while \'playing around\' with Camel using Spring DSL, I came across the following problem. Suppose the expected message flow looks like this:
I leave you some examples:
someValue
${properties:userName} //from config
${in.body}
//item[1]/orderNumber/text()
Getter
${exchangeProperty[orderNumber]}
${in.headers.token}
Documentation
Check the simple expression language: http://camel.apache.org/simple.html
Sometimes looking at the test cases of Camel can be helpful as well, in particular for Spring DSL: