Configuring Swagger UI with Spring Boot

Question

I am trying to configure Swagger UI with my Spring boot application. Although the v2/api-docs seems to be loading properly, the http://localhost:8080/swagger-ui.html does not load my annotated REST API.

Here is what I have:

pom.xml:

...
<!--Swagger UI-->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.6.1</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.4.0</version>
        </dependency>
...

SwaggerConfig.java

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.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;
    }
}

http://localhost:8080/v2/api-docs:

{"swagger":"2.0","info":{"description":"This is a description of your API.","version":"version-1","title":"My Project's REST API","termsOfService":"API TOS","contact":{"name":"[email protected]"},"license":{"name":"API License","url":"API License URL"}},"host":"localhost:8080","basePath":"/","tags":[{"name":"test-controller","description":"Test Controller"},{"name":"custom-field-controller","description":"Custom Field Controller"},{"name":"user-controller","description":"User Controller"},{"name":"users-controller","description":"Users Controller"},{"name":"crudapi-controller","description":"CRUDAPI Controller"},{"name":"basic-error-controller","description":"Basic Error Controller"}],"paths":{"/":{"get":{"tags":["crudapi-controller"],"summary":"greeting","operationId":"greetingUsingGET","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"string"}},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}}},"/api/javainuse":{"get":{"tags":["test-controller"],"summary":"firstPage","operationId":"firstPageUsingGET","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"string"}},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}}},"/error":{"get":{"tags":["basic-error-controller"],"summary":"errorHtml","operationId":"errorHtmlUsingGET","consumes":["application/json"],"produces":["text/html"],"responses":{"200":{"description":"OK","schema":{"$ref":"#/definitions/ModelAndView"}},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}},"head":{"tags":["basic-error-controller"],"summary":"errorHtml","operationId":"errorHtmlUsingHEAD","consumes":["application/json"],"produces":["text/html"],"responses":{"200":{"description":"OK","schema":{"$ref":"#/definitions/ModelAndView"}},"401":{"description":"Unauthorized"},"204":{"description":"No Content"},"403":{"description":"Forbidden"}}},"post":{"tags":["basic-error-controller"],"summary":"errorHtml","operationId":"errorHtmlUsingPOST","consumes":["application/json"],"produces":["text/html"],"responses":{"200":{"description":"OK","schema":{"$ref":"#/definitions/ModelAndView"}},"201":{"description":"Created"},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}},"put":{"tags":["basic-error-controller"],"summary":"errorHtml","operationId":"errorHtmlUsingPUT","consumes":["application/json"],"produces":["text/html"],"responses":{"200":{"description":"OK","schema":{"$ref":"#/definitions/ModelAndView"}},"201":{"description":"Created"},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}},"delete":{"tags":["basic-error-controller"],"summary":"errorHtml","operationId":"errorHtmlUsingDELETE","consumes":["application/json"],"produces":["text/html"],"responses":{"200":{"description":"OK","schema":{"$ref":"#/definitions/ModelAndView"}},"401":{"description":"Unauthorized"},"204":{"description":"No Content"},"403":{"description":"Forbidden"}}},"options":{"tags":["basic-error-controller"],"summary":"errorHtml","operationId":"errorHtmlUsingOPTIONS","consumes":["application/json"],"produces":["text/html"],"responses":{"200":{"description":"OK","schema":{"$ref":"#/definitions/ModelAndView"}},"401":{"description":"Unauthorized"},"204":{"description":"No Content"},"403":{"description":"Forbidden"}}},"patch":{"tags":["basic-error-controller"],"summary":"errorHtml","operationId":"errorHtmlUsingPATCH","consumes":["application/json"],"produces":["text/html"],"responses":{"200":{"description":"OK","schema":{"$ref":"#/definitions/ModelAndView"}},"401":{"description":"Unauthorized"},"204":{"description":"No