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Global Header in Swagger-Ui Spring-Boot

Suraj
Happy to Develop
Updated on ・2 min read

This article is about adding custom headers in all Apis globally without writing in each API method.

Why do we need it?

There are cases where we need some header value from consumers to validate the request.

Example - Basic-Auth-Token, which can be validated from a servlet filter, so we don’t need to add it as a header parameter in each API method.

But, on exposing the API, we would want that the Basic-Auth-Token parameter reflects in each API under Swagger-UI to make testing easier.

Like in below image

So, let's get on how to do it
  • The first step would be to create a docket bean as below
  @Bean
  public Docket docket() {
    return new Docket(DocumentationType.SWAGGER_2)
        .forCodeGeneration(true)
        .globalOperationParameters(globalParameterList()) 
// ^ here we are passing the global paramters to inlcude in swagger-ui
        .select()
        .apis( RequestHandlerSelectors.withClassAnnotation(RestController.class))
        .paths(PathSelectors.any())
        .build();
  }
Make sure that @EnableSwagger2 is added in the Application file
  • Now, let's add global parameters that we need to pass in above docket bean
  private List<Parameter> globalParameterList() {

    val authTokenHeader =
        new ParameterBuilder()
            .name("AUTH-TOKEN") // name of the header
            .modelRef(new ModelRef("string")) // data-type of the header
            .required(true) // required/optional
            .parameterType("header") // for query-param, this value can be 'query'
            .description("Basic Auth Token")
            .build();

    return Collections.singletonList(authTokenHeader);
  }
  • Add a RequestFilter to log the incoming request header that we just added.
@Component
@Slf4j
public class RequestFilter implements Filter {

  @Override
  public void doFilter(
      ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
      throws IOException, ServletException {
    log.info(
        "Value of AUTH-TOKEN  -> {}",
        ((HttpServletRequest) servletRequest).getHeader("AUTH-TOKEN"));
    filterChain.doFilter(servletRequest, servletResponse);
  }
}
  • Finally, a simple hello-world controller to test what we just made.
@RestController
@RequestMapping("/hello-world")
public class HelloWorldController {

  @GetMapping
  public ResponseEntity sayHello() { // No header needed here - that got covered in docket
    return ResponseEntity.ok("Hello There!!!");
  }
}
How the output will look like

Sample Project can be found at

GitHub logo s2agrahari / swagger-global-header-spring-boot

Global Header in Swagger without writing in Controller

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