java.time.Duration properties can't be injected through @Value

[detouched]

Introduced in #11078 injection of java.time.Duration properties is incomplete. It works for properties injected into a structured object through @ConfigurationProperties, but it does not work for properties injected through @Value.

E.g. something like this:

    @Bean
    public String demoBean(@Value("property") Duration property) {
        return "I was given a property through @Value: " + property;
    }

fails to start up with an error:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'demoBean' defined in com.github.detouched.DemoValueApp: Unsatisfied dependency expressed through method 'demoBean' parameter 0; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'java.time.Duration'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'java.time.Duration': no matching editors or conversion strategy found
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:729) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:470) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1254) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1103) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:541) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:501) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:760) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869) ~[spring-context-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.builder.SpringApplicationBuilder.run(SpringApplicationBuilder.java:137) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at com.github.detouched.DemoValueApp.main(DemoValueApp.java:23) [classes/:na]
Caused by: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'java.time.Duration'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'java.time.Duration': no matching editors or conversion strategy found
	at org.springframework.beans.TypeConverterSupport.doConvert(TypeConverterSupport.java:77) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.TypeConverterSupport.convertIfNecessary(TypeConverterSupport.java:52) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1093) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:815) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:721) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	... 18 common frames omitted
Caused by: java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'java.time.Duration': no matching editors or conversion strategy found

Meanwhile this works just fine:

    @Bean
    public String demoBean(Props props) {
        return "I was given a property through @ConfigurationProperties: " + props.getProperty();
    }

    @ConfigurationProperties
    public static class Props {
        private Duration property;

        public Duration getProperty() {
            return property;
        }

        public void setProperty(Duration property) {
            this.property = property;
        }
    }

This looks at least inconsistent and doesn't allow the short syntax.

You can find the full code for both use cases in this repository.

[snicoll]

Introduced in #11078 injection of java.time.Duration properties is incomplete.

I can understand why you feel that way but it isn't. The purpose of that issue was to upgrade Spring Boot's binding and @Value is a framework feature. It would be nice if our converters were also registered in the context though.

[philwebb]

We considered that but the ApplicationConversionService was added quite late so we didn't want to risk registering it by default. I think this is probably a duplicate of #12148 which we might want to consider again for 2.1.

[detouched]

Cool, thanks for the explanation. I'll watch #12148 then, I'm happy to close this one if it doesn't make sense on its own.

Is there a reason why Spring Boot has its own conversion mechanism and converters? Properties resolution seems something fundamental to me.

[philwebb]

@detouched The Duration conversion was added primarily for application.properties support and initially was part of the Binder. Fairly late in the day we realized a general application conversion service would be a good idea. The ConversionService in Spring Boot builds on the one in Spring Framework. It's quite possible that in the future some of these converters might get moved up.

[detouched]

Ok, I see the picture now. Well, looking forward to the next releases then :)

[snicoll]

Thanks @detouched, we've discussed this today and #12148 is our proposal to support this.