alibaba/nacos · error · IllegalArgumentException

Param '{}' is required.

Error message

Param '{}' is required.

What it means

Error "Param '{}' is required." thrown in alibaba/nacos.

Source

Thrown at core/src/main/java/com/alibaba/nacos/core/utils/WebUtils.java:72

    private static final String TMP_SUFFIX = ".tmp";
    
    public static final String X_REAL_IP = "X-Real-IP";
    
    public static final String X_FORWARDED_FOR = "X-Forwarded-For";
    
    private static final String X_FORWARDED_FOR_SPLIT_SYMBOL = ",";
    
    /**
     * get target value from parameterMap, if not found will throw {@link IllegalArgumentException}.
     *
     * @param req {@link HttpServletRequest}
     * @param key key
     * @return value
     */
    public static String required(final HttpServletRequest req, final String key) {
        String value = req.getParameter(key);
        if (StringUtils.isEmpty(value)) {
            throw new IllegalArgumentException("Param '" + key + "' is required.");
        }
        String encoding = req.getParameter(ENCODING_KEY);
        return resolveValue(value, encoding);
    }
    
    /**
     * get target value from parameterMap, if not found will return default value.
     *
     * @param req          {@link HttpServletRequest}
     * @param key          key
     * @param defaultValue default value
     * @return value
     */
    public static String optional(final HttpServletRequest req, final String key,
        final String defaultValue) {
        String value = req.getParameter(key);
        if (StringUtils.isBlank(value)) {
            return defaultValue;

View on GitHub (pinned to 9b989acdf1)

Solutions

1. Include the required parameter in the request and retry.

When it happens

Trigger: Thrown at core/src/main/java/com/alibaba/nacos/core/utils/WebUtils.java:72 when the library encounters an invalid state.

Common situations: A required web request parameter was not provided.

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/89d659a2f51c6be5. Report an issue: GitHub.