Setting up Swagger 3 With Spring Boot

Documentation is a very important part of any restful API, Swagger had made it easy for developers to get a neat documentation for their API endpoints that is readable for both humans and machines only with a few steps. Swagger lists all API endpoints with detailed information about them like description, parameters and output schema in JSON format while Swagger-UI provides a styled interface with the ability to test the endpoints.

Swagger 2 still works with Spring Boot 2, but it doesn’t integrate well and you might encounter some inconvenience, therefor, it’s better to use swagger 3 with Spring Boot 2.

So let’s jump right in to the simple steps:

1. Adding dependencies

Add the 3rd version springfox-boot-starter and springfox-swagger-ui to pom.xml for maven project

<dependency>
   <groupId>io.springfox</groupId>
   <artifactId>springfox-boot-starter</artifactId>
   <version>3.0.0</version>
</dependency>
<dependency>
   <groupId>io.springfox</groupId>
   <artifactId>springfox-swagger-ui</artifactId>
   <version>3.0.0</version>
</dependency>

or to gradle file for gradle project

repositories {
    jcenter()
}

dependencies {
    implementation "io.springfox:springfox-boot-starter:3.0.0"
    compile "io.springfox:springfox-swagger-ui:3.0.0"
}

2. Configuration

Swagger configuration is done using Docket Bean, below is a simple configuration to integrate Swagger with Spring Boot, you can add more customization to your documentation in the Docket Bean, also you may create more than one Docket Bean.

@Configuration
public class SpringFoxConfig {

    @Bean
    public Docket api() {
        return new Docket(DocumentationType.SWAGGER_2)
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build();
    }
}

3. Verification

Verification URI has been changed from what used to be in version 2, for JSON output http… your-app-root/v2/api-docs , for a human readable documentation provided by swagger-UI use http..your-app-root/swagger-ui/index.html

Resource: https://springfox.github.io/springfox/docs/current/