apache/cassandra · error · MarshalException

Expected a long or a datestring representation of a date…

Error message

Expected a long or a datestring representation of a date value, but got a %s: %s

What it means

DateType.fromJSONObject parses a JSON value as a date: it expects a string containing either a long (epoch millis) or a datestring, parsed via TimestampType. If the JSON value is not a String (e.g. a JSON number or object), the ClassCastException is converted into this MarshalException telling you the actual Java type received.

Solutions

1. Quote the date value as a JSON string containing a long or datestring
2. Pre-convert numeric epoch millis to a string before import
3. Parse/normalize the JSON document before passing to fromJSONObject

Example fix

// before
{"created": 1735689600000}
// after
{"created": "1735689600000"}  // or "2024-01-01 00:00:00+0000"

if (!(jsonValue instanceof String)) throw new IllegalArgumentException("date JSON field must be a string: long epoch or datestring");

boolean isDateString(Object v) { return v instanceof String; }

try { DateType.instance.fromJSONObject(obj); } catch (MarshalException e) { /* retry as string, log offending field */ }

When it happens

Trigger: Calling fromJSONObject with a JSON node that is not a string, e.g. {"d": 1234567890} instead of {"d": "1234567890"} or {"d": "2015-05-01 13:00:00+0000"}.

Common situations: JSON import tooling (COPY FROM / cqlsh / custom loaders) emitting unquoted numbers or objects for date columns; scripting against cqlsh JSON input.

Related errors

• (dynamic MarshalException message)
• Expected a boolean value, but got a
• Expected a byte value, but got a
• Expected a list, but got a
• Expected a short value, but got a

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/f910653c468a9d2f. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/db/marshal/DateType.java:93

      if (source.isEmpty())
          return ByteBufferUtil.EMPTY_BYTE_BUFFER;

      return ByteBufferUtil.bytes(TimestampSerializer.dateStringToTimestamp(source));
    }

    @Override
    public Term fromJSONObject(Object parsed) throws MarshalException
    {
        if (parsed instanceof Long)
            return new Constants.Value(ByteBufferUtil.bytes((Long) parsed));

        try
        {
            return new Constants.Value(TimestampType.instance.fromString((String) parsed));
        }
        catch (ClassCastException exc)
        {
            throw new MarshalException(String.format(
                    "Expected a long or a datestring representation of a date value, but got a %s: %s",
                    parsed.getClass().getSimpleName(), parsed));
        }
    }

    @Override
    public String toJSONString(ByteBuffer buffer, ProtocolVersion protocolVersion)
    {
        return '"' + TimestampSerializer.getJsonDateFormatter().format(TimestampSerializer.instance.deserialize(buffer).toInstant()) + '"';
    }

    @Override
    public boolean isCompatibleWith(AbstractType<?> previous)
    {
        if (super.isCompatibleWith(previous))
            return true;

        if (previous instanceof TimestampType)

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