UPDATED: Type resolution with deep generic hierarchies still fail in 2025.1.1 (regression from issue #1312)

Start by running the demo with ./mvnw spring-boot:run after checking the version changes in pom.xml, then follow the productBatchListConsumer bean and GenericBatchListConsumer signature described in the issue. Compare its batch payload with the working consumers; done means it deserializes to ProductCompleteDTO values instead of raw bytes while the existing single- and batch-mode consumers continue to work.

Description

This is a follow-up to issue #1312 ("Type resolution with deep generic hierarchies is incorrect"). After upgrading Spring Cloud BOM from 2025.0.0 to 2025.1.1 and Spring Boot to 4.0.3, type resolution issues persist in batch mode consumption.

The demo repository (ferblaca/demoStreamGenerics/tree/upgrade_to_2025_0_0) was re-tested to confirm the behavior.

Current Behavior

Single Mode - All Consumers Work ✅

• productConsumer (GenericConsumer<ProductCompleteDTO>)
• productConsumer2 (Consumer<ProductCompleteDTO>)
• productMessageConsumer (GenericMessageConsumer<ProductCompleteDTO>)
• productMessageConsumer2 (Consumer<Message<ProductCompleteDTO>>)

Batch Mode - Partial Failure ⚠️

• productBatchListConsumer (GenericBatchListConsumer<ProductCompleteDTO>): ❌ Fails — payload arrives as byte[........]
• productBatchListConsumer2 (Consumer<List<ProductCompleteDTO>>): ✅ Works
• productBatchListMessageConsumer (GenericBatchMessageListConsumer<ProductCompleteDTO>): ✅ Works
• productBatchListMessageConsumer2 (Consumer<Message<List<ProductCompleteDTO>>>): ✅ Works

Root Cause

Only the productBatchListConsumer bean with the following signature fails to deserialize correctly:

@Bean
public GenericBatchListConsumer<ProductCompleteDTO> productBatchListConsumer() {
    return new GenericBatchListConsumer<>("productBatchListConsumer");
}

Where GenericBatchListConsumer is defined as:

public class GenericBatchListConsumer<T> implements Consumer<List<T>> {
    // ...
}

Instead of deserializing to the expected type, the message payload arrives as raw bytes:

Received Batch List productBatchListConsumer Consumer: [123, 34, 105, 100, 34, 58, 49, ...]

Steps to Reproduce

1. Clone the demo repository
2. Update pom.xml with:
   • Spring Cloud BOM: 2025.1.1
   • Spring Boot: 4.0.3
3. Run ./mvnw spring-boot:run (Kafka starts automatically via Docker Compose)
4. Send the same test messages from the original issue
5. Check the logs for the byte array payload symptom

Environment