Summary

4.9.x versions of the Java driver would handle this scenario gracefully:

A class with a property like:

public Map<String, MyGenericType<Animal>> decorators;

where Animal is an abstract class with a discriminator.

Such a field in a class now produces:

CodecConfigurationException with the message: "[x] contains generic types that have not been specialised. Top level classes with generic types are not supported by the PojoCodec."

Please provide the version of the driver. If applicable, please provide the MongoDB server version and topology (standalone, replica set, or sharded cluster).

Version 4.11.x of the Java driver produces the error.  Version 4.9.x of the driver works fine.

This is also affecting a widely used Java library, Quarkus: https://github.com/quarkusio/quarkus/issues/36397