Custom Header Approach for Spring Boot REST API versioning

Question

I am looking to implement Versioning a REST API With Spring Boot and Swagger using Custom Headers. I went through many links like below.

https://dzone.com/articles/versioning-rest-api-with-spring-boot-and-swagger

Spring + Springfox + Header Parameters

Add a header parameter in Swagger UI documentation with Springfox

One thing look clear that my each REST endpoint has to be annotated with Custom Header headers = {"X-API-VERSION=v1"}.

Below is the my sample Rest Endpoints.

@ApiOperation(value = "Find Employees", nickname = "Find Employees")
@ApiResponses(value = { @ApiResponse(code = 200, message = "For Success as well as No Data found scenerio."),
        @ApiResponse(code = 500, message = "Internal Server Error") })
@GetMapping(value = "/employees", headers = {"X-API-VERSION=v1"})
public ResponseEntity<List<Employee>> findEmployees() {
    List<Employee> EmployeeList= employeeservice.findAllEmployees();
    return new ResponseEntity<List<Employee>>(EmployeeList,HttpStatus.OK);
}

Swagger Config changes/updates

@Configuration
@EnableSwagger2
public class SwaggerConfig{
    @Bean
    public Docket api() {
        ParameterBuilder aParameterBuilder = new ParameterBuilder();
        aParameterBuilder.name("X-API-VERSION=v1").modelRef(new ModelRef("string")).parameterType("header").required(true).build();
        List<Parameter> operationParameters = new ArrayList<>();
        operationParameters.add(aParameterBuilder.build());

        return new Docket(DocumentationType.SWAGGER_2)
                .select()
                .apis(Predicates.not(RequestHandlerSelectors.basePackage("org.springframework.boot")))
                .apis(RequestHandlerSelectors.basePackage("com.example"))
                .paths(PathSelectors.any())
                .build()
                .apiInfo(apiInfo())
                .useDefaultResponseMessages(false)
                .globalOperationParameters(operationParameters)
                .globalResponseMessage(
                        RequestMethod.GET,
                        newArrayList(new ResponseMessageBuilder().code(500).message("").build()));
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("API Management")
                .description("Sample Description")
                .termsOfServiceUrl("https://www.test.com")
                .version("0.1")
                .build();
    }
}

As per this link: https://www.springboottutorial.com/spring-boot-versioning-for-rest-services, I must pass value X-API-VERSION=v1, but when I passed that /employees/v1/error endpoint is getting called and nothing has left and no controller is getting called. How to fixed this issue ?

Answer 1

this is how this approach works.

@RestController
public class TestController {


    @RequestMapping(value = "/user")
    public String getUserDefault() {
        return "getUserDefault";
    }

    @RequestMapping(value = "/user", headers = {"X-API-VERSION=v1"})
    public String getUserV1() {
        return "getUserV1";
    }

    @RequestMapping(value = "/user", headers = {"X-API-VERSION=v2"})
    public String getUserV2() {
        return "getUserV2";
    }

}

also, you can use GetMapping instead of RequestMapping, let's test it using curl:

curl --location --request GET 'http://localhost:8080/user' --header 'X-API-VERSION: v2'

return 200 getUserV2

curl --location --request GET 'http://localhost:8080/user' --header 'X-API-VERSION: v1'

return 200 getUserV1

curl --location --request GET 'http://localhost:8080/user'

return 200 getUserDefault