hibernate/hibernate-orm · error · NoSuchElementException

No more item in JSON document

Error message

No more item in JSON document

What it means

OsonDocumentReader wraps Oracle's OracleJsonParser for binary OSON documents. next() defensively re-checks parser.hasNext() and throws NoSuchElementException 'No more item in JSON document' when the caller drains past the end - in Hibernate-driven reads this means the embeddable mapping's structure expectation (driven by getAdapter) wants more events than the stored document actually contains.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/type/format/OsonDocumentReader.java:48

	private Object currentValue;

	/**
	 * Creates a new <code>OsonDocumentReader</code>  on top of a <code>OracleJsonParser</code>
	 * @param parser the parser
	 */
	public OsonDocumentReader(OracleJsonParser parser) {
		this.parser = parser;
	}

	@Override
	public boolean hasNext() {
		return this.parser.hasNext();
	}

	@Override
	public JsonDocumentItemType next() {
		if (!this.parser.hasNext())
			throw new NoSuchElementException("No more item in JSON document");
		OracleJsonParser.Event evt = this.parser.next();
		currentKeyName = null;
		currentValue = null;
		switch (evt) {
			case START_OBJECT:
				return JsonDocumentItemType.OBJECT_START;
			case END_OBJECT:
				return JsonDocumentItemType.OBJECT_END;
			case START_ARRAY:
				return JsonDocumentItemType.ARRAY_START;
			case END_ARRAY:
				return JsonDocumentItemType.ARRAY_END;
			case KEY_NAME:
				currentKeyName = this.parser.getString();
				return JsonDocumentItemType.VALUE_KEY;
			case VALUE_TIMESTAMPTZ:
				currentValue = this.parser.getOffsetDateTime();
				return JsonDocumentItemType.VALUE;

View on GitHub (pinned to fad1729dce)

Solutions

1. When driving the reader directly, guard every next() with hasNext()
2. Validate the stored documents (Oracle IS JSON check / jsonb validation, or a Jackson parse) and repair malformed rows
3. Align the embeddable mapping with the actual document structure - missing keys are fine (nulls), but structural tokens must match
4. Catch NoSuchElementException during aggregate reads and rethrow as a data-quality error identifying the row

Example fix

// before
while (true) {
    JsonDocumentItemType item = reader.next(); // throws 'No more item in JSON document' at end
}

// after
while (reader.hasNext()) {
    JsonDocumentItemType item = reader.next();
}

while (reader.hasNext()) { // guard every next() when driving the reader directly
    JsonDocumentItemType item = reader.next();
}

try {
    MyAgg agg = session.find(MyEntity.class, id).getAgg();
} catch (NoSuchElementException e) {
    throw new DataIntegrityViolationException("Truncated/malformed JSON document in row " + id, e);
}

When it happens

Trigger: Reading an Oracle JSON aggregate column whose stored document is truncated or shaped differently from the mapping (fewer object/array entries than the embeddable expects), so the adapter calls next() after the parser is exhausted; also direct API misuse (next() without hasNext()).

Common situations: Corrupt or hand-edited JSON/OSON data; documents written by other services with a different schema version; mapping changes across deployments; Oracle OSON round-trips with mixed tooling.

Related errors

• Unsupportd target type
• Unsupportd source type
• Unknown OSON event: {}
• no object key available
• Unsupported numeric type: {}

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/a1771cbdc401b8bc. Report an issue: GitHub.