SpringDocJacksonModuleConfiguration is loaded even though there is no ObjectMapperProvider when springdoc.api-docs.enabled = false

[davefranken-ah]

Describe the bug
Caused by: #2114

Usually, Springdoc configuration classes include an annotation @ConditionalOnBean(SpringDocConfiguration.class), this ensures they are only loaded if the beans from that configuration are loaded.

SpringDocJacksonModuleConfiguration does not have such an annotation. Thus, the constructor inside it is fired, which requires a bean of type ObjectMapperProvider, which is not available when springdoc.api-docs.enabled = false.

To Reproduce
Steps to reproduce the behavior:

• What version of spring-boot you are using? 3.0.4
• What modules and versions of springdoc-openapi are you using? 2.0.4
• What is the actual and the expected result using OpenAPI Description (yml or json)?
  There should not be an error
• Provide with a sample code (HelloController) or Test that reproduces the problem
  In application.yml (or .properties), set springdoc.api-docs.enabled to false
  Try to start an application or run a test

Expected behavior
The application should start and/or tests should run

Additional context
This is likely caused by #2114 where the SpringDocJacksonModuleConfiguration was added without the proper annotations.

[davefranken-ah]

This may help others: until a new version is released, you can use the following workaround:

class SpringDocJacksonKotlinModuleConfigurationFilter : AutoConfigurationImportFilter, EnvironmentAware {

    private lateinit var environment: Environment

    override fun match(autoConfigurationClasses: Array<out String>, autoConfigurationMetadata: AutoConfigurationMetadata?): BooleanArray {
        if (environment.getProperty("springdoc.api-docs.enabled", Boolean::class.java) == false) {
            return autoConfigurationClasses.map { it != CLASS_TO_EXCLUDE }.toBooleanArray()
        }

        return BooleanArray(autoConfigurationClasses.size) { true }
    }

    companion object {
        private const val CLASS_TO_EXCLUDE = "org.springdoc.core.configuration.SpringDocJacksonKotlinModuleConfiguration"
    }

    override fun setEnvironment(environment: Environment) {
        this.environment = environment
    }
}

This will exclude the SpringDocJacksonKotlinModuleConfiguration file being loaded through auto-configuration whenever the property springdoc.api-docs.enabled is set to false (which leads to SpringDocConfiguration and consequently ObjectMapperProvider not being loaded).

You can add this file to META-INF/spring.factories:
org.springframework.boot.autoconfigure.AutoConfigurationImportFilter=my.package.SpringDocJacksonKotlinModuleConfigurationFilter

[jurri-cz]

There is a lighter workaround for Spring Boot (3.x included). Use in external config file where your springdoc.api-docs.enabled=false is:

spring:
  autoconfigure:
    exclude: org.springdoc.core.configuration.SpringDocJacksonKotlinModuleConfiguration