alibaba/Sentinel · error · IllegalArgumentException

${name} is null or empty

Error message

${name} is null or empty

What it means

EagleEyeCoreUtils.checkNotNullEmpty(value, name) is the eagleeye core precondition helper: it throws IllegalArgumentException('<name> is null or empty') when the value is null, empty, or whitespace-only. All eagleeye logger builders (file paths, logger names, etc.) funnel through it, so this error marks a required string argument missing or blank.

Source

Thrown at sentinel-core/src/main/java/com/alibaba/csp/sentinel/eagleeye/EagleEyeCoreUtils.java:48

    public static final String[] EMPTY_STRING_ARRAY = new String[0];

    public static boolean isBlank(String str) {
        int strLen;
        if (str == null || (strLen = str.length()) == 0) {
            return true;
        }
        for (int i = 0; i < strLen; i++) {
            if ((!Character.isWhitespace(str.charAt(i)))) {
                return false;
            }
        }
        return true;
    }

    public static String checkNotNullEmpty(String value, String name) throws IllegalArgumentException {
        if (isBlank(value)) {
            throw new IllegalArgumentException(name + " is null or empty");
        }
        return value;
    }

    public static <T> T checkNotNull(T value, String name) throws IllegalArgumentException {
        if (value == null) {
            throw new IllegalArgumentException(name + " is null");
        }
        return value;
    }

    public static <T> T defaultIfNull(T value, T defaultValue) {
        return (value == null) ? defaultValue : value;
    }

    public static boolean isNotBlank(String str) {
        return !isBlank(str);
    }

View on GitHub (pinned to a3f40ba8e9)

Solutions

1. Supply a non-blank value, e.g. a concrete path under a known log dir
2. Default the variable first: String p = (path == null || path.trim().isEmpty()) ? "/var/log/app" : path;
3. Check for misspelled/unloaded config keys feeding the argument at initialization time

Example fix

// before
builder.configLogFilePath(System.getProperty("eagleeye.log.dir")); // null if unset

// after
String dir = System.getProperty("eagleeye.log.dir", "/tmp");
builder.configLogFilePath(dir + "/eagleeye.log");

String value = Objects.requireNonNullElse(source, "").trim();
if (value.isEmpty()) {
    value = "/default/path"; // or reject explicitly
}
EagleEyeCoreUtils.checkNotNullEmpty(value, "filePath");

When it happens

Trigger: Calling checkNotNullEmpty("", "filePath") or checkNotNullEmpty(null, "loggerName"); indirectly via BaseLoggerBuilder.configLogFilePath("") or other builder methods that validate their arguments with this helper.

Common situations: Building an eagleeye/Sentinel log path from a variable that is null because a config key was misspelled or not yet loaded at static-init time; tests passing empty strings; path properties with only whitespace.

Related errors

• Invalid maxFileSizeMB
• ${name} is null
• keys empty or null: ${keys}
• keys empty or null
• Max entry count should be at least 1:

AI-assisted analysis of alibaba/Sentinel@a3f40ba8e9 (2026-08-14). Data as JSON: /api/errors/b9669109bdb3e79a. Report an issue: GitHub.