Declaring a bean named conversionService prevents binding of Duration configuration properties

[fprochazka]

Hello,
I have the following problem and I believe it might be a bug.

---

I have a multi-module application

• core - working perfectly
• rest-api - working perfectly (depends on core)
• web-admin - I'm currently creating this module (depends on core)

@SpringBootConfiguration
@Import({
    CoreBootstrap.class, // config from module core
    WebConfiguration.class,
    WebSecurityConfiguration.class,
})
@PropertySource("classpath:application-web-admin.properties")
public class WebAdminApplication
{

    public static void main(final String[] args)
    {
        new SpringApplicationBuilder(WebAdminApplication.class)
            .registerShutdownHook(true)
            .bannerMode(Banner.Mode.OFF)
            .web(WebApplicationType.SERVLET)
            .run(args);
    }

}

@Configuration
@EnableWebSecurity
public class WebSecurityConfiguration extends WebSecurityConfigurerAdapter
{
    ...

@Configuration
@Import({
    ForwardedHeadersConfiguration.class, // enables ForwardedHeaderFilter
})
@EnableWebMvc
public class WebConfiguration implements WebMvcConfigurer
{
    ...

File application-web-admin.properties

server.servlet.context-path=/
spring.jpa.open-in-view=false
spring.mvc.throw-exception-if-no-handler-found=true
spring.http.encoding.charset=UTF-8
spring.http.encoding.enabled=true
spring.http.encoding.force=true
spring.security.filter.order=10
spring.thymeleaf.enabled=true
spring.mvc.locale-resolver=FIXED
spring.mvc.locale=en
#spring.resources.cache.period=1s
#spring.mvc.contentnegotiation.favor-parameter=false
#spring.mvc.contentnegotiation.favor-path-extension=false
management.endpoint.health.showDetails=WHEN_AUTHORIZED
management.endpoint.health.roles=ACTUATOR

---

Now - I've been struggling to figure out, why my static resources are returning 404 - and I believe I might have found the reason thanks to this SO answer, so I've removed the @EnableWebMvc annotation and suddenly this:

23:19:47.623 [main] DEBUG org.springframework.boot.devtools.restart.ChangeableUrls - Matching URLs for reloading : [******]
23:19:53.453 [restartedMain  ] INFO                 com.cogvio.WebAdminApplication:	Starting WebAdminApplication
23:19:53.454 [restartedMain  ] DEBUG                com.cogvio.WebAdminApplication:	Running with Spring Boot v2.0.0.RC2, Spring v5.0.4.RELEASE 
23:19:57.191 [localhost-start] INFO  org.springframework.web.context.ContextLoader:	Root WebApplicationContext: initialization completed in 3684 ms 
23:31:27.431 [restartedMain  ] WARN  ationConfigServletWebServerApplicationContext:	Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration': Unsatisfied dependency expressed through method 'setFilterChainProxySecurityConfigurer' parameter 1; nested exception is org.springframework.beans.factory.BeanExpressionException: Expression parsing failed; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'com.cogvio.config.WebSecurityConfiguration': Unsatisfied dependency expressed through method 'setContentNegotationStrategy' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$EnableWebMvcConfiguration': Unsatisfied dependency expressed through method 'setConfigurers' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.boot.context.properties.ConfigurationPropertiesBindException: Error creating bean with name 'spring.resources-org.springframework.boot.autoconfigure.web.ResourceProperties': Could not bind properties to 'ResourceProperties' : prefix=spring.resources, ignoreInvalidFields=false, ignoreUnknownFields=false; nested exception is org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'spring.resources.cache.period' to java.time.Duration 
23:31:28.634 [restartedMain  ] ERROR        o.s.b.d.LoggingFailureAnalysisReporter:	

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to bind properties under 'spring.resources.cache.period' to java.time.Duration:

    Property: spring.resources.cache.period
    Value: 0
    Origin: "spring.resources.cache.period" from property source "refresh"
    Reason: No converter found capable of converting from type [java.lang.String] to type [@org.springframework.boot.convert.DurationUnit java.time.Duration]

Action:

Update your application's configuration

I've tried to step-debug it, but there is multiple conversion services, some of them are static and the binding is happening behind 30+ layers of method calls.

