In Gradle 4.x, SourceSetOutput now has multiple classes directories
and getClassesDir() has been deprecated. This commit introduces the
use of reflection to use getClassesDirs() when it's available rather
than getClassesDir().
Closes gh-9559
Previously JsonComponentModule tried to instantiate all
inner classes and failed with InstantiationException when
the class is abstract and extends JsonSerializer/JsonDeserializer.
With this change is now possible to have common logic inner abstract classes.
See gh-9443
In an MVC web application, DelegatingWebMvcConfiguration provides the
ConversionService while also consuming WebMvcConfigurerAdapters that,
among other things, can configure HTTP message converters. Boot's
WebMvcConfigurerAdapter, WebMvcAutoConfigurationAdapter, consumes
the HttpMessageConverters bean and uses it to configure Spring MVC's
HTTP message converters. This can create a bean dependency cycle if
an HTTP message converter bean depends, directly or indirectly on
the ConversionService. An example of the cycle is:
┌─────┐
| jsonComponentConversionServiceCycle.ThingDeserializer defined in …
↑ ↓
| org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$EnableWebMvcConfiguration
↑ ↓
| org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter
↑ ↓
| org.springframework.boot.autoconfigure.web.HttpMessageConvertersAutoConfiguration
↑ ↓
| mappingJackson2HttpMessageConverter defined in class path resource [org/springframework/boot/autoconfigure/web/JacksonHttpMessageConvertersConfiguration$MappingJackson2HttpMessageConverterConfiguration.class]
↑ ↓
| jacksonObjectMapper defined in class path resource [org/springframework/boot/autoconfigure/jackson/JacksonAutoConfiguration$JacksonObjectMapperConfiguration.class]
└─────┘
This commit breaks the cycle by making WebMvcAutoConfigurationAdapter
consume HttpMessageConverters lazily. This allows the adapter to be
created without triggered instantiation of every HTTP message
converter bean and all their dependencies. This allows it to be
injected into DelegatingWebMvcConfiguration without triggering an
attempt to retrieve the ConversionService.
Closes gh-9409
Andy Wilkinson
Stephane Nicoll
Huang YunKun
Dave Syer
Madhura Bhave
Vladimir Tsanev
Akihiro Kondo
Spring Buildmaster
Artem Bilan