Hello

In the StreamBridge class, the method getStreamBridgeFunction uses the method hashProducerProperties to get the key in the cache.

Here's my configuration :

one topic with 2 partitions one with partition-key-expression and one without partition-key-expression

spring:
  cloud:
    stream:
      bindings:
        binding1:
          producer:
            partitionCount: 2
          content-type: application/json
          destination: topic1
        binding2:
          producer:
            partition-key-expression: headers['partitionKey']
            partitionCount: 8
          content-type: application/json
          destination: topic2

Because the difference of hash of Boolean.hashcode(boolean value) is 6.

public static int hashCode(boolean value) {
    return value ? 1231 : 1237;
}

The hash for binding1 will be
outputContentType.hashCode() --> X

• Boolean.hashCode(producerProperties.isUseNativeEncoding()) --> Y
• Boolean.hashCode(producerProperties.isPartitioned()) --> 1237
• producerProperties.getPartitionCount(); --> 2

The hash for binding 2 will be
outputContentType.hashCode() --> X

• Boolean.hashCode(producerProperties.isUseNativeEncoding()) --> Y
• Boolean.hashCode(producerProperties.isPartitioned()) --> 1231
• producerProperties.getPartitionCount(); --> 8

So hash for binding1 = hash for binding2 = X + Y + 1239

The cache will return the same function, I have an error on binding1 because I don't provide the header "partition-key" if the first one used (and put in cache) is binding2

Thanks