-issues]

adrian commented

Great ! Thanks very much Juergen