POM.xml

• Add the following Maven dependencies for OAS 2

<dependency>
   <groupId>io.springfox</groupId>
   <artifactId>springfox-swagger2</artifactId>
   <version>2.9.2</version>
</dependency>
<dependency>
   <groupId>io.springfox</groupId>
   <artifactId>springfox-swagger-ui</artifactId>
   <version>2.9.2</version>
</dependency>
<dependency>
   <groupId>javax.xml.bind</groupId>
   <artifactId>jaxb-api</artifactId>
   <version>2.3.1</version>
</dependency>

• Add plugin to generate OAS definition; config package name and output location

<plugin>
   <groupId>com.github.kongchen</groupId>
   <artifactId>swagger-maven-plugin</artifactId>
   <version>3.1.7</version>
   <configuration>
      <apiSources>
         <apiSource>
            <springmvc>true</springmvc>
            <locations>
               <location>com.wmock.info</location>
            </locations>
            <outputFormats>yaml</outputFormats>
            <schemes>
               <scheme>http</scheme>
            </schemes>
            <info>
               <title>API Doc</title>
               <version>1.0</version>
               <description>OAS 2.0 documentation</description>
            </info>
            <swaggerDirectory>${basedir}/target/swagger/temp</swaggerDirectory>
            <swaggerApiReader>com.github.kongchen.swagger.docgen.reader.SpringMvcApiReader
            </swaggerApiReader>
            <swaggerFileName>internal-swagger</swaggerFileName>
         </apiSource>
      </apiSources>
   </configuration>
   <executions>
      <execution>
         <configuration>
            <apiSources>
               <apiSource>
                  <locations>
                     <location>com.wmock.info</location>
                  </locations>
                  <swaggerFileName>internal-swagger</swaggerFileName>
               </apiSource>
            </apiSources>
         </configuration>
         <id>internal-generation</id>
         <phase>compile</phase>
         <goals>
            <goal>generate</goal>
         </goals>
      </execution>
   </executions>
</plugin>

SWAGGER CONFIG

• Create swagger config based on swagger2

• If you need URL redirection, it is advised to create a controller as below: 

@Controller
public class SwaggerController {

    @RequestMapping("/swagger")
    public String greeting() {
        return "redirect:/swagger-ui.html";
    }

}

CONTROLLER

• There are no fundamental changes needed in the controller. Here is an example.,

RUNNER

• Cmd to execute Spring MVC application; while the Swagger2 doc gets generated with the updated controller content

mvn clean spring-boot:run

• Open either one of these URLs that redirects you to the swagger ui

http://localhost:8081/swagger
http://localhost:8081/swagger-ui.html

Reference:

https://github.com/prashanth-sams/wiremock-springboot-mvc-swagger2/