Content"},"403":{"description":"Forbidden"}}}},"/fields":{"get":{"tags":["custom-field-controller"],"summary":"greeting","operationId":"greetingUsingGET_1","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"string"}},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}}},"/fields/{id}":{"get":{"tags":["custom-field-controller"],"summary":"fieldAPIController","operationId":"fieldAPIControllerUsingGET","consumes":["application/json"],"produces":["*/*"],"parameters":[{"name":"id","in":"path","description":"id","required":true,"type":"integer","format":"int32"}],"responses":{"200":{"description":"OK","schema":{"type":"array","items":{"$ref":"#/definitions/CustomField"}}},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}}},"/users":{"get":{"tags":["user-controller"],"summary":"greeting","operationId":"greetingUsingGET_2","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"string"}},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}}},"/users/":{"get":{"tags":["users-controller"],"summary":"listUsers","operationId":"listUsersUsingGET","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"array","items":{"$ref":"#/definitions/UserJPA"}}},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}},"head":{"tags":["users-controller"],"summary":"listUsers","operationId":"listUsersUsingHEAD","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"array","items":{"$ref":"#/definitions/UserJPA"}}},"401":{"description":"Unauthorized"},"204":{"description":"No Content"},"403":{"description":"Forbidden"}}},"post":{"tags":["users-controller"],"summary":"listUsers","operationId":"listUsersUsingPOST","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"array","items":{"$ref":"#/definitions/UserJPA"}}},"201":{"description":"Created"},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}},"put":{"tags":["users-controller"],"summary":"listUsers","operationId":"listUsersUsingPUT","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"array","items":{"$ref":"#/definitions/UserJPA"}}},"201":{"description":"Created"},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}},"delete":{"tags":["users-controller"],"summary":"listUsers","operationId":"listUsersUsingDELETE","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"array","items":{"$ref":"#/definitions/UserJPA"}}},"401":{"description":"Unauthorized"},"204":{"description":"No Content"},"403":{"description":"Forbidden"}}},"options":{"tags":["users-controller"],"summary":"listUsers","operationId":"listUsersUsingOPTIONS","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"array","items":{"$ref":"#/definitions/UserJPA"}}},"401":{"description":"Unauthorized"},"204":{"description":"No Content"},"403":{"description":"Forbidden"}}},"patch":{"tags":["users-controller"],"summary":"listUsers","operationId":"listUsersUsingPATCH","consumes":["application/json"],"produces":["*/*"],"responses":{"200":{"description":"OK","schema":{"type":"array","items":{"$ref":"#/definitions/UserJPA"}}},"401":{"description":"Unauthorized"},"204":{"description":"No Content"},"403":{"description":"Forbidden"}}}},"/users/{id}":{"get":{"tags":["user-controller"],"summary":"userAPIController","operationId":"userAPIControllerUsingGET","consumes":["application/json"],"produces":["*/*"],"parameters":[{"name":"id","in":"path","description":"id","required":true,"type":"integer","format":"int32"}],"responses":{"200":{"description":"OK","schema":{"$ref":"#/definitions/Collection«UserJPA»"}},"401":{"description":"Unauthorized"},"403":{"description":"Forbidden"},"404":{"description":"Not Found"}}}}},"definitions":{"UserJPA":{"type":"object"},"Collection«UserJPA»":{"type":"object"},"ModelAndView":{"type":"object","properties":{"empty":{"type":"boolean"},"model":{"type":"object"},"modelMap":{"type":"object","additionalProperties":{"type":"object"}},"reference":{"type":"boolean"},"status":{"type":"string","enum":["100","101","102","103","200","201","202","203","204","205","206","207","208","226","300","301","302","303","304","305","307","308","400","401","402","403","404","405","406","407","408","409","410","411","412","413","414","415","416","417","418","419","420","421","422","423","424","426","428","429","431","451","500","501","502","503","504","505","506","507","508","509","510","511"]},"view":{"$ref":"#/definitions/View"},"viewName":{"type":"string"}}},"CustomField":{"type":"object","properties":{"name":{"type":"string"}}},"View":{"type":"object","properties":{"contentType":{"type":"string"}}}}}

The swagger-ui.html (http://localhost:8080/swagger-ui.html) does not show the expected REST calls:

The error in swagger-ui.html from the code inspection: Failed to load resource: the server responded with a status of 404 ().

