hibernate/hibernate-orm · error · IllegalStateException

unexpected read [{}] in current processing state {}

Error message

unexpected read [{}] in current processing state {}

What it means

An unquoted token was consumed successfully, but the state machine is neither ARRAY nor OBJECT — bare literals are only legal as array elements or as an object attribute value after ':'. The message shows the token and state, e.g. 'unexpected read [a] in current processing state STARTING_OBJECT'. The two classic causes are unquoted object keys and top-level bare scalars.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/type/format/StringJsonDocumentReader.java:218

				case SEPARATOR:
					// unless we are processing an array, following SEPARATOR that will a key
					break;
				case OTHER:
					// here we are in front of a boolean, a null or a numeric value.
					// if none of these cases we're going to raise IllegalStateException
					// put back what we've read
					moveBufferPosition(-1);
					final int valueSize = consumeNonStringValue();
					if (valueSize == -1) {
						throw new IllegalStateException( "Unrecognized marker: " + StringJsonDocumentMarker.markerOf(
								this.jsonString.charAt( this.position )));
					}
					switch ( this.processingStates.getCurrent() ) {
						case ARRAY:
						case OBJECT:
							return getUnquotedValueType(this.jsonString.charAt( this.jsonValueStart));
						default:
							throw new IllegalStateException( "unexpected read ["+
															this.jsonString.substring( this.jsonValueStart,this.jsonValueEnd )+
															"] in current processing state " +
															this.processingStates.getCurrent() );
					}
				default: {
					throw new IllegalStateException( "unexpected marker ["+
													marker +
													"] at position " + this.position );
				}
			}
		}
		throw new IllegalStateException( "unexpected end of JSON ["+
										this.jsonString.substring( this.jsonValueStart,this.jsonValueEnd )+
										"] in current processing state " +
										this.processingStates.getCurrent() );
	}

	/**

View on GitHub (pinned to fad1729dce)

Solutions

1. Fix the stored document to strict JSON: quoted keys ({"a":1}) and object/array roots
2. Make the producing system emit strict JSON (use a serializer, not string concatenation)
3. Pre-validate on write with a strict parser
4. Catch IllegalStateException around reads to identify and migrate offending rows

Example fix

-- before: unquoted key (JavaScript-style object literal)
UPDATE entity_table SET json_col = '{name:"Ada"}';
-- after: strict JSON
UPDATE entity_table SET json_col = '{"name":"Ada"}';

static void assertStrictJsonObject(String candidate) {
    com.fasterxml.jackson.databind.ObjectMapper m =
            new com.fasterxml.jackson.databind.ObjectMapper()
                    .enable(com.fasterxml.jackson.core.JsonParser.Feature.STRICT_DUPLICATE_DETECTION);
    try {
        m.readTree(candidate);
    } catch (Exception e) {
        throw new IllegalArgumentException("Not strict JSON (unquoted keys? bare scalar root?): " + e.getMessage(), e);
    }
}

try {
    entity = session.find(MyEntity.class, id);
} catch (IllegalStateException e) {
    if (e.getMessage() != null && e.getMessage().startsWith("unexpected read [")) {
        // stored document uses relaxed JSON (e.g. unquoted keys) - repair required
        throw new DataQualityException("Column contains non-strict JSON", e);
    }
    throw e;
}

When it happens

Trigger: next() reading an OTHER token while state is STARTING_OBJECT (unquoted key like {a:1} — JSON requires keys in quotes), NONE (bare top-level scalar document like 42 or true), or OBJECT_KEY_NAME/ENDING_* states where a quoted key or structural token is required.

Common situations: Hand-written 'relaxed JSON' with unquoted keys or single quotes (JavaScript object literals) pasted into a column; systems emitting non-strict JSON; storing a plain number/string directly in a JSON column without wrapping it in an object or array.

Related errors

• unexpected quote read in current processing state {}
• Unexpected JsonProcessingState {}
• Unrecognized marker: {}
• unexpected end of JSON [{}] in current processing state {}
• Can't find ending quote of key name

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/37af84a3d103d984. Report an issue: GitHub.