[CAMEL-11749] NoTypeConversionAvailableException in wiretap

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 2.19.2
• Component/s: camel-core
• Estimated Complexity: Unknown
• Assignee: Claus Ibsen
• Reporter: Keegan Witt
• Created: 05/Sep/17 18:47
• Updated: 06/Sep/17 14:56
• Resolved: 06/Sep/17 06:43

Description

1. Clone https://github.com/apache/camel/tree/master/examples/camel-example-spring-boot
2. Add CamelLogger.java with contents below to src/main/java/org/apache/camel/examples

CamelLogger.java

package org.apache.camel.examples;
import org.apache.camel.Exchange;
import org.apache.camel.Processor;
import org.springframework.stereotype.Component;

@Component
public class CamelLogger implements Processor {
    @Override
    public void process(Exchange exchange) {
        System.err.println(exchange.getIn().getBody());
    }
}

Changing SampleCamelRouter to

@Component
public class SampleCamelRouter extends RouteBuilder {
    @Override
    public void configure() throws Exception {
        from("timer:hello?period={{timer.period}}")
                .transform(method("myBean", "saySomething"))
                .wireTap("bean:camelLogger")
                .to("stream:out");
    }
}

Fails with stacktrace

Stacktrace
---------------------------------------------------------------------------------------------------------------------------------------

org.apache.camel.NoTypeConversionAvailableException: No type converter available to convert from type: null to the required type: java.lang.String with value null
	at org.apache.camel.impl.converter.BaseTypeConverterRegistry.mandatoryConvertTo(BaseTypeConverterRegistry.java:206) ~[camel-core-2.20.0-20170905.112154-218.jar:2.20.0-SNAPSHOT]
	at org.apache.camel.processor.SendDynamicProcessor.resolveEndpoint(SendDynamicProcessor.java:144) ~[camel-core-2.20.0-20170905.112154-218.jar:2.20.0-SNAPSHOT]
	at org.apache.camel.processor.SendDynamicProcessor.process(SendDynamicProcessor.java:104) ~[camel-core-2.20.0-20170905.112154-218.jar:2.20.0-SNAPSHOT]
	at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:548) ~[camel-core-2.20.0-20170905.112154-218.jar:2.20.0-SNAPSHOT]
	at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:201) [camel-core-2.20.0-20170905.112154-218.jar:2.20.0-SNAPSHOT]
	at org.apache.camel.processor.DelegateAsyncProcessor.process(DelegateAsyncProcessor.java:97) [camel-core-2.20.0-20170905.112154-218.jar:2.20.0-SNAPSHOT]
	at org.apache.camel.processor.WireTapProcessor$1.call(WireTapProcessor.java:158) [camel-core-2.20.0-20170905.112154-218.jar:2.20.0-SNAPSHOT]
	at org.apache.camel.processor.WireTapProcessor$1.call(WireTapProcessor.java:153) [camel-core-2.20.0-20170905.112154-218.jar:2.20.0-SNAPSHOT]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_144]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_144]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_144]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_144]

With Camel 2.15.5 or with SampleCamelRouter of content below, exception doesn't occur.

@Component
public class SampleCamelRouter extends RouteBuilder {
    @Resource CamelLogger camelLogger;

    @Override
    public void configure() throws Exception {
        from("timer:hello?period={{timer.period}}")
                .transform(method("myBean", "saySomething"))
                .wireTap("direct:logging")
                .to("stream:out");
        from("direct:logging").process(camelLogger);
    }
}

I didn't see anything in release notes in 2.16, 2.17, 2.18, or 2.19 that would indicate there's a change in behavior from 2.15 in this regard. Either this is a bug that should be fixed, or the change in behavior should be documented.

Issue Links

• is a clone of: CAMEL-11683 Allow bean references in to() URI
• relates to: CAMEL-11755 toD should ignore when dynamic uri is empty