I have googled around (tried web-config mvc too) but the error persists. Maybe I am missing a resource reference in the .iml file?

Answer 1

I had this issue today and fixed it by matching up the versions of my springfox-swagger2 and springfox-swagger-ui dependencies:

    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger2</artifactId>
        <version>2.6.1</version>
    </dependency>
    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger-ui</artifactId>
        <version>2.6.1</version>
    </dependency>

There's very little other code to just get it up and running. One simple config class:

@Configuration
@EnableSwagger2
class SwaggerConfiguration {

    @Bean
    public Docket api() {
        return new Docket(DocumentationType.SWAGGER_2)
                .select()
                .apis(RequestHandlerSelectors.basePackage("com.foo.samples.swaggersample"))
                .paths(PathSelectors.any())
                .build();
    }

}

And my application.properties

# location of the swagger json
springfox.documentation.swagger.v2.path=/swagger.json

(This is in Spring Boot).

Answer 2

Statement : Generate Swagger UI for the listing of all the REST APIs through Spring Boot Application.

Follow the below steps to generate the Swagger UI through Spring Boot application:

1. Add following dependency in pom.xml –

    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger2</artifactId>
        <version>2.6.1</version>
    </dependency>

    <dependency>
        <groupId>io.springfox</groupId>
        <artifactId>springfox-swagger-ui</artifactId>
        <version>2.6.1</version>
    </dependency>

2. Add the following piece of code in your main application class having the @EnableSwagger2 annotation.

    @EnableSwagger2
    @SpringBootApplication
    public class MyApp {
    public static void main(String[] args) {
        SpringApplication.run(MyApp.class, args);
    }

    @Bean
    public Docket api() {
        return new Docket(DocumentationType.SWAGGER_2).select()  
           .apis(RequestHandlerSelectors.withClassAnnotation(Api.class))
           .paths(PathSelectors.any()).build().pathMapping("/")
           .apiInfo(apiInfo()).useDefaultResponseMessages(false);
    }

    @Bean
    public ApiInfo apiInfo() {
        final ApiInfoBuilder builder = new ApiInfoBuilder();
        builder.title("My Application API through Swagger UI").version("1.0").license("(C) Copyright Test")
        .description("List of all the APIs of My Application App through Swagger UI");
        return builder.build();
        }
    }

3. Add the below RootController class in your code to redirect to the Swagger UI page. In this way, you don’t need to put the dist folder of Swagger-UI in your resources directory.

    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    @Controller
    @RequestMapping("/")
    public class RootController {
        @RequestMapping(method = RequestMethod.GET)
        public String swaggerUi() {
            return "redirect:/swagger-ui.html";
        }
    }

4. Being the final steps, add the @Api and @ApiOperation notation in all your RESTControllers like below –

    import static org.springframework.web.bind.annotation.RequestMethod.GET;
    import org.springframework.http.HttpStatus;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.ResponseStatus;
    import org.springframework.web.bind.annotation.RestController;
    import io.swagger.annotations.Api;
    import io.swagger.annotations.ApiOperation;

    @RestController
    @RequestMapping("/hello")
    @Api(value = "hello", description = "Sample hello world application")
    public class TestController {

        @ApiOperation(value = "Just to test the sample test api of My App Service")
        @RequestMapping(method = RequestMethod.GET, value = "/test")
        // @Produces(MediaType.APPLICATION_JSON)
        public String test() {
            return "Hello to check Swagger UI";
        }

        @ResponseStatus(HttpStatus.OK)
        @RequestMapping(value = "/test1", method = GET)
        @ApiOperation(value = "My App Service get test1 API", position = 1)
        public String test1() {
            System.out.println("Testing");
            if (true) {
                return "Tanuj";
            }
            return "Gupta";
        }
    }

Now your are done. Now to run your Spring Boot Application, go to browser and type localhost:8080. You will see Swagger UI having all the details of your REST APIs.

Happy Coding. 🙂
The source code of the above implementation is also on my blog if you feel like checking it out.