title: "Template is null or has zero length" with jersey declarative hyperlinking
body: <p>I'm trying to integrate the declarative hyperlinking by following examples I found here and there. I came across some using <code>... value = "/systemusers/{id}" ...</code> and some using <code>... resource = SystemUser .class ...</code>. In my code, if I use the first solution I have the link correctly injected in my JSon response, while with the latter I get an <code>"Template is null or has zero length"</code> error. What is the problem and which template is the error referring to?
  Here is my code snippet:</p>
  
  <pre><code>@XmlRootElement
  public class SystemUser extends Account
  {
    private String                        addrRow1;
    private String                        addrRow2;
    private String                        addrRow3;
    private String                        postCode;
    private String                        city;
    private String                        country;
    private String                        responsiblePerson;           // npid der resp. person
    private String                        responsibleAgroup;
    private String                        project;
    private String                        personRole;                  // for ex. selfreg_host, technical, nethz_guest, ...
  
    @InjectLink( value = "/users/{npid}", style = Style.ABSOLUTE, bindings = @Binding( name = "npid", value = "${instance.npid}" ), rel = "self" )
    @XmlJavaTypeAdapter( XmlAdapter.class )
    @XmlElement( name = "link" )
    Link                                  self;
  ...
  </code></pre>
  
  <p>As said, if I specify the <code>value</code> parameter I get</p>
  
  <pre><code>"link": {
          "uri": "/IAMWS/services/users/10",
          "params": {
              "rel": "self"
          },
          "type": null,
          "rel": "self",
          "title": null,
          "rels": [
              "self"
          ],
          "uriBuilder": {
              "absolute": false
          }
      }
  </code></pre>
  
  <p>while if I specify the <code>resource</code> parameter i get:</p>
  
  <pre><code>javax.servlet.ServletException: java.lang.IllegalArgumentException: Template is null or has zero length
      org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:487)
      org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:425)
      org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:383)
      org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:336)
      org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:223)
      org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
  ...
  </code></pre>
  
  <p>What am I missing?</p>