title: Spring 4.1.1 RELEASE and @ResponseBody return HTTP 406
body: <p>I am using @ResponseBody to return Json object in Spring MVC. It works as expected on release 4.0.7 and 3.2.11, but it returns HTTP status 406 when I try to use the latest Spring release 4.1.1(as of 10/16) with no any other configuration changes. Is this considered a bug or the 4.1.1 requires different configuration?</p>
  
  <p>the latest jackson jar is already in the classpath</p>
  
  <pre><code>&lt;dependency&gt;
      &lt;groupId&gt;org.codehaus.jackson&lt;/groupId&gt;
      &lt;artifactId&gt;jackson-mapper-asl&lt;/artifactId&gt;
      &lt;version&gt;1.9.13&lt;/version&gt;
  &lt;/dependency&gt;
  </code></pre>
  
  <p>The example on the Spring <a href="http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#mvc-ann-responsebody">document</a> works fine</p>
  
  <pre><code>@RequestMapping(value = "/something", method = RequestMethod.PUT)
  @ResponseBody
  public String helloWorld() {
    return "Hello World";
  }
  </code></pre>
  
  <p>when the return type is String. The problem happens when the return type is a POJO.</p>