[SOLVED] How to escape regex in Java methods call in simple language in Apache's Camel Spring DSL (XML) route?

How to escape regex in Java methods call in simple language in Apache's Camel Spring DSL (XML) route?

I have a setHeader tag in my route:

<setHeader headerName="timestampPart3"><simple>${header.timestampPart2.split("\\.")[0]}</simple></setHeader>
<log message="After: ${body} ${headers}"/>

I expect, it will split the String inside the timestampPart2 header and take the first element.

In fact, it just ignores the splitting:

timestampPart2=114128.0, timestampPart3=114128.0

So how I should implement regex escaping in Spring DSL? If for some reason it is impossible, how to work that around?

Solution

To set an Exchange message header you would need to use the name field and not the headerName field:

<setHeader name="timestampPart3">
    <simple>some-simple-expression</simple>
</setHeader>

Additionally you need to provide a raw regex expression for string #split method that will get sanitized (if needed) under the hood automatically by the OGNL - Camel parsing layer for you:

<setHeader name="timestampPart3">
    <simple>${header.timestampPart2.split("\.")[0]}</simple>
</setHeader>

Note the single back-slack character escaping the . special character. In short, you should provide a regular expression without escaping control sequences as you would do when inputing the same regular expression through a compile String literal in Java (it is raw XML (input stream) after all)