title: Why is Jackson serializing numeric fields to Strings?
body: <p>I have the following Jersey resource, Jersey has been configured to use Jackson for automatic JSON-POJO conversion:</p>
  
  <pre><code>@Path("/test")
  public class TestResource {
      @POST
      @Consumes({ MediaType.APPLICATION_JSON })
      @Produces({ MediaType.APPLICATION_JSON })
      public TestResponse testGet(final TestRequest req) {
          final TestResponse response = new TestResponse();
          response.x = req.x + 1;
          return response;
      }
  
      @XmlRootElement
      public static class TestRequest {
          public int x;
      }
  
      @XmlRootElement
      public static class TestResponse {
          public int x;
      }
  }
  </code></pre>
  
  <p>I call this with:</p>
  
  <pre><code>{"x":5}
  </code></pre>
  
  <p>And get the response:</p>
  
  <pre><code>{"x":"6"}
  </code></pre>
  
  <p>But why is the value here a string, when the x field in TestResponse is an int?</p>