Path variables in Apache Camel rest route - rest

Question

I would like to use path variables in my REST route URL in the following way:
rest().post("/companies/{companyId}/branches/branchId={branchId}");
The companyId can be properly retrieved as header, however, "branchId={branchId}" is treated as literal string. Therefore request to:
/companies/100/branches/branchId=200 - will return 404 not found.
but
/companies/100/branches/branchId={branchId} - will enter the route.
I would like to use branchId as header, in the same way as companyId, without having to change the structure of the URL.

Answer 1

Every path or query parameter can be received through the headers in Apache Camel. You can retrieve the headers with using the simple expression;
${header.your-header}
So you can retrieve the parameters as below;
parameter
simple expression
companyId
${header.companyId}
branchId
${header.branchId}
Here is a working Route example that I've made for you;
package com.bzdgn.camelso.route;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.model.rest.RestBindingMode;
public class RestEndpointRoute extends RouteBuilder {
#Override
public void configure() throws Exception {
rest()
.post("/companies/{companyId}/branches/{branchId}")
.consumes("text/plain")
.produces("text/plain")
.to("direct:handle-post");
from("direct:handle-post")
.id("post-route")
.log("Received Body: ${body}")
.log("Company Id: ${header.companyId}")
.log("Branch Id: ${header.branchId}")
.setBody(simple("CompanyId = ${header.companyId} \nBranchId = ${header.branchId}"))
.convertBodyTo(String.class);
restConfiguration()
.component("netty-http")
.host("localhost")
.port("8080")
.bindingMode(RestBindingMode.auto);
}
}
The logs will be as below if you send a HTTP Post Request to the designated URL;
2021-05-28 21:13:30 INFO HttpServerBootstrapFactory:53 - BootstrapFactory on port 8080 is using bootstrap configuration: [NettyServerBootstrapConfiguration{protocol='http', host='localhost', port=8080, broadcast=false, sendBufferSize=65536, receiveBufferSize=65536, receiveBufferSizePredictor=0, workerCount=0, bossCount=1, keepAlive=true, tcpNoDelay=true, reuseAddress=true, connectTimeout=10000, backlog=0, serverInitializerFactory=org.apache.camel.component.netty.http.HttpServerInitializerFactory#ae3540e, nettyServerBootstrapFactory=null, options=null, ssl=false, sslHandler=null, sslContextParameters='null', needClientAuth=false, enabledProtocols='TLSv1,TLSv1.1,TLSv1.2, keyStoreFile=null, trustStoreFile=null, keyStoreResource='null', trustStoreResource='null', keyStoreFormat='JKS', securityProvider='SunX509', passphrase='null', bossGroup=null, workerGroup=null, networkInterface='null', reconnect='true', reconnectInterval='10000'}]
2021-05-28 21:13:30 INFO NettyComponent:164 - Creating shared NettyConsumerExecutorGroup with 17 threads
2021-05-28 21:13:31 INFO SingleTCPNettyServerBootstrapFactory:182 - ServerBootstrap binding to localhost:8080
2021-05-28 21:13:33 INFO NettyConsumer:77 - Netty consumer bound to: localhost:8080
2021-05-28 21:13:33 INFO AbstractCamelContext:2983 - Routes startup summary (total:2 started:2)
2021-05-28 21:13:33 INFO AbstractCamelContext:2988 - Started post-route (direct://handle-post)
2021-05-28 21:13:33 INFO AbstractCamelContext:2988 - Started route1 (rest://post:/companies/%7BcompanyId%7D/branches/%7BbranchId%7D)
2021-05-28 21:13:33 INFO AbstractCamelContext:3000 - Apache Camel 3.10.0 (camel-1) started in 3s337ms (build:93ms init:274ms start:2s970ms)
2021-05-28 21:13:35 INFO post-route:166 - Received Body: Example text body here
2021-05-28 21:13:35 INFO post-route:166 - Company Id: my-custom-company
2021-05-28 21:13:35 INFO post-route:166 - Branch Id: my-custom-branch-id
And you can test it via postman like this. The request, and the headers listed in the below images, and do not forget to add "Content Type: text/plain", because that's defined in the route that it will consume and produce "text/plain".