Styjun

I have camel rest endpoint with two params and when I send request it activates first route ("direct:amq"), where I get message from activeMq.

The headers here are okay, but this route activates another route ("direct:post)" and the headers there are missing.

I want to get the urlToPost Header from the first route in to the second.

 rest("/getFromActiveMq").produces("application/json")
 .get()
 .param()
 .name("urlToPost")
 .type(RestParamType.query)
 .dataType("String")
 .endParam()
 .param()
 .name("getactivemq")
 .type(RestParamType.query)
 .dataType("String")
 .endParam()
 .to("direct:amq");

from("direct:amq").streamCaching()
 .startupOrder(2)
 .log("My activemq is " + "$in.header.getactivemq")
 .log("My urlToPost is " + "$in.header.urlToPost")
 .setHeader("myHeader")
 .header("$in.header.urlToPost")
 .log("My urlToPost Changed header is " + "$header.myHeader")
 .process(exchange -> 
 String header = exchange.getIn().getHeader("urlToPost", String.class);
 System.out.println(header);
 exchange.getIn().setHeader("myShittyHeader", header);

 Map<String, Object> hdr = exchange.getIn()
 .getHeaders();
 for (Map.Entry<String, Object> entry : hdr.entrySet()) 
 System.out.println(entry.getKey() + "/" + entry.getValue());
 
 )
 .pollEnrich()
 .simple("activemq://$in.header.getactivemq")
 .onCompletion()
 .log("My body is : " + "$body")
 .to("direct:post");

from("direct:post").tracing()
 .process(exchange -> exchange.getIn()
 .setBody(exchange.getIn()
 .getBody()))
 .convertBodyTo(String.class)
 .process(exchange -> 
 Map<String, Object> hdr = exchange.getIn()
 .getHeaders();
 for (Map.Entry<String, Object> entry : hdr.entrySet()) 
 System.out.println(entry.getKey() + "/" + entry.getValue());
 
 )
 .log("My urlToPost BEFORE SETTING HEADERS is " + "$in.header.urlToPost")
 .setHeader("Content-Type", constant("application/json"))
 .setHeader("Accept", constant("application/json"))
 .setHeader(Exchange.HTTP_METHOD, constant("POST"))
 .log("My urlToPost AFTER SETTING HEADERS is " + "$in.header.urlToPost")
 // .log("My HTTP_URI is: " + "$in.header.urlToPost")
 // .to("http4://urlToPost")
 // .to("direct:nothing");
 .enrich()
 .simple("http4://urlToPost");

I found that after:

.pollEnrich()
.simple("activemq://$in.header.getactivemq")

Headers are gone

The pollEnrich merges your current Exchange with another message. That means it is in effect an Aggregator.

If you don't provide an aggregation strategy, Camel uses by default a simple body aggregation. This is the reason why you lose your headers.

You have to configure a pre-existing or implement your own aggregation strategy that respects the headers of one or both messages during aggregation.