Add conversion support for java.time.Duration [SPR-13579]

[spring-projects-issues]

Joseph Walton opened SPR-13579 and commented

Java 8's java.time.Duration is a good choice for defining durations of time, and arguably better than using a long with a property name to specify the units.

It would be good to support conversion from a String to make it easier to use beans that use this in their API.

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Issue Links:

• Add JSR 310 Period and Duration Converters [SPR-13721] #18294 Add JSR 310 Period and Duration Converters ("duplicates")
• Add conversion support for Joda Duration and Period [SPR-6706] #11372 Add conversion support for Joda Duration and Period
• Conversion support for java.time.YearMonth (as well as MonthDay) [SPR-13518] #18095 Conversion support for java.time.YearMonth (as well as MonthDay)

[spring-projects-issues]

Joseph Walton commented

This is similar to #11372, but only for java.time, rather than JODA.

[spring-projects-issues]

Joseph Walton commented

PR: SPR-13579: Support conversion from Strings to Java 8 Durations..

[spring-projects-issues]

Piotr Findeisen commented

Hi,

I, too, started to use Duration for configuration properties rather than things like "someTimoutMillis". I realized Spring does not offer out-of-the-box conversion from String to Duration, at least not when using context:property-override, so a created a PR #1231 -- all this before finding this issue.

This issue is closed, but I tested Spring master branch and couldn't get expected behavior (no conversion was found) before applying my patch. I see Joseph Walton adds completely different class than my PR, so I guess this isn't equivalent, Maybe I understand "conversion" differently than this issue. Juergen Hoeller could you please have a look?

[spring-projects-issues]

Juergen Hoeller commented

Piotr Findeisen, we're only supporting Duration and Period in org.springframework.format's JSR-310 package at this point, along with the general date-time types, analogous to Joda-Time. The ISO text representations for date-time types are arguably rather serialization-oriented and not really intuitive for user-driven configuration purposes, which is why we haven't added them to the core property editors.

If you'd like to enable such ISO formatting rules for configuration purposes, set up your application context with a DefaultFormattingConversionService out of the box, e.g. a bean with name "conversionService" which will get picked up for bean property values as well then.

[spring-projects-issues]

Piotr Findeisen commented

Juergen Hoeller, thanks for your response. I didn't know about formatters and that they can be plugged as property editors. Thanks for explaining this to me.

The ISO text representations for date-time types are arguably rather serialization-oriented and not really intuitive for user-driven configuration purposes

I couldn't disagree. So what do you think about arguably more intuitive format (e.g. "12 s") provided as property editor, with the intention to cover said configuration purposes? Would such a think find its place in Spring?