How should I approach the following scenario? I’m starting to suspect that I'm
doing it wrong…
I'm using: Camel 2.11.0, Scala DSL, Scala 2.10.0, sbt 0.12.2, JDK 1.6.0_43, OSX
10.8.3
I have a route that takes a file, parses it and then sends JSON to a web
service. If the Camel processor that parses the file throws a parse exception,
the configured error handler moves the file to the dead letter endpoint. This
much works.
errorHandler(deadLetterChannel(failureEndpoint).disableRedelivery())
However, I *also* want to log an error with the parse exception that the parser
throws. How should I do this?
First, I’m confused by the documentation and examples I’ve found: they suggest
using a log or a file but not both. It isn’t weird to want to both move an
invalid input file to a dead letter 'failure' directory and to log the cause of
the failure. Should the error handler be doing both?
The following is as far as we got, adding our custom 'ErrorProcessor' so we
could customise the log output:
case class ErrorProcessor(implicit routeId: String) extends
CamelProcessor {
def process(exchange: Exchange): Unit = {
val formatString = "Error [%s] while processing [%s]"
val exception =
exchange.getProperty(Exchange.EXCEPTION_CAUGHT).asInstanceOf[Throwable]
val message = formatString.format(exception.getMessage,
exchange.getIn.getHeaders.get("CamelFileNameOnly").asInstanceOf[String])
Logger.error(message, exception)
}
}
…
val deadLetterErrorHandler =
deadLetterChannel(failureEndpoint).disableRedelivery()
deadLetterErrorHandler.setFailureProcessor(ErrorProcessor())
errorHandler(deadLetterErrorHandler)
This is okay, but I would prefer to encapsulate all of the above in a single
component that I can then give to errorHandler(…) for every route builder.
We tried to make a custom DeadLetterChannelBuilder, but it didn't work: we
tried overriding getFailureProcessor to return our customer error processor,
but its process method was never called.
What is the correct way to customise log output for DeadLetterChannelBuilder
whose endpoint is a directory that the message (file) will be moved to?
How much of this can I do using standard Camel components and the Scala DSL?
Peter
