lets say for an example i have a code:

```
       from(servlet://abc?id={id}&name={name}).process(new Processor(){
     @Override
        public void process(Exchange arg0) throws Exception {
            id = arg0.getIn().getHeader("id", String.class);
            id_type = arg0.getIn().getHeader("name",String.class);

            System.out.println(id);
            System.out.println(name);
            String url = "//example.com/"+id+"?name="+name;
            System.out.println(url);

            /*Thread.sleep(10000);*/

        }.setHeader(Exchange.HTTP).to("http:"+url+"&bridgeEndpoint=true&throwExceptionOnFailure=false)"

```

I dont see my url there. its showing null value. how to solve this problem? I used to set this string in Exchange header but its giving me java.lang.IllegalArgumentException: