RouterSpec channelMapping takes no MessageChannel.

[dschulten]

Affects Version(s): 5.1.3

Enhancement

AbstractRouterSpec.defaultOutputChannel takes both a channelName and a MessageChannel.
However, RouterSpec.channelMapping only takes a channelName, but not a MessageChannel.

When using the DSL, I try to avoid explicit channel names and prefer the IntegrationFlow.getInputChannel() method to look up the input channel for a flow.

Currently I must use "mySubflow.input" for the channelMapping but I can use defaultOutputChannel(mySubFlow().getInputChannel()) for the default.

[artembilan]

The current implementation fully honors a target AbstractMappingMessageRouter contract which is only based on the channel names:

void setChannelMapping(String key, String channelName);
...
void setChannelMappings(Map<String, String> channelMappings);

We can improve the RouterSpec to accept a MessageChannel as well, but you need to ensure that your channel is a NamedComponent over there. Since the target AbstractMappingMessageRouter expects from us only channel names.

As a workaround your can do something like this:

m -> m.channelMapping(true, ((NamedComponent) myFlow.getInputChannel()).getComponentName())

Feel free to raise a Pull Request with such an improvement.
We would need to check for NamedComponent in a new channelMapping() method before calling a delegate.