Swagger plugin for dynamic allowed values

ParameterDynamicAllowedValuesBuilder.java

package mydomain.swagger;

import mydomain.repo.AttributeMetadataRepo;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.base.Optional;
import io.swagger.annotations.ApiParam;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spi.service.ParameterBuilderPlugin;
import springfox.documentation.spi.service.contexts.ParameterContext;
import springfox.documentation.swagger.common.SwaggerPluginSupport;


/**
 * Handles parameters with allowed value list that is dynamically retrieved from database. To activate this plugin, set
 * the allowableValues property of the @ApiParam annotation to "dynamic[whatever]".
 */
@Component
@Order(SwaggerPluginSupport.SWAGGER_PLUGIN_ORDER + 1)
public class ParameterDynamicAllowedValuesBuilder implements ParameterBuilderPlugin {

    private final AttributeMetadataRepo repo;
    private final ObjectMapper mapper;

    @Autowired
    public ParameterDynamicAllowedValuesBuilder(AttributeMetadataRepo repo, ObjectMapper mapper) {
        this.repo = repo;
        this.mapper = mapper;
    }

    @Override
    public void apply(ParameterContext context) {
        @SuppressWarnings("Guava") final Optional<ApiParam> apiParam =
                context.resolvedMethodParameter().findAnnotation(ApiParam.class);

        if (apiParam.isPresent()) {
            final String allowableValuesString = apiParam.get().allowableValues();
            if ("dynamic[whatever]".equals(allowableValuesString)) {
                context.parameterBuilder().allowableValues(new DynamicAllowableValues(repo));
            }
        }
    }

    @Override
    public boolean supports(DocumentationType delimiter) {
        return SwaggerPluginSupport.pluginDoesApply(delimiter);
    }
}

I needed to set the parameterType in parmeterBuilder to query as well for it to work as intended.