如何使用Apache Camel仅加载单个文件？

Question

Apache Camel has a very nice support for various protocols like FTP and "file" and I would like to use it just to just load a single file and maybe convert it a bit.

I understood how to do this using a RouteBuilder and CamelContext.start() like in the examples but I don't want a background daemon in an endless loop nor do I need complex routing.

How can I do something like:

String body = new DefaultCamelContext().justRunOnce(
   from("ftp://ftp.example.com/data/foo.txt")
     .validate(body().regex("My Data.*"))
     .getBody());

I did read some answers on how to stop a Route using "controlbus?action=stop" or "timer?repeat=1" or similar but those still start Camel as a new thread and then use some hack to stop it. I'm not looking for a complicated solution that somehow manages it but rather would like to know if Camel is capable to be used in a lean 10-liner, like in my example above.

Answer 1

You can use the pollEnricht feature, see http://camel.apache.org/content-enricher.html :

Example, you can also use a ftp endpoint instead of a file endpoint:

<route>
 <from uri="direct:start"/>
  <pollEnrich>
   <constant>file:inbox?fileName=data.txt</constant>
  </pollEnrich>
<to uri="direct:result"/>