spring-projects/spring-ai · error · IllegalArgumentException

Invalid date type:

Error message

Invalid date type: 

What it means

normalizeDateString normalizes date values in filter expressions to java.util.Date using ISO_DATE_FORMATTER. If the text cannot be parsed as an ISO date it throws IllegalArgumentException("Invalid date type: " + text). This validates that date-typed filter values are real ISO-formatted dates.

Solutions

1. Use ISO-8601 date format (yyyy-MM-dd or full ISO date-time) in filter date values, e.g. "createdAt > 2024-01-15"
2. Pre-parse your date in application code with LocalDate.parse(..., DateTimeFormatter.ISO_LOCAL_DATE) to validate before building the filter
3. Catch IllegalArgumentException and prompt the user with the expected ISO format

Example fix

// before
parser.parse("createdAt > 01/15/2024");
// after
parser.parse("createdAt > 2024-01-15");

try { LocalDate.parse(dateText, DateTimeFormatter.ISO_LOCAL_DATE); }
catch (DateTimeParseException e) { throw new IllegalArgumentException("Use ISO date: yyyy-MM-dd"); }

try { filter = parser.parse(text); }
catch (IllegalArgumentException e) { throw new IllegalArgumentException("Invalid date in filter, expected ISO format: " + e.getMessage(), e); }

When it happens

Trigger: Using a date string value in a filter (e.g. "createdAt > <date>") where the value text reaching normalizeDateString (via doValue) is not ISO format — e.g. "01/15/2024", "Jan 15 2024", or an impossible date like "2024-13-45" — causing DateTimeParseException.

Common situations: US-style date formats in filter strings; locale-specific dates; user-supplied dates passed straight into filter expressions; typos like 2024-1-5 without zero padding.

Related errors

• Cannot compare values of incompatible types
• Cannot compare values of incompatible types
• Cannot compare values of types
• Cannot compare values of types
• Expected a Key operand but got:

AI-assisted analysis of spring-projects/spring-ai@98a7beda4f (2026-09-11). Data as JSON: /api/errors/c26f809ddb02cdf2. Report an issue: GitHub.

Appendix: source

Thrown at spring-ai-vector-store/src/main/java/org/springframework/ai/vectorstore/filter/converter/AbstractFilterExpressionConverter.java:185

		}
	}

	/**
	 * If the value is a string matching the ISO date pattern, parse and return as
	 * {@link Date} so that all converters that handle {@code Date} automatically support
	 * date strings. Otherwise return the value unchanged.
	 * @param value the value (possibly a date string)
	 * @return the value, or a {@code Date} if the value was a parseable date string
	 */
	protected static Object normalizeDateString(Object value) {
		if (!(value instanceof String text) || !ISO_DATE_PATTERN.matcher(text).matches()) {
			return value;
		}
		try {
			return Date.from(Instant.from(ISO_DATE_FORMATTER.parse(text)));
		}
		catch (DateTimeParseException e) {
			throw new IllegalArgumentException("Invalid date type: " + text, e);
		}
	}

	/**
	 * Convert the given single value into a string representation and append it to the
	 * context. This method handles all value types including String, Number, Boolean,
	 * Date, etc.
	 * <p>
	 * For convenience, implementations can use the provided static helper methods such as
	 * {@link #emitJsonValue(Object, StringBuilder)} for JSON-based filters,
	 * {@link #emitLuceneString(String, StringBuilder)} for Lucene-based filters, or
	 * implement their own format-specific escaping logic as needed.
	 * @param value the value to convert
	 * @param context the context to append the string representation to
	 */
	protected abstract void doSingleValue(Object value, StringBuilder context);

	/**

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