Swagger UI ReST Documentation

Where SOAP gives a clear contract between the client and service, ReST services do not.  This means that the documentation is even more important to allow correct use of the service for the client.  Swagger allows the ReST endpoints to be documented as annotations within the code so that it is easier to write and maintain.

Maven Dependencies

Add the two dependencies below to use swagger and enable the 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>2.6.1</version>
    </dependency>

Spring Integration

With Spring annotation driven configuration this process is easy.  Create a class and annotate it with @Configuration so that spring uses it.  Additionally use @EnableSwagger2 to make sure that swagger is enabled.

@Configuration
@EnableSwagger2
public class SwaggerConfiguration
{
    /**
     * Add to the swagger documentation
     *
     * @return The {@link Docket} class with api information and config
     */
    @Bean
    public Docket getApiDocumentation()
    {
        return new Docket(DocumentationType.SWAGGER_2)
                .groupName("Project ReST Service")
                .apiInfo(new ApiInfoBuilder()
                        .title("My Service")
                        .description("My service which does lots of interesting things.")
                        .build())
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build();
    }
}

With spring boot the situation isn't really any different to that above accept that the @EnableSwagger2 can be put on the same class as a the @SpringBootApplication annotation or left exactly as it is above.

Swagger Annotations

In addition to the annotation to enable swagger (@EnableSwagger2) the other main annotations to use are,

@Api - this can be used on a controller to describe the overall behaviour

@ApiOperation - put this on the methods in the controller to describe what they do

@ApiParam - used to describe the particular parameter that is passed to a controller method

A full list of annotations can be found here https://github.com/swagger-api/swagger-core/wiki/Annotations-1.5.X