If I uncomment this, nothing changes - the error message stays the same (the Value: 0 doesn't change)

spring.resources.cache.period=1s

I believe the value comes from here

If I remove this from my pom.xml, it starts working

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>

---

After I've "fixed" all this, I've decided that I want to change those settings, so I've set

spring.resources.cache.cachecontrol.maxAge=P365D

but - the same problem

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to bind properties under 'spring.resources.cache.cachecontrol.max-age' to java.time.Duration:

    Property: spring.resources.cache.cachecontrol.maxage
    Value: P365D
    Origin: "spring.resources.cache.cachecontrol.maxAge" from property source "class path resource [application-web-admin.properties]"
    Reason: No converter found capable of converting from type [java.lang.String] to type [@org.springframework.boot.convert.DurationUnit java.time.Duration]

Action:

Update your application's configuration

Which leads me to think, that Spring Boot contains properties that you simply cannot configure, without creating a custom converter.

[fprochazka]

The only thing that worked was this - I haven't found a way to register a converter (as the error message suggests) that would work with *.properties

@Configuration
public class ConversionsConfiguration
{

    @Bean
    public CustomEditorConfigurer customEditorConfigurer()
    {
        CustomEditorConfigurer configurer = new CustomEditorConfigurer();
        configurer.setPropertyEditorRegistrars(new PropertyEditorRegistrar[]{
            stringToDurationPropertyEditorRegistrar(),
        });
        return configurer;
    }

    @Bean
    public PropertyEditorRegistrar stringToDurationPropertyEditorRegistrar()
    {
        return registry -> registry.registerCustomEditor(
            Duration.class,
            new ConvertingPropertyEditorAdapter(
                ApplicationConversionService.getSharedInstance(),
                TypeDescriptor.valueOf(Duration.class)
            )
        );
    }

}

Now I can configure

spring.resources.cache.cachecontrol.maxAge=P365D

and the application works even with spring-boot-devtools

[snicoll]

@fprochazka can you please try your application with Spring Boot 2.0.0.BUILD.SNAPSHOT? What version of Spring Boot is this? Is it working with an earlier milestone?

[snicoll]

For the record, I've been trying to reproduce this problem with 2.0.0.RC2 and wasn't unable to.

[fprochazka]

You can see it in the logs included

Running with Spring Boot v2.0.0.RC2, Spring v5.0.4.RELEASE

I will try to create a minimal reproducible version, but I might not get to it today.

[snicoll]

We are releasing GA tomorrow so I'd appreciate some help here. For a start can you try with the snapshot please?

[snicoll]

Did it work with a previous milestone?

[wilkinsona]

@fprochazka Have you declared a bean named conversionService in your application? If so, it will be the conversion service that's used for configuration property binding. You'll see the failure you've reported if it is not capable of converting a String to a Duration.

[wilkinsona]

This looks to be a regression in RC2.

In RC2 and master, the DevTools sample fails to start with this change:

diff --git a/spring-boot-samples/spring-boot-sample-devtools/src/main/java/sample/devtools/SampleDevToolsApplication.java b/spring-boot-samples/spring-boot-sample-devtools/src/main/java/sample/devtools/SampleDevToolsApplication.java
index e10f482e0d..1d6dff3990 100644
--- a/spring-boot-samples/spring-boot-sample-devtools/src/main/java/sample/devtools/SampleDevToolsApplication.java
+++ b/spring-boot-samples/spring-boot-sample-devtools/src/main/java/sample/devtools/SampleDevToolsApplication.java
@@ -18,6 +18,9 @@ package sample.devtools;

 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.core.convert.ConversionService;
+import org.springframework.core.convert.support.DefaultConversionService;

 @SpringBootApplication
 public class SampleDevToolsApplication {
@@ -26,4 +29,9 @@ public class SampleDevToolsApplication {
                SpringApplication.run(SampleDevToolsApplication.class, args);
        }

+       @Bean
+       public ConversionService conversionService() {
+               return DefaultConversionService.getSharedInstance();
+       }
+
 }

The problem does not occur with RC1.