hibernate/hibernate-orm · error · IllegalStateException

no object key available

Error message

no object key available

What it means

OsonDocumentReader.getObjectKeyName() returns the current key name only right after the parser produced a KEY_NAME event (mapped to JsonDocumentItemType.VALUE_KEY): next() resets currentKeyName to null and only the KEY_NAME branch sets it. Calling the accessor at any other position in the iteration throws IllegalStateException 'no object key available'.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/type/format/OsonDocumentReader.java:109

				return JsonDocumentItemType.VALUE;
			case VALUE_DOUBLE:
				currentValue = this.parser.getDouble();
				return JsonDocumentItemType.VALUE;
			case VALUE_FLOAT:
				currentValue = this.parser.getFloat();
				return JsonDocumentItemType.VALUE;
			case VALUE_BINARY:
				currentValue = this.parser.getBytes();
				return JsonDocumentItemType.VALUE;
			default :
				throw new IllegalStateException( "Unknown OSON event: " + evt );
		}
	}

	@Override
	public String getObjectKeyName() {
		if (currentKeyName == null)
			throw new IllegalStateException("no object key available");
		return currentKeyName;
	}

	@Override
	public String getStringValue() {
		return (String)currentValue;
	}

	@Override
	public BigDecimal getBigDecimalValue() {
		return (BigDecimal)currentValue;
	}

	@Override
	public BigInteger getBigIntegerValue() {
		return ((BigDecimal)currentValue).toBigInteger();
	}

View on GitHub (pinned to fad1729dce)

Solutions

1. Only call getObjectKeyName() immediately after next() returned the object-key item type
2. Track the last returned JsonDocumentItemType in your loop and gate key/value accessors on it
3. Read payloads via the typed getters (getStringValue/getBigDecimalValue/...) only after VALUE items

Example fix

// before
reader.next();
String key = reader.getObjectKeyName(); // throws if last item was not a key

// after
if (reader.next() == JsonDocumentItemType.VALUE_KEY) {
    String key = reader.getObjectKeyName();
}

JsonDocumentItemType last = null;
while (reader.hasNext()) {
    last = reader.next();
    if (last == JsonDocumentItemType.VALUE_KEY) {
        String key = reader.getObjectKeyName(); // only valid here
    }
}

When it happens

Trigger: Calling getObjectKeyName() when the last next() returned anything other than the key item type - e.g. while iterating array elements, before the first next(), or after consuming the key and its value.

Common situations: Custom adapters or integration code driving JsonDocumentReader; porting Jackson-style code where field names are always available; test harnesses that call accessors eagerly.

Related errors

• Unsupportd target type
• Unsupportd source type
• No more item in JSON document
• Unknown OSON event: {}
• Unsupported numeric type: {}

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/305754aba9507b3a. Report an issue: GitHub.