Mandatory header for all API in openapi 3.0 - spring-boot

Question

I am using OpenAPI 3.0 with Spring-boot 5 and therefore have no configuration YAML. I have a header that contains the client Identification ID(This is not an authentication header). I want to make that a mandatory header param. Added below OpenAPI configuration
#Configuration
public class OpenAPIConfiguration {
#Bean
public OpenAPI customOpenAPI() {
return new OpenAPI()
.components(new Components()
.addParameters("myCustomHeader", new Parameter().in("header").schema(new StringSchema()).required(true).description("myCustomHeader").name("myCustomHeader")))
.info(new Info()
.title("My Rest Application")
.version("1.2.26"));
}
}
However, the swagger UI does not show the required param in any API. Can someone help as to what I am doing wrong?

Answer 1

Adding parameter definition to a custom OpenAPI bean will not work because the parameter won't get propagated to the operations definitions. You can achieve your goal using OperationCustomizer:
#Bean
public OperationCustomizer customize() {
return (operation, handlerMethod) -> operation.addParametersItem(
new Parameter()
.in("header")
.required(true)
.description("myCustomHeader")
.name("myCustomHeader"));
}
The OperationCustomizer interface was introduced in the springdoc-openapi 1.2.22. In previous versions you would need to use OpenApiCustomiser:
#Component
public class MyOpenApiCustomizer implements OpenApiCustomiser {
private static final List<Function<PathItem, Operation>> OPERATION_GETTERS = Arrays.asList(
PathItem::getGet, PathItem::getPost, PathItem::getDelete, PathItem::getHead,
PathItem::getOptions, PathItem::getPatch, PathItem::getPut);
private Stream<Operation> getOperations(PathItem pathItem) {
return OPERATION_GETTERS.stream()
.map(getter -> getter.apply(pathItem))
.filter(Objects::nonNull);
}
#Override
public void customise(OpenAPI openApi) {
openApi.getPaths().values().stream()
.flatMap(this::getOperations)
.forEach(this::customize);
}
private void customize(Operation operation) {
operation.addParametersItem(
new Parameter()
.in("header")
.required(true)
.description("myCustomHeader")
.name("myCustomHeader"));
}
}