apache/maven · error · XMLStreamException

Unable to parse element '{}', must be a short integer

Error message

Unable to parse element '{}', must be a short integer

What it means

Thrown by the Modello-generated StAX reader (template src/mdo/reader.vm) when a model XML field typed as short cannot be parsed by Short.valueOf(String). getShortValue in strict mode converts the NumberFormatException into a javax.xml.stream.XMLStreamException ('must be a short integer'); non-strict mode returns 0. Only models that declare short fields can trigger it.

Source

Thrown at src/mdo/reader.vm:1022

    /**
     * Method getShortValue.
     *
     * @param s a s object.
     * @param strict a strict object.
     * @param parser a parser object.
     * @param attribute a attribute object.
     * @throws XMLStreamException XMLStreamException if
     * any.
     * @return short
     */
    private short getShortValue(String s, String attribute, XMLStreamReader parser, boolean strict)
            throws XMLStreamException {
        if (s != null) {
            try {
                return Short.valueOf(s).shortValue();
            } catch (NumberFormatException nfe) {
                if (strict) {
                    throw new XMLStreamException("Unable to parse element '" + attribute + "', must be a short integer", parser.getLocation(), nfe);
                }
            }
        }
        return 0;
    } //-- short getShortValue(String, String, XMLStreamReader, boolean)

    /**
     * Method getTrimmedValue.
     *
     * @param s a s object.
     * @return String
     */
    private String getTrimmedValue(String s) {
        if (s != null) {
            s = s.trim();
        }
        return s;
    } //-- String getTrimmedValue(String)

View on GitHub (pinned to e4093d4e12)

Solutions

1. Set the offending value within the short range (-32768..32767).
2. If the value legitimately exceeds short range, move to an int/long field in the model and regenerate the reader.
3. Use strict=false when defaulting to 0 is acceptable.
4. Validate config values with a schema or unit test before writing the file.

Example fix

<!-- before -->
<port>99999</port>
<!-- after -->
<port>32767</port>

static boolean inShortRange(int v) { return v >= Short.MIN_VALUE && v <= Short.MAX_VALUE; }

try {
    reader.read(in, true);
} catch (XMLStreamException e) {
    // message names field; fix data or downgrade to strict=false
}

When it happens

Trigger: Strict read of a model XML where a short field contains text like 'abc', is empty, or exceeds -32768..32767 (e.g. a port or count field set to 99999).

Common situations: Port/count fields overflowing after config changes; hand-edited files with typos; producers not validating ranges on write.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• Unable to parse element '{}', must be a byte
• Unable to parse element '{}', must be a floating point numbe
• Unable to parse element '{}', must be an integer
• Unable to parse element '{}', must be a long integer
• Expected root element '${rootTag}' but found '{}'

AI-assisted analysis of apache/maven@e4093d4e12 (2026-08-21). Data as JSON: /api/errors/b21facc78b82df02. Report an issue: GitHub.