* error handling, and validation in web API context.
 */
public final class WebApiUtil {

    /**
     * Request attribute key for storing web API exceptions.
     */
    private static final String WEB_API_EXCEPTION = "webApiException";

    /**
     * Private constructor to prevent instantiation.
     */
    private WebApiUtil() {
    }

    /**
     * Sets an object in the current request attributes.

            WebApiUtil.setError(400, "Bad Request");
            WebApiUtil.setError(401, "Unauthorized");
            WebApiUtil.setError(403, "Forbidden");
            WebApiUtil.setError(404, "Not Found");
            WebApiUtil.setError(500, "Internal Server Error");
            WebApiUtil.setError(502, "Bad Gateway");
            WebApiUtil.setError(503, "Service Unavailable");
        } catch (Exception e) {