Springfox global response header

Question

In my spring boot rest API, I'm sending back a unique request id header "x-request-id" for every response (irrespective of the method) for every endpoint. I can add this using something like this:

@ApiResponses(value = { 
    @ApiResponse(
            code = 200, 
            message = "Successful status response", 
            responseHeaders = {
                    @ResponseHeader(
                            name = "x-request-id", 
                            description = "auto generated unique request id", 
                            response = String.class)})
})

This works fine and I can see it in the Swagger UI. However, doing this for every endpoint is a tedious + maintenance problem. I'm looking to do this globally but the Springfox documentation only shows about global response message using .globalResponseMessage option - I can't find anything for global response headers.

Answer 1

Ended up creating an annotation to handle this:

package com.abc.xyz.api.docs.annotations;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import io.swagger.annotations.ApiResponse;
import io.swagger.annotations.ApiResponses;
import io.swagger.annotations.ResponseHeader;

import com.abc.xyz.api.constants.ApiConstants;

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@ApiResponses(value = { 
    @ApiResponse(
            code = 200, 
            message = "Successful status response",
            responseHeaders = {
                    @ResponseHeader(
                            name = ApiConstants.REQUESTIDHEADER,
                            description = ApiConstants.REQUESTIDDESCRIPTION, 
                            response = String.class)}),
    @ApiResponse(
            code = 401, 
            message = "Successful status response",
            responseHeaders = {
                    @ResponseHeader(
                            name = ApiConstants.REQUESTIDHEADER,
                            description = ApiConstants.REQUESTIDDESCRIPTION, 
                            response = String.class)}),
    @ApiResponse(
            code = 403, 
            message = "Successful status response",
            responseHeaders = {
                    @ResponseHeader(
                            name = ApiConstants.REQUESTIDHEADER,
                            description = ApiConstants.REQUESTIDDESCRIPTION, 
                            response = String.class)}),
    @ApiResponse(
            code = 404, 
            message = "Successful status response",
            responseHeaders = {
                    @ResponseHeader(
                            name = ApiConstants.REQUESTIDHEADER,
                            description = ApiConstants.REQUESTIDDESCRIPTION, 
                            response = String.class)}),
    }
)
public @interface RequestIdMethod {};

With this, I can add this as a marker annotation in front of my methods:

@RequestMapping(value = "/heartbeat", method = RequestMethod.GET)
@RequestIdMethod
public Heartbeat checkHeartbeat() {
    return new Heartbeat(status);
}

It is not great because I need to repeat the entire @ApiResponse annotation block for every http return code (obviously there could be other return codes but I only covered the default codes shown by Springfox). Would have been better if there was a way to parameterize the entire @ApiResponse block.