laymain opened a new issue, #3515:
URL: https://github.com/apache/parquet-java/issues/3515

   ## Summary
   
   Avro 1.12.1 introduces a breaking change that affects `parquet-avro` users. 
Multiple logical types are now deserialized to their proper Java types instead 
of their underlying primitive types when using `ReflectData`, causing 
`ClassCastException` in existing code.
   
   ## Background
   
   - **Upstream issue:** https://issues.apache.org/jira/browse/AVRO-3989
   - **Pull request:** https://github.com/apache/avro/pull/3354
   - **Avro version affected:** 1.12.1 (released as a patch version)
   
   ## Problem
   
   The fix in AVRO-3989 changed the deserialization behavior for ALL logical 
types. When using parquet-avro's `ReflectData` class, these fields now return 
their logical Java type objects instead of their underlying primitive types 
from `GenericRecord`.
   
   ### Affected logical types and conversions:
   
   | Logical Type | Old Type (≤1.12.0) | New Type (1.12.1) |
   |--------------|-------------------|-------------------|
   | `timestamp-millis` | `Long` | `Instant` |
   | `timestamp-micros` | `Long` | `Instant` |
   | `date` | `Integer` | `LocalDate` |
   | `time-millis` | `Integer` | `LocalTime` |
   | `time-micros` | `Long` | `LocalTime` |
   | `local-timestamp-millis` | `Long` | `LocalDateTime` |
   | `local-timestamp-micros` | `Long` | `LocalDateTime` |
   | `uuid` | `String` | `UUID` |
   | `decimal` | `ByteBuffer` | `BigDecimal` |
   
   This breaks existing code that expects primitive values:
   
   ```java
   // This used to work in Avro 1.12.0
   Long timestamp = (Long) genericRecord.get("timestamp_field");
   Integer date = (Integer) genericRecord.get("date_field");
   String uuid = (String) genericRecord.get("uuid_field");
   
   // In Avro 1.12.1, all of these throw ClassCastException
   // because values are now Instant, LocalDate, UUID, etc.
   ```
   
   ## Impact
   
   - **Widespread breakage:** Affects anyone using parquet-avro with ANY 
logical types
   - Code that has worked for years suddenly breaks after a patch version update
   - The breaking nature wasn't clearly documented in Avro's changelog
   - This is a significant behavior change that affects the entire logical type 
system
   
   ## Heads up for future avro updates
   
   I apologize if this isn't the right place to report this, please feel free 
to redirect me if there's a better venue for this discussion. My main goal is 
to ensure that when parquet-java does consider updating Avro, the team and 
users are aware of this significant behavioral change.
   
   ## For Current Users
   
   If you're using parquet-avro and explicitly upgrading Avro to 1.12.1+ in 
your project, be aware of this breaking change. You'll need to update code that 
reads logical type fields from `GenericRecord`.


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