apache/iceberg · error · IllegalArgumentException

Unexpected object type for TIMESTAMP logical type. Received:

Error message

Unexpected object type for TIMESTAMP logical type. Received: 

What it means

convertToTimestamp throws IllegalArgumentException when the Avro reader produces an object for a TIMESTAMP logical type that is neither java.time.LocalDateTime nor a Joda-time convertible object (and no Joda converter is available).

Source

Thrown at flink/v2.3/flink/src/main/java/org/apache/iceberg/flink/formats/avro/AvroToRowDataConverters.java:251

        return TimestampData.fromEpochMillis(timeLong);
      } else if (precision <= 6) {
        return TimestampData.fromEpochMillis(
            Math.floorDiv(timeLong, 1000L), (int) Math.floorMod(timeLong, 1000L) * 1000);
      } else {
        // Iceberg: Added support for nanoseconds precision (FLINK-39251)
        return TimestampData.fromEpochMillis(
            Math.floorDiv(timeLong, 1_000_000L), (int) Math.floorMod(timeLong, 1_000_000L));
      }
    } else if (object instanceof Instant) {
      return TimestampData.fromInstant((Instant) object);
    } else if (object instanceof LocalDateTime) {
      return TimestampData.fromLocalDateTime((LocalDateTime) object);
    } else {
      JodaConverter jodaConverter = JodaConverter.getConverter();
      if (jodaConverter != null) {
        return TimestampData.fromEpochMillis(jodaConverter.convertTimestamp(object));
      } else {
        throw new IllegalArgumentException(
            "Unexpected object type for TIMESTAMP logical type. Received: " + object);
      }
    }
  }

  private static int convertToDate(Object object) {
    if (object instanceof Integer) {
      return (Integer) object;
    } else if (object instanceof LocalDate) {
      return (int) ((LocalDate) object).toEpochDay();
    } else {
      JodaConverter jodaConverter = JodaConverter.getConverter();
      if (jodaConverter != null) {
        return (int) jodaConverter.convertDate(object);
      } else {
        throw new IllegalArgumentException(
            "Unexpected object type for DATE logical type. Received: " + object);
      }

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Ensure the Avro reader returns java.time.LocalDateTime for timestamp fields (use a matching Avro datum reader version)
2. Add org.joda:joda-time to the classpath if reading data produced by old Avro writers
3. Normalize upstream Avro writing to the ISO/LocalDateTime encoding this converter expects

Example fix

// before
Object object = record.get("ts"); // java.util.Date — throws
// after
LocalDateTime object = ((Instant) record.get("ts")).atZone(ZoneOffset.UTC).toLocalDateTime();

if (!(object instanceof LocalDateTime) && !isJodaDateTime(object)) { throw new IllegalArgumentException("Expected LocalDateTime for TIMESTAMP field, got " + object.getClass()); }

boolean isTimestampDatum(Object o) { return o instanceof LocalDateTime || o instanceof org.joda.time.LocalDateTime; }

try { return convertToTimestamp(object); } catch (IllegalArgumentException e) { throw new IllegalStateException("Avro writer produced unexpected timestamp encoding: " + e.getMessage(), e); }

When it happens

Trigger: Avro datum is e.g. a java.util.Date, Long, or Instant while the converter expects LocalDateTime or a Joda class; Joda-Time not on classpath so legacy objects cannot be converted.

Common situations: Mixed Avro writer versions: newer writers emit java.time types, older writers emit Joda or millis-Long; missing joda-time dependency in the Flink job.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• Unexpected object type for TIMESTAMP logical type. Received:
• Unexpected object type for TIMESTAMP logical type. Received:
• Unexpected object type for TIMESTAMP logical type. Received:
• Unexpected object type for DATE logical type. Received:
• Unexpected object type for TIME logical type. Received:

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/48d8904a3b4ba2c5. Report an issue: GitHub.