Logging in Chain

[ctapobep]

I have a chain configured, there are elements like filters, transformers and validators. I'd like to add logging between them, is it possible? Don't want to create a separate class for logging, would like to use standard logging-channel-adapter.

    <si:chain input-channel="input">
        <si:transformer ref="some transformer"/>
        <si:filter ref="validator" discard-channel="validation.failure"/>
        <si:splitter ref="another transformer">
            <jdbc:outbound-channel-adapter channel="jdbcinputchannel" data-source="dataSource">
                <jdbc:query>
                    query
                </jdbc:query>
            </jdbc:outbound-channel-adapter>
        </si:splitter>
    </si:chain>

[Gary Russell]

Well, the <chain/> is really intended as a black box.

<logging-channel-adapter/> won't work because that is a one-way element (no reply to send to the next component).

You'd have to do something like this...

public class Logger {
	
	private static Log logger = LogFactory.getLog(Logger.class);
			
	public Message<?> log(Message<?> message) {
		logger.info("CHAIN:" + message);
		return message;
	}

}

<beans:bean id="log" class="foo.Logger"/>

<si:chain input-channel="input">
        <service-activator ref="log" />
        <si:transformer ref="some transformer"/>
        <service-activator ref="log" /> 
        <si:filter ref="validator" discard-channel="validation.failure"/>
        <service-activator ref="log" />
        <si:splitter ref="another transformer">
            <jdbc:outbound-channel-adapter channel="jdbcinputchannel" data-source="dataSource">
                <jdbc:query>
                    query
                </jdbc:query>
            </jdbc:outbound-channel-adapter>
        </si:splitter>
        <service-activator ref="log" />
</si:chain>

Either that, or break up your chain and wire-tap explicit channels between the elements.

[ctapobep]

Eh.. I see, thanks for your answer!