How to set Cache-Control headers in Apache Camel - apache-camel

Question

I am using Apache camel 2.15.1 version. In this I am using servlet component for rest dsl. My simple route looks like below
from(rest:get:CustomerDetails.json)
.to("http://localhost:8080/customer/getCustomerDetails?bridgeEndpoint=true");
I have a requirement to set Cache-Control and Pragma headers for response.
from(rest:get:CustomerDetails.json)
.to("http://localhost:8080/customer/getCustomerDetails?bridgeEndpoint=true")
.setHeader("Cache-Control",constant("private, max-age=0,no-store"));
But camel ignores this. I read few others blog which suggests to use a custom HeaderFilterStrategy. I tried with this as well. It didn't help.
https://access.redhat.com/documentation/en-US/Red_Hat_JBoss_Fuse/6.0/html/Web_Services_and_Routing_with_Camel_CXF/files/Proxying-Headers.html
https://issues.apache.org/jira/browse/CAMEL-6085
Any help to fix this issue is highly appreciated.

Answer 1

You can get it to work with custom HeaderFilterStrategy. The trick is to configure it in restConfiguration().endpointProperties(..) like this:
public void configure() {
JndiRegistry registry = getContext().getRegistry(JndiRegistry.class);
registry.bind("filter", new HeaderFilter());
restConfiguration()
.host("localhost")
.endpointProperty("headerFilterStrategy","#filter")
.setPort("10000");
from("rest:get:hello")
.to("http://localhost:20000?bridgeEndpoint=true")
.setHeader("Cache-Control",constant("private, max-age=0,no-store"));
from("netty-http:http://localhost:20000")
.setBody(constant("ok"));
}
where #filter is just dummy implementation like this (you can create a filter that suits better your needs)
public class HeaderFilter implements HeaderFilterStrategy {
#Override
public boolean applyFilterToCamelHeaders(String arg0, Object arg1, Exchange arg2) {
// TODO Auto-generated method stub
return false;
}
#Override
public boolean applyFilterToExternalHeaders(String arg0, Object arg1, Exchange arg2) {
// TODO Auto-generated method stub
return false;
}
}
Now if if run my routes without .endpointProperty("headerFilterStrategy","#filter") line I get output like this
$ curl -D - http://localhost:10000/hello
HTTP/1.1 200 OK
Accept: */*
breadcrumbId: ID-myhost-40508-1441899753215-0-1
User-Agent: curl/7.35.0
Content-Length: 2
Connection: keep-alive
ok
and with .endpointProperty("headerFilterStrategy","#filter") line output like this
$ curl -D - http://localhost:10000/hello
HTTP/1.1 200 OK
Accept: */*
breadcrumbId: ID-myhost-56308-1441899833287-0-1
Cache-Control: private, max-age=0,no-store
CamelHttpMethod: GET
CamelHttpResponseCode: 200
CamelHttpUri: /hello
CamelHttpUrl: http://localhost:10000/hello
CamelNettyChannelHandlerContext: org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext#1fac34b
CamelNettyLocalAddress: /127.0.0.1:10000
CamelNettyMessageEvent: [id: 0x93dfe147, /127.0.0.1:35302 => /127.0.0.1:10000] RECEIVED: DefaultHttpRequest(chunked: false) GET /hello HTTP/1.1 User-Agent: curl/7.35.0 Host: localhost:10000 Accept: */*
CamelNettyRemoteAddress: /127.0.0.1:35302
User-Agent: curl/7.35.0
Content-Length: 2
Connection: keep-alive
ok