Result mapping

Standard

A ResponseEntity<> allows an endpoint implementation full control of the response.

Here is a super simple example:

Java code

public ResponseEntity<String> getFoo() {
    return ResponseEntity.ok("foo");
}

To enable a result wrapper set the result mapping in the mapping YAML to a fully qualified java type.

mapping

map:
  result: org.springframework.http.ResponseEntity

The processor expects that it takes a single generic parameter.

Depending on the number of defined response content types the parameter of the ResponseEntity<> will be either the java type or the unknown type.

responses ResponseEntity<>

responses	ResponseEntity<>
one	`ResponseEntity<java type>`
multiple	`ResponseEntity<?>`

one

ResponseEntity<java type>

multiple

ResponseEntity<?>

plain result type

since 2025.5

The standard result mapping requires a generic wrapper type, like ResponseEntity<>. To map a non-generic type as return type the result mapping accepts an arrow mapping:

plain ⇒ {target type}

which means, instead of the plain schema described in the OpenAPI response, use the target type as endpoint return type.

mapping.yaml

openapi-processor-mapping: v15

options:
  package-name: io.openapiprocessor.generated

map:
  paths:
    /foo:
       # new, mapping of plain replacement type
       result: plain => org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody

Limit to Endpoint

The result mapping works as endpoint-specific mapping too. That way it is possible to use the ResponseEntity<> only on single endpoints.

So a mapping like this:

mapping

map:
  /foo:
    result: org.springframework.http.ResponseEntity

will only wrap the result of the endpoint /foo.

In case of global type mapping

mapping.yaml fragment

map:
  result: org.springframework.http.ResponseEntity

that should not apply to a specific endpoint it is possible to clear the global mapping by setting result to plain:

mapping

map:
  result: org.springframework.http.ResponseEntity

  paths:
    /foo:
      # clear the top level "result" property, "plain" means no wrapper
      result: plain