The @javax.ws.rs.HEAD annotation designates a method to respond to the HTTP HEAD requests. The HEAD method is the same as the GET request, but it only transfers the status line along with the header section (without the response body) to the client. This method is useful for retrieving the metadata present in the response headers, without having to retrieve the message body from the server. You can use this method to check whether a URI pointing to a resource is active or to check the content size by using the Content-Length response header field.

The JAX-RS runtime will offer the default implementations for the HEAD method type if the REST resource is missing explicit implementation. The default implementation provided by the runtime for the HEAD method will call the method designated for the GET request type, ignoring the response entity returned by the method.