WireTap configuration in Spring Integration Java DSL

Question

I've added WireTap configuration to my Spring Integration Java DSL.

I reviewed discussion What is the equivalent of logging-channel-adapter in java DSL and now my main Java Config file looks like

@Configuration
@Import(LoggerConfiguration.class)
@EnableIntegration
public class ProcessorConfiguration {

    @Autowired
    private WireTap wireTap;

    @Bean
    public QueueChannel inputChannel() {
        return MessageChannels.queue(500)
            .interceptor(wireTap)
            .get();
    }

    @Bean
    public PublishSubscribeChannel outputChannel() {
        return MessageChannels.publishSubscribe()
            .interceptor(wireTap)
            .get();
    }
    ...
}

And LoggerConfiguration is

@Configuration
public class LoggerConfiguration {

    public static final LoggingHandler.Level INFO = LoggingHandler.Level.INFO;

    @Bean
    public WireTap wireTap() {
        return new WireTap(loggerChannel());
    }

    @Bean
    public IntegrationFlow loggerChain() {
        return IntegrationFlows.from(loggerChannel())
               .handle(loggerHandler())
               .get();
    }

    @Bean
    public MessageChannel loggerChannel() {
        return MessageChannels.direct().get();
    }

    public MessageHandler loggerHandler() {
        LoggingHandler loggingHandler = new LoggingHandler(INFO.name());
        ...  
        return loggingHandler;
   }
}

All of thes tones(!) of code ONLY to reach what I had in XML configuration in these simple lines

<int:channel id="inputChannel">
    <int:queue capacity="500"/>
    <int:interceptors>
        <int:wire-tap channel="logger"/>
    </int:interceptors>
</int:channel>

<int:publish-subscribe-channel id="outputChannel">
    <int:interceptors>
        <int:wire-tap channel="logger"/>
    </int:interceptors>
</int:publish-subscribe-channel>

<int:logging-channel-adapter id="logger" log-full-message="true" level="INFO"/>

How can I configure wireTaps in Java DSL less verbose and simple?

Artem Bilan Artem Bilan · Accepted Answer · 2016-02-27T02:54:45

Since you really don't have there a flow you can just end up with the:

@ServiceActivator(inputChannel = "loggerChannel") 
public MessageHandler loggerHandler() {
     LoggingHandler loggingHandler = new LoggingHandler(INFO.name());
     ...  
     return loggingHandler;
}

No reason to declare a "verbose" IntegrationFlow if there is only the simple handle logic.

The Java DSL really can be combined with the raw Java & Annotation configuration and even the XML configs can live there as well.

WireTap may not be declared as a @Bean:

@Bean
public PublishSubscribeChannel outputChannel() {
    return MessageChannels.publishSubscribe()
        .interceptor(new WireTap(loggerChannel()))
        .get();
}

The XML definition declares bean for the <int:wire-tap> via a Parser logic.

With Java configuration we don't have so much choice, unless @Bean for the target class if we would like to have it as a bean.

From other side the Java DSL has .wireTap() EIP-method. So, you don't need to declare all those beans. E.g. from our test-cases:

@Bean
public IntegrationFlow wireTapFlow5() {
    return f -> f
            .wireTap(sf -> sf
                    .<String, String>transform(String::toUpperCase)
                    .channel(c -> c.queue("wireTapSubflowResult")))
            .channel("nullChannel");
}

As you see we don't have any extra @Bean there and even we don't need the extra channel for the WireTap.

Let me know how more simple would you like to see it!

WireTap configuration in Spring Integration Java DSL

1 Answers