Apache Camel: Accessing CamelLoopIndex - apache-camel

Question

I have the following route DSL:
from("file:" + autoLoadBaseDir + "?move=.classified")
.loop(fileTypes.length)
.choice()
.when(header("CamelFileName").contains(fileTypes[Integer.valueOf("${CamelLoopIndex}")]))
.to("file:" + classesBaseDir + "/" + fileTypes[Integer.valueOf("${CamelLoopIndex}")]);
As shown, I wish to access the CamelLoopIndex and use it as an index in an array. The expression is not evaluated, hence the route is not created. What am I doing wrong? Thanks in advance.
Documentation on this is pretty scanty, and I've not been successful getting a solution after hours of searching.
UPDATE: I've posted the same question to the Camel Users Mailing List.

Answer 1

You should use ${property.CamelLoopIndex}

Answer 2

you can use a processor or directly access the property
${exchangeProperty.CamelLoopIndex}
...
.loop(4)
.log("${exchangeProperty.CamelLoopIndex}")
.process(exchange -> {
Integer index = (Integer) exchange.getProperty(Exchange.LOOP_INDEX);
})
.end()
...
https://camel.apache.org/components/latest/eips/loop-eip.html
https://camel.apache.org/manual/latest/processor.html
Hope this helps

Answer 3

I'm late to the party but maybe somebody will get help from this answer. In the example given above this works for me for accessing the loop index in the Java DSL.
property(Exchange.LOOP_INDEX)
So for the example in the first post from okello above I guess this will work
Integer.valueOf(property(Exchange.LOOP_INDEX).toString())

Answer 4

Having experimented around with a number of options, the following works for me:
from("file:" + autoLoadBaseDir + "?preMove=inprogress&move=.classified")
.routeId("Test-Route")
.loop(fileTypes.length)
.processRef("keFileTypeNameService")
.choice()
.when(header("CamelFileName").contains(header("MyFileType")))
.to("file:" + classesBaseDir + "/?autoCreate=true&fileName=${header[MyFileType]}/${header[CamelFileName]}");
The keFileTypeNameService retrieves the CamelLoopIndex property from the exchange. It then uses this to get the file type at that index. It then just simply set this file type name in the header. The keFileTypeNameService bean is shown below:
#Service( value = "keFileTypeNameService" )
public class FileTypeNameService implements Processor {
private #Value("${ke.file.types}") String[] fileTypes;
public void process(Exchange exchange) throws Exception {
Integer count = exchange.getProperty("CamelLoopIndex", Integer.class);
String fileType = fileTypes[count];
exchange.getIn().setHeader("MyFileType", fileType);
}
}
I hope this assists someone else.