quarkusio/quarkus · error · IllegalArgumentException

`pattern` must not be `null`

Error message

`pattern` must not be `null`

What it means

ScanArgs.match() is a fluent builder for the Redis SCAN MATCH pattern argument. The library validates its inputs eagerly and throws IllegalArgumentException when the pattern is null, because a null MATCH pattern cannot be encoded into the Redis command and would indicate a caller bug.

Source

Thrown at extensions/redis-client/runtime/src/main/java/io/quarkus/redis/datasource/ScanArgs.java:36

     * @return the current {@code ScanArgs}
     */
    public ScanArgs count(long count) {
        if (count <= 0) {
            throw new IllegalArgumentException("`count` must be strictly positive");
        }
        this.count = count;
        return this;
    }

    /**
     * Sets a {@code MATCH} pattern
     *
     * @param pattern the pattern, must not be {@code null}
     * @return the current {@code ScanArgs}
     */
    public ScanArgs match(String pattern) {
        if (pattern == null) {
            throw new IllegalArgumentException("`pattern` must not be `null`");
        }
        this.match = pattern;
        return this;
    }

    public List<String> toArgs() {
        List<String> args = new ArrayList<>();
        if (this.count != -1) {
            args.add("COUNT");
            args.add(Long.toString(this.count));
        }
        if (this.match != null) {
            args.add("MATCH");
            args.add(this.match);
        }
        return args;
    }
}

View on GitHub (pinned to e1c734241f)

Solutions

1. Ensure the pattern passed to match() is non-null before building ScanArgs
2. Default the pattern to "*" (match all) when no specific pattern is configured
3. If the pattern is optional, skip calling match() entirely instead of passing null

Example fix

// before
String pattern = config.pattern(); // may be null
args.match(pattern);
// after
String pattern = config.pattern();
if (pattern != null) {
    args.match(pattern);
}

if (pattern == null) { throw new IllegalArgumentException("pattern required"); }
args.match(pattern);

static boolean isValidPattern(String p) { return p != null && !p.isEmpty(); }

try { args.match(pattern); } catch (IllegalArgumentException e) { args = new ScanArgs(); /* fallback to no MATCH */ }

When it happens

Trigger: Calling ScanArgs.match(null) directly, or passing a variable that failed to initialize (e.g. a null config property or user-supplied pattern) into match() while building args for scan/keys-style commands.

Common situations: Configuration property for a scan pattern not set; a lookup map returning null for a pattern; refactoring where the pattern variable became Optional/null.

Related errors

• `timeout` must not be `null`
• `timestamp` must not be `null`
• Invalid integer encoding for a bit field type: " + bit + ".
• `bits` must be strictly positive
• Signed integers support only up to 64 bits

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/ee5c80c6d168564f. Report an issue: GitHub.