Extension mapping

since 2024.1

This is part of annotation mapping. See Annotation mapping that shows more details about the annotation mapping format.

Apart from the annotation mapping by an OpenAPI type, openapi-processor can use x- tension properties in the OpenAPI to add additional annotations to a schema property.

Here is a simple schema that has x- tensions on the bar property.

openapi: 3.1.0
# ...
      type: object
          type: string
          x-foo: single
            - listA
            - listB

In general openapi-processor will ignore the x- tension properties unless we map the x- tensions/values to annotations like this:

openapi-processor-mapping: v7
  # ...

    x-foo: single @ io.oap.FooA(value = "any")   (1)
      - listA @ io.oap.FooB (2)
      - listB @ io.oap.FooC
openapi-processor will only recognize strings values of an extension. It will ignore any other type.

The mapping allows two variations:

1 in case the x- tension property has only a single value we can directly map that value to an annotation.
2 in case the x- tension property has a list of values we can map each value to a different annotation.

With this mapping the generated Dto class will have the additional annotations on the property.

package generated.model;

import com.fasterxml.jackson.annotation.JsonProperty;
import generated.support.Generated;
import io.oap.FooA;
import io.oap.FooB;
import io.oap.FooC;

@Generated(value = "openapi-processor-core")
public class Foo {

    @FooA(value = "any")
    private String bar;

    public String getBar() {
        return bar;

    public void setBar(String bar) {
        this.bar = bar;