An example of OpenAPISpecFilter using CDI

CdiDelegatedOpenAPISpecFilter.java

package com.example;

import io.swagger.v3.core.filter.OpenAPISpecFilter;
import io.swagger.v3.core.model.ApiDescription;
import io.swagger.v3.oas.models.OpenAPI;
import io.swagger.v3.oas.models.Operation;
import io.swagger.v3.oas.models.PathItem;
import io.swagger.v3.oas.models.media.Schema;
import io.swagger.v3.oas.models.parameters.Parameter;
import io.swagger.v3.oas.models.parameters.RequestBody;
import io.swagger.v3.oas.models.responses.ApiResponse;

import javax.enterprise.inject.spi.Bean;
import javax.enterprise.inject.spi.BeanManager;
import javax.enterprise.inject.spi.CDI;

import java.util.List;
import java.util.Map;
import java.util.Optional;

public class CdiDelegatedOpenAPISpecFilter implements OpenAPISpecFilter {
    private OpenAPISpecFilter openAPISpecFilter;

    @SuppressWarnings("unchecked")
    private OpenAPISpecFilter openAPISpecFilter() {
        if (openAPISpecFilter == null) {
            BeanManager beanManager = CDI.current().getBeanManager();
            Bean<OpenAPISpecFilter> bean = (Bean<OpenAPISpecFilter>)beanManager.resolve(beanManager.getBeans(OpenAPISpecFilter.class));

            openAPISpecFilter = (OpenAPISpecFilter)beanManager.getReference(bean, bean.getBeanClass(), beanManager.createCreationalContext(bean));
        }

        return openAPISpecFilter;
    }

    @Override
    public Optional<OpenAPI> filterOpenAPI(OpenAPI openAPI, Map<String, List<String>> params, Map<String, String> cookies, Map<String, List<String>> headers) {
        return openAPISpecFilter().filterOpenAPI(openAPI, params, cookies, headers);
    }

    @Override
    public Optional<PathItem> filterPathItem(PathItem pathItem, ApiDescription api, Map<String, List<String>> params, Map<String, String> cookies, Map<String, List<String>> headers) {
        return openAPISpecFilter().filterPathItem(pathItem, api, params, cookies, headers);
    }

    @Override
    public Optional<Operation> filterOperation(Operation operation, ApiDescription api, Map<String, List<String>> params, Map<String, String> cookies, Map<String, List<String>> headers) {
        return openAPISpecFilter().filterOperation(operation, api, params, cookies, headers);
    }

    @Override
    public Optional<Parameter> filterParameter(Parameter parameter, Operation operation, ApiDescription api, Map<String, List<String>> params, Map<String, String> cookies, Map<String, List<String>> headers) {
        return openAPISpecFilter().filterParameter(parameter, operation, api, params, cookies, headers);
    }

    @Override
    public Optional<RequestBody> filterRequestBody(RequestBody requestBody, Operation operation, ApiDescription api, Map<String, List<String>> params, Map<String, String> cookies, Map<String, List<String>> headers) {
        return openAPISpecFilter().filterRequestBody(requestBody, operation, api, params, cookies, headers);
    }

    @Override
    public Optional<ApiResponse> filterResponse(ApiResponse response, Operation operation, ApiDescription api, Map<String, List<String>> params, Map<String, String> cookies, Map<String, List<String>> headers) {
        return openAPISpecFilter().filterResponse(response, operation, api, params, cookies, headers);
    }

    @Override
    public Optional<Schema> filterSchema(Schema schema, Map<String, List<String>> params, Map<String, String> cookies, Map<String, List<String>> headers) {
        return openAPISpecFilter().filterSchema(schema, params, cookies, headers);
    }

    @Override
    public Optional<Schema> filterSchemaProperty(Schema property, Schema schema, String propName, Map<String, List<String>> params, Map<String, String> cookies, Map<String, List<String>> headers) {
        return openAPISpecFilter().filterSchemaProperty(property, schema, propName, params, cookies, headers);
    }

    @Override
    public boolean isRemovingUnreferencedDefinitions() {
        return openAPISpecFilter().isRemovingUnreferencedDefinitions();
    }
}

See swagger-api/swagger-core#3522