title: Code 400, Unrecognized field "customer" not marked as ignorable
body: <p>My problem:</p>
  
  <p>I`ve built a rest client within my iphone-application with restkit 0.20. 
  My RESTService was built with jax-rs including jackson.</p>
  
  <p>There is one class named "Customer", where I hold my customer data.</p>
  
  <pre><code>@XmlRootElement                                
  public class Customer extends BaseEntity {
  
  private int customer_id;
  private String appell;
  private String firstname;
  private String lastname;
  private Date birthday;
  private String street;
  private String streetnr;
  private String zipcode;
  private String place;
  
  public int getCustomer_id() {
      return customer_id;
  }
  
  public void setCustomer_id(int customer_id) {
      this.customer_id = customer_id;
  }
  
  public String getAppell() {
      return appell;
  }
  
  public void setAppell(String appell) {
      this.appell = appell;
  }
  
  public String getFirstname() {
      return firstname;
  }
  
  public void setFirstname(String firstname) {
      this.firstname = firstname;
  }
  
  public String getLastname() {
      return lastname;
  }
  
  public void setLastname(String lastname) {
      this.lastname = lastname;
  }
  
  public Date getBirthday() {
      return birthday;
  }
  
  public void setBirthday(Date birthday) {
      this.birthday = birthday;
  }
  
  public String getStreet() {
      return street;
  }
  public void setStreet(String street) {
      this.street = street;
  }
  public String getStreetnr() {
      return streetnr;
  }
  public void setStreetnr(String streetnr) {
      this.streetnr = streetnr;
  }
  public String getZipcode() {
      return zipcode;
  }
  public void setZipcode(String zipcode) {
      this.zipcode = zipcode;
  }
  public String getPlace() {
      return place;
  }
  public void setPlace(String place) {
      this.place = place;
  }
  </code></pre>
  
  <p>What can I do? Why there's always this error logged in RestKit: </p>
  
  <pre><code>Expected status code in (200-299), got 400" UserInfo=0x956e2f0 {NSLocalizedRecoverySuggestion=Unrecognized field "customer" (Class customer.model.Customer), not marked as ignorable
  </code></pre>
  
  <p>I don't have a field named customer.</p>
  
  <p>Here is my POST method:</p>
  
  <pre><code>@POST
  @Path("/insert")
  @Consumes(MediaType.APPLICATION_JSON)
  public Response insertCustomer(Customer customer) {
      String result = "Customer inserted " + customer.getLastname();
      customer.createEntity();
      return Response.status(201).type(MediaType.APPLICATION_JSON).entity(result).build();
  }
  </code></pre>
  
  <p>This is an example of a generated JSON object (Jackson), when a @GET method is called within my ios application.</p>
  
  <pre><code> {
  "appell": "Frau",
  "birthday": "1991-10-01T00:00:00+01:00",
  "customer_id": "3",
  "firstname": "Max",
  "lastname": "Mustermann",
  "place": "München",
  "street": "Einsteinweg",
  "streetnr": "19",
  "zipcode": "81858"
  </code></pre>
  
  <p>}</p>
  
  <p>And this is an example of the JSON object, when my ios application calls the showed @POST method:</p>
  
  <pre><code>{"customer":{"streetnr":"19",
   "zipcode":"81829",
   "customer_id":0,
   "place":"München",
   "appell":"Herr",
   "firstname":"Heinrich",
   "birthday":"1991-10-01T00:00:00+01:00",
   "lastname":"Maier",
   "street":"Lehrer-Wirth-Str.19"}}
  </code></pre>
  
  <p>I am a absolute newbie using restkit and jax-rs. </p>
  
  <p>I just added a @GET method for requesting xml format.
  Here you can see it:</p>
  
  <pre><code>@GET
  @Path("/listallcustomers")
  @Produces(MediaType.APPLICATION_XML)
  public ArrayList&lt;Customer&gt; showAllCustomers() {
      ArrayList&lt;Customer&gt; list = DBAccess.getInstance().getAllCustomers();
      return list;
  }
  </code></pre>
  
  <p>and this is the result:</p>
  
  <pre><code>&lt;customers&gt;
    &lt;customer&gt;
    &lt;appell&gt;Frau&lt;/appell&gt;
    &lt;birthday&gt;1991-10-01T00:00:00+01:00&lt;/birthday&gt;
    &lt;customer_id&gt;3&lt;/customer_id&gt;
    &lt;firstname&gt;Max&lt;/firstname&gt;
    &lt;lastname&gt;MUstermann&lt;/lastname&gt;
    &lt;place&gt;München&lt;/place&gt;
    &lt;street&gt;Einsteinstr.&lt;/street&gt;
    &lt;streetnr&gt;19&lt;/streetnr&gt;
    &lt;zipcode&gt;82838&lt;/zipcode&gt;
  &lt;/customer&gt;
    ...
  </code></pre>
  
  <p>My @GET method which creates a JSON object is the following:</p>
  
  <pre><code>@GET
  @Path("/listall")
  @Produces(MediaType.APPLICATION_JSON)
  public ArrayList&lt;Customer&gt; showAllJsonCustomers() {
      ArrayList&lt;Customer&gt; list = DBAccess.getInstance().getAllCustomers();
      return list;
  }
  </code></pre>
  
  <p>and this an example of a JSON object it creates:</p>
  
  <pre><code>{
  "lastname": "Müller",
  "customer_id": 6,
  "appell": "Herr",
  "firstname": "pupsi",
  "birthday": "1986-10-16",
  "street": "Lehrer-Wirth-Str",
  "streetnr": "19",
  "zipcode": "81829",
  "place": "München"
  },
  ...
  </code></pre>