title: spring, Jackson, Fasterxml Annotations not work
body: <p>I'm using jackson and fasterxml. But i can annotate anything an there's no reaction on the annotation. The java Object should be parse to a json object an then with the springresttemplate it should be posted.
  I always get a JsonMappingException, which says that i have a null object reference. But the code is annotatet with @JsonIgnore on this Field.</p>
  
  <p>Here's the JavaClass
      import com.fasterxml.jackson.annotation.JsonIgnore;
  import com.fasterxml.jackson.annotation.JsonIgnoreProperties;</p>
  
  <pre><code>@JsonIgnoreProperties(ignoreUnknown = true)
  public class SkillGruppeTO extends NamedBaseObject implements Serializable {
  
  private static final long serialVersionUID = 1L;
  @JsonIgnore
  private RolleTO rolleToAssign;
  
  public SkillGruppeTO() {
      super();
  }
  @JsonIgnore
  public SkillGruppeTO(Long id, String name) {
      this(id, name, null);
  }
  @JsonIgnore
  public SkillGruppeTO(long id, String skillGruppeName, RolleTO rolleToAssign) {
      this.id = id;
      this.name = skillGruppeName;
      this.rolleToAssign = rolleToAssign;
  }
  
  @JsonIgnore
  public RolleTO getRolleToAssign() {
      return rolleToAssign;
  }
  @JsonIgnore
  public void setRolleToAssign(RolleTO rolle) {
      this.rolleToAssign = rolle;
  }
  }
  </code></pre>
  
  <p>The call</p>
  
  <pre><code>  final String formatedUrl = BASE_URL + "auspraegungen";
      JSONObject jsonObject = new JSONObject();
      jsonObject.put("auspraegungen", auspraegungTOs);
      HttpHeaders headers = new HttpHeaders();
      headers.setContentType(MediaType.APPLICATION_JSON);
      HttpEntity request = new HttpEntity(jsonObject, headers);
      RestTemplate restTemplate = new RestTemplate();
  
     MitarbeiterTO[] mitarbeiterArray =  restTemplate.postForObject(formatedUrl, request, MitarbeiterTO[].class, MITARBEITER_METHOD);
      return Arrays.asList(mitarbeiterArray);
  </code></pre>
  
  <p>And that is the stacktrace</p>
  
  <pre><code>org.springframework.http.converter.HttpMessageNotWritableException: Could not write content: null object (through reference chain: net.sf.json.JSONObject["auspraegungen"]-&gt;net.sf.json.JSONArray[0]-&gt;net.sf.json.JSONObject["skill"]-&gt;net.sf.json.JSONObject["gruppe"]-&gt;net.sf.json.JSONObject["rolleToAssign"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: null object (through reference chain: net.sf.json.JSONObject["auspraegungen"]-&gt;net.sf.json.JSONArray[0]-&gt;net.sf.json.JSONObject["skill"]-&gt;net.sf.json.JSONObject["gruppe"]-&gt;net.sf.json.JSONObject["rolleToAssign"])
  at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:238)
  at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:208)
  at org.springframework.web.client.RestTemplate$HttpEntityRequestCallback.doWithRequest(RestTemplate.java:769)
  at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:558)
  at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:521)
  at org.springframework.web.client.RestTemplate.postForObject(RestTemplate.java:321)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:94)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:55)
  at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
  at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
  at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
  at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
  at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
  at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
  at org.junit.rules.ExpectedException$ExpectedExceptionStatement.evaluate(ExpectedException.java:168)
  at org.junit.rules.RunRules.evaluate(RunRules.java:20)
  at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
  at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
  at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
  at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
  at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
  at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
  at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
  at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
  at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
  at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:211)
  at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:94)
  at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
  Caused by: com.fasterxml.jackson.databind.JsonMappingException: null object (through reference chain: net.sf.json.JSONObject["auspraegungen"]-&gt;net.sf.json.JSONArray[0]-&gt;net.sf.json.JSONObject["skill"]-&gt;net.sf.json.JSONObject["gruppe"]-&gt;net.sf.json.JSONObject["rolleToAssign"])
  at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:210)
  at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:177)
  at com.fasterxml.jackson.databind.ser.std.StdSerializer.wrapAndThrow(StdSerializer.java:187)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:495)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:412)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:27)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:491)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:412)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:27)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:491)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:412)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:27)
  at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:117)
  at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:23)
  at com.fasterxml.jackson.databind.ser.std.AsArraySerializerBase.serialize(AsArraySerializerBase.java:183)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:491)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:412)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:27)
  at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:114)
  at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:1887)
  at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:231)
  ... 37 more
  Caused by: net.sf.json.JSONException: null object
  at net.sf.json.JSONObject.verifyIsNull(JSONObject.java:2875)
  at net.sf.json.JSONObject.isEmpty(JSONObject.java:2232)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:399)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:27)
  at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:491)
  ... 54 more
  </code></pre>