I have added a new endpoint to my Swagger v2 specification, that is being used in a Java 8 Spring-Boot application using SpringFox for code generation.
The code generation is successful and the app compiles, but the @RestController cannot start up. All tests and normal start up sequence fail with the following error message, even those unrelated to the new endpoint:
[ERROR] someUnitTest(com.mycompany.api.corporate.server.controller.SomeControllerTest) Time elapsed: 0 s <<< ERROR!
java.lang.IllegalStateException: Failed to load ApplicationContext
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'documentationPluginsBootstrapper' defined in URL [jar:file:/root/.m2/repository/io/springfox/springfox-spring-web/2.8.0/springfox-spring-web-2.8.0.jar!/springfox/documentation/spring/web/plugins/DocumentationPluginsBootstrapper.class]: Unsatisfied dependency expressed through constructor parameter 1;
nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webMvcRequestHandlerProvider' defined in URL [jar:file:/root/.m2/repository/io/springfox/springfox-spring-web/2.8.0/springfox-spring-web-2.8.0.jar!/springfox/documentation/spring/web/plugins/WebMvcRequestHandlerProvider.class]: Unsatisfied dependency expressed through constructor parameter 1;
nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Invalid mapping on handler class [com.mycompany.api.corporate.server.controller.OrderController]: public org.springframework.http.ResponseEntity com.mycompany.api.corporate.server.controller.OrderController.finishOrder(com.mycompany.api.corporate.server.model.CustomerData,java.lang.String)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webMvcRequestHandlerProvider' defined in URL [jar:file:/root/.m2/repository/io/springfox/springfox-spring-web/2.8.0/springfox-spring-web-2.8.0.jar!/springfox/documentation/spring/web/plugins/WebMvcRequestHandlerProvider.class]: Unsatisfied dependency expressed through constructor parameter 1;
nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Invocation of init method failed;
nested exception is java.lang.IllegalStateException: Invalid mapping on handler class [com.mycompany.api.corporate.server.controller.OrderController]: public org.springframework.http.ResponseEntity com.mycompany.api.corporate.server.controller.OrderController.finishOrder(com.mycompany.api.corporate.server.model.CustomerData,java.lang.String)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Invalid mapping on handler class [com.mycompany.api.corporate.server.controller.OrderController]: public org.springframework.http.ResponseEntity com.mycompany.api.corporate.server.controller.OrderController.finishOrder(com.mycompany.api.corporate.server.model.CustomerData,java.lang.String)
Caused by: java.lang.IllegalStateException: Invalid mapping on handler class [com.mycompany.api.corporate.server.controller.OrderController]: public org.springframework.http.ResponseEntity com.mycompany.api.corporate.server.controller.OrderController.finishOrder(com.mycompany.api.corporate.server.model.CustomerData,java.lang.String)
Caused by: org.springframework.http.InvalidMediaTypeException: Invalid mime type "headers": does not contain '/'
Caused by: org.springframework.util.InvalidMimeTypeException: Invalid mime type "headers": does not contain '/'
Given the trace, I think that the problem lies in this endpoint:
/order/{id}/finish:
post:
tags:
- Order
summary: TODO
description: TODO
operationId: finishOrder
produces:
- application/json
parameters:
- in: path
name: id
required: true
description: TODO
type: string
- in: body
name: customerData
required: true
description: TODO
schema:
$ref: "#/definitions/CustomerData"
responses:
201:
description: Account created
schema:
$ref: "#/definitions/StatusMessage"
examples:
application/json:
code: "00000"
headers:
Location:
type: string
description: Resource location to be used for later
400:
description: >
Failed to create the account.
See error code and message in object.
schema:
$ref: "#/definitions/StatusMessage"
examples:
application/json:
code: "31120"
message: "Last name is too long"
Why do the code generation and build work but not the execution?
There is a syntax error in the specification, that is not being picked up by the Swagger Editor or the Codegen plugin:
responses:
201:
description: Account created
schema:
$ref: "#/definitions/StatusMessage"
examples:
application/json:
code: "00000"
headers: # This is the problem: response headers should not be defined here
Location:
type: string
description: Resource location to be used for later
The application interpreted headers in the first variant as a media type (which is what it expects at this place); a valid media type should have a / in the middle; this is exactly what the error message is saying.
The correct way to declare response headers would be:
responses:
201:
description: Account created
schema:
$ref: "#/definitions/StatusMessage"
headers:
Location:
type: string
description: Resource location to be used for later
examples:
application/json:
code: "00000"
This way, the definition is correctly picked up and the response header appears in the generated HTML in the Swagger Editor.