How to get access to HTTP header information in Spring MVC REST controller?

When you annotate a parameter with @RequestHeader, the parameter retrieves the header information. So you can just do something like this:

@RequestHeader("Accept")

to get the Accept header.

So from the documentation:

@RequestMapping("/displayHeaderInfo.do")
public void displayHeaderInfo(@RequestHeader("Accept-Encoding") String encoding,
                              @RequestHeader("Keep-Alive") long keepAlive)  {

}

The Accept-Encoding and Keep-Alive header values are provided in the encoding and keepAlive parameters respectively.

And no worries. We are all noobs with something.

You can use the @RequestHeader annotation with HttpHeaders method parameter to gain access to all request headers:

@RequestMapping(value = "/restURL")
public String serveRest(@RequestBody String body, @RequestHeader HttpHeaders headers) {
    // Use headers to get the information about all the request headers
    long contentLength = headers.getContentLength();
    // ...
    StreamSource source = new StreamSource(new StringReader(body));
    YourObject obj = (YourObject) jaxb2Mashaller.unmarshal(source);
    // ...
}