ParamUtil.java

package eu.europeana.cloud.service.mcs.rest;

import eu.europeana.cloud.common.response.ErrorInfo;
import eu.europeana.cloud.service.mcs.status.McsErrorCode;

import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Response;
import java.util.List;
import java.util.Set;

/**
 * Util for parameters.
 */
final class ParamUtil {

    /**
     * Checks if parameter value is not null. If it is, WebApplicationException is thrown with 400 HTTP code and
     * suitable message in response body indicating name of form parameter name that is required.
     *
     * @param parameterName  form parameter name
     * @param parameterValue form parameter value
     */
    static void require(String parameterName, Object parameterValue) {
        if (parameterValue == null) {
            ErrorInfo errorInfo = new ErrorInfo(McsErrorCode.OTHER.name(), parameterName + " is a required parameter");
            throw new WebApplicationException(Response.status(Response.Status.BAD_REQUEST).entity(errorInfo).build());
        }
    }

    /**
     * Checks if parameter value is present in acceptedValues list. If it isn't on the list, WebApplicationException is thrown with 400 HTTP code and
     * suitable message in response body indicating name of form parameter name that value is unsupported.
     *
     * @param parameterName  form parameter name
     * @param parameterValue form parameter value
     * @param acceptedValues white list of accepted values
     */
    static <T> void validate(String parameterName, T parameterValue, List<T> acceptedValues) {
        if (!acceptedValues.contains(parameterValue)) {
            ErrorInfo errorInfo = new ErrorInfo(McsErrorCode.OTHER.name(), parameterName + " has unsupported value");
            throw new WebApplicationException(Response.status(Response.Status.BAD_REQUEST).entity(errorInfo).build());
        }
    }


    /**
     * Checks if the tag set is valid against a set of expected allowed tags
     *
     * @param tags         set of tags
     * @param expectedTags set of expected tags
     */
    static void validateTags(Set<String> tags, Set<String> expectedTags) {
        if (!expectedTags.containsAll(tags)) {
            ErrorInfo errorInfo = new ErrorInfo(McsErrorCode.OTHER.name(), "The tags set was not validated !, The accepted tags are : " + expectedTags);
            throw new WebApplicationException(Response.status(Response.Status.BAD_REQUEST).entity(errorInfo).build());
        }
    }


    private ParamUtil() {
    }
}