Unable to bring up swagger-ui from spring-boot application

Question

I have a spring boot application that i am running using embedded tomcat server. I am partially successful in getting springfox-swagger integrated with the app. If i do a /v2/api-docs , i am able to see all the documentation of all the api's in the webapp. However, when i am trying to access the same from UI, it does not work. Below are the detailed results.

Output of - localhost:8080/api/swagger-resources

[ {   "name" : "default",   "location" : "/v2/api-docs",   "swaggerVersion" : "2.0" } ] 

Output of - localhost:8080/api/v2/api-docs

I get valid results. I can confirm that and the output is too large to paste here 

But when i try to access the swagger-ui, it does not work. Below are the different URL's i invoked to access the swagger-ui.

http://localhost:8080/swagger-ui.html - UI is loading, but no documentation of API's is present http://localhost:8080/api/swagger-ui.html  - 404 Not Found http://localhost:8080/springfox - 404 Not Found http://localhost:8080/api/springfox - 404 Not Found 

Below is my SwaggerConfig.java class

package com.vmware.vrack.lcm;  import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import springfox.documentation.builders.RequestHandlerSelectors; import springfox.documentation.service.ApiInfo; import springfox.documentation.spi.DocumentationType; import springfox.documentation.spring.web.plugins.Docket; import springfox.documentation.swagger.web.UiConfiguration; import springfox.documentation.swagger2.annotations.EnableSwagger2;  import static springfox.documentation.builders.PathSelectors.regex;  @Configuration @EnableSwagger2 public class SwaggerConfig {      @Bean     public Docket api() {         return new Docket(DocumentationType.SWAGGER_2)                 .select()                 .apis(RequestHandlerSelectors.any())                 .paths(regex("/.*"))                 .build()                 .apiInfo(apiInfo());     }      private ApiInfo apiInfo() {         ApiInfo apiInfo = new ApiInfo(                 "My Project's REST API",                 "This is a description of your API.",                 "version-1",                 "API TOS",                 "[email protected]",                 "API License",                 "API License URL"         );         return apiInfo;     }  } 

Below are the swagger dependencies i am using

<dependency>    <groupId>io.springfox</groupId>    <artifactId>springfox-swagger2</artifactId>    <version>2.2.2</version> </dependency> <dependency>    <groupId>io.springfox</groupId>    <artifactId>springfox-swagger-ui</artifactId>    <version>2.2.2</version> </dependency> 

Below is the message converter webconfig file

@Configuration @EnableWebMvc public class WebConfig extends WebMvcConfigurerAdapter {      @Override     public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {         converters.add(jackson2Converter());     }      @Bean     public MappingJackson2HttpMessageConverter jackson2Converter() {         MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();         converter.setObjectMapper(objectMapper());         return converter;     }      @Bean     public ObjectMapper objectMapper() {         ObjectMapper objectMapper = new ObjectMapper();         objectMapper.enable(SerializationFeature.INDENT_OUTPUT);         return objectMapper;     } } 

The below link says that @EnableWebMvc should not be used in a spring-boot webapp and using the annotation might cause issues in bringing swagger-ui up. But, if i do not use the annotation, the web-app is not coming up (i have pasted the error stack trace below)

http://springfox.github.io/springfox/docs/current/#configuring-the-objectmapper

Error trace when i don't use the @EnableWebMvc Annotation

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'documentationPluginsBootstrapper' defined in URL [jar:file:/Users/ngorijala/.m2/repository/io/springfox/springfox-spring-web/2.2.2/springfox-spring-web-2.2.2.jar!/springfox/documentation/spring/web/plugins/DocumentationPluginsBootstrapper.class]: Unsatisfied dependency expressed through constructor argument with index 1 of type [springfox.documentation.spi.service.RequestHandlerProvider]: : Error creating bean with name 'webMvcRequestHandlerProvider' defined in URL [jar:file:/Users/ngorijala/.m2/repository/io/springfox/springfox-spring-web/2.2.2/springfox-spring-web-2.2.2.jar!/springfox/documentation/spring/web/plugins/WebMvcRequestHandlerProvider.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [java.util.List]: : No qualifying bean of type [org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping] found for dependency [collection of org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping] found for dependency [collection of org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webMvcRequestHandlerProvider' defined in URL [jar:file:/Users/ngorijala/.m2/repository/io/springfox/springfox-spring-web/2.2.2/springfox-spring-web-2.2.2.jar!/springfox/documentation/spring/web/plugins/WebMvcRequestHandlerProvider.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [java.util.List]: : No qualifying bean of type [org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping] found for dependency [collection of org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping] found for dependency [collection of org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}     at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749)     at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:185)     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1139)     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1042)     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)     at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)     at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)     at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)     at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)     at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:755)     at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)     at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)     at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403)     at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)     at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)     at org.eclipse.jetty.server.handler.ContextHandler.callContextInitialized(ContextHandler.java:799)     at org.eclipse.jetty.servlet.ServletContextHandler.callContextInitialized(ServletContextHandler.java:499)     at org.eclipse.jetty.server.handler.ContextHandler.startContext(ContextHandler.java:790)     at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:337)     at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1343)     at org.eclipse.jetty.maven.plugin.JettyWebAppContext.startWebapp(JettyWebAppContext.java:296)     at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1336)     at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:742)     at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:499)     at org.eclipse.jetty.maven.plugin.JettyWebAppContext.doStart(JettyWebAppContext.java:365)     at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)     at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)     at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)     at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)     at org.eclipse.jetty.server.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:163) 

I have a feeling that i am missing something trivial. Can someone please take a look and let me know what i am missing.?? Thanks in advance.!!

Answer 1

If you want to keep @EnableWebMvc annotation any way, you have to add the following

  @Override     public void addResourceHandlers(ResourceHandlerRegistry registry) {              registry.addResourceHandler("swagger-ui.html")                     .addResourceLocations("classpath:/META-INF/resources/");              registry.addResourceHandler("/webjars/**")                     .addResourceLocations("classpath:/META-INF/resources/webjars/");      } 

Answer 2

springfox-swagger-ui is a web jar and requires that you set up resource handlers to inform the dispatch servlet how and which resource to serve up when you ask for ../swagger-ui.html. Usually in a spring-boot application auto-configuration takes care of setting it up for you. The reason its not loading in your case is because you've signaled to spring-boot that the application is going to be manually configured via the WebMvcConfigurerAdapter/@EnableWebMvc combination.

You should be able to place the @SpringBootApplication annotation on your main spring configuration and get rid of the WebConfig class all-together.

Since your WebConfig isn't adding any value other than making sure the JSON is indented, I'd suggest removing it all-together and replacing it with a Jackson2ObjectMapperBuilder bean instead.

For examples on how to do the same thing in spring-mvc/spring-boot etc. take a look at the springfox-demos project. In particular take a look at SpringConfig to see how to manually configure the resource handlers.