Spring-Integration: Changing DirectChannel to ExecutorChannel results to ClassCastException

Question

I want to use a executor-channel instead of an direct-channel, but I face an issue I don`t understand.

Working Config:

<int:channel id="newByteArrayChannel" datatype="java.lang.Byte[]" />

<int:service-activator 
    id="myEncryptionServiceActivator"
    ref="encryptionServiceConnector" 
    method="encrypt"
    input-channel="newByteArrayChannel"
    output-channel="encryptedByteArrayChannel" 
    requires-reply="true"
    send-timeout="1000" 
/>

Changed to (Not Working):

<int:channel id="newByteArrayChannel" datatype="java.lang.Byte[]">
    <int:dispatcher task-executor="myExecutor" />
</int:channel>
<task:executor id="myExecutor" pool-size="4" queue-capacity="10" keep-alive="10000"/>

<int:service-activator 
    id="myEncryptionServiceActivator"
    ref="myServiceConnector" 
    method="encrypt"
    input-channel="newByteArrayChannel"
    output-channel="encryptedByteArrayChannel" 
    requires-reply="true"
    send-timeout="1000" 
/>

Error:

Exception in thread "main" org.springframework.messaging.MessageDeliveryException: Channel 'newByteArrayChannel' expected one of the following datataypes [class [Ljava.lang.Byte;], but received [class [B]

Thanks in advance :-)

Answer 1

It's a bug - I opened a JIRA Issue.

As a work-around, you could bridge a direct channel to the executor channel, or change newByteArrayChannel to a publish subscribe channel - (with only one subscriber, or course).

<int:publish-subscribe-channel id="newByteArrayChannel" 
      datatype="java.lang.Byte[]" task-executor="myExecutor" />

Or you can explicitly inject a DefaultDatatypeChannelMessageConverter bean into the channel.