title: Caused by: java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/JsonMappingException$Reference
body: <p>I am completely new to Java. I am trying to display JSON data, for that I have decided to go for Jackson library. But I am getting the Error.</p>
  
  <p>I am using </p>
  
  <pre><code>jackson-annotations-2.3.0.jar
  jackson-core-2.4.2.jar
  jackson-databind-2.4.2.jar
  </code></pre>
  
  <p>This is my Object and in this I have one dependency "tnStudentLocLog"</p>
  
  <pre><code>public class Student implements java.io.Serializable, WorkItem {
  
      private int studentId;
      private Date date;
      private Date startTime;
      private Date endtime;
      private int room;
      private Set tnStudentLocLog;
  
      public Student() {
      }
  
      public Student(int studentId,Date date, int room, Date startTime, Date endtime) {
          this.studentId = studentId;
          this.date = date;
          this.room = room;
          this.startTime = startTime;
          this.endtime = endtime;
      }
  }
  </code></pre>
  
  <p><strong>UserController class:</strong></p>
  
  <pre><code> @Controller
  @RequestMapping(value="/students")
  public class StudentController {
  
  
      private static Logger logger = Logger.getLogger( StudentController.class);
  
  
      private StudentManagerDelegate studentDelegate;  
  
  
      public StudentController() throws Exception
      {
          studentDelegate= new StudentManagerDelegate(ServiceType.LOCAL);
      }
      /********* GET ALL STUDENTS  ************/
      @RequestMapping(method=RequestMethod.GET)
      @ResponseStatus(HttpStatus.OK)
      public @ResponseBody SuccessResponse&lt;List&lt;Student&gt;&gt; getAllStudents() throws Exception {
          Map&lt;String,List&lt;Student&gt;&gt; studentsMap = new HashMap&lt;String,List&lt;Student&gt;&gt;();
          SuccessResponse&lt;List&lt;Student&gt;&gt; resp = new SuccessResponse&lt;List&lt;Student&gt;&gt;();
          resp.list = studentDelegate.load();
          return resp;
      }
  </code></pre>
  
  <p>Here, I am getting the correct result. But, "studentId":2 is looping itself like below</p>
  
  <pre><code>     {"max":"30","list":[{"studentId":2,"date":1339327730000,"startTime":1339327806000,"endtime":1339329470000,"room":0,"tnStudentLocLog":
  [{"id":"studentId":2,"inTime":1339327872000},"sequenceId":2,"outTime":1339327967000,"Student":{"studentId":2,"date":1339327730000,"startTime":1339327806000,"endtime":1339329470000,"tnStudentLocLog":[{"id":{"studentId":2,"room":10,"inTime":1339327872000},"sequenceId":2,"outTime":1339327967000,"Student":{"studentId":2,"date":1339327730000,"startTime":1339327806000,"endtime":1339329470000,"tnStudentLocLog":[{"id":.......
  </code></pre>
  
  <p>But, In the URL when I enter "/students/4". It is displaying correctly. 
  I don't know what exactly happening. I saw many posts, they are changing versions of Jackson core, annotations. But, that is not working in my case.</p>
  
  <p>Thanks in advance for your help.</p>