title: Error saving an object for a column with many to one relation
body: <p>This is my school entity.</p>
  <pre><code>@Entity
  @JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = &quot;id&quot;)
  
  public class School{
  
      @Id
      @GeneratedValue(strategy = GenerationType.IDENTITY)
      @Column
      private Long id;
  
      @Column
      private String name;
  
      @JsonManagedReference
      @OneToMany(mappedBy = &quot;school&quot;, cascade = CascadeType.ALL)
      private Set&lt;Teacher&gt; Teachers= new HashSet&lt;&gt;();
  
  //constructor, getter and setter
  </code></pre>
  <p>This is my teacher class</p>
  <pre><code>@Entity
  @JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = &quot;id&quot;)
  
  public class Teacher{
  
      @Id
      @GeneratedValue(strategy = GenerationType.IDENTITY)
      @Column
      private Long id;
  
      @Column
      private String userId;
  
      @ManyToOne
      @JoinColumn(name = &quot;SCHOOL_ID&quot;)
      @JsonProperty(&quot;schoolId&quot;)
      @JsonBackReference
      private School school;
  
  //constructor, getter and setter
  </code></pre>
  <p>My teacher controller looks like this</p>
  <pre><code>    @ApiOperation(value = &quot;Create new teacher&quot;, response = Teacher.class)
      @ApiParam
      @RequestMapping(value = &quot;/teacher&quot;, method = RequestMethod.POST)
      public Teacher createTeacher(@RequestBody Teacher t) {      
          return teacherService.saveTeacher(t);
      }
  </code></pre>
  <p>My service which just calls the CrudRepository save method.</p>
  <pre><code>    public Teacher saveTeacher(Teacher t) {
          return teacherRepository.save(t);
  
      }
  </code></pre>
  <p>This is how my JSON looks like when creating a teacher. A school object with id = 1 exists in my db</p>
  <pre><code>{
      &quot;userId&quot;:&quot;jDoe&quot;,
      &quot;schoolId&quot;:1
  }
  </code></pre>
  <p>This is the error I get</p>
  <pre><code> Could not resolve parameter [0] in public com.lace.schoolApp.model.Teacher com.lace.schoolApp.controller.TeacherController.createTeacher(com.lace.schoolApp.model.Teacher): JSON parse error: Unresolved forward references for: ; nested exception is com.fasterxml.jackson.databind.deser.UnresolvedForwardReference: Unresolved forward references for: 
   at [Source: (PushbackInputStream); line: 7, column: 1]Object id [1] (for `com.lace.schoolApp.model.School`) at [Source: (PushbackInputStream); line: 5, column: 16].
  2021-02-10 17:04:11.959  WARN 11628 --- [nio-8090-exec-1] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Unresolved forward references for: ; nested exception is com.fasterxml.jackson.databind.deser.UnresolvedForwardReference: Unresolved forward references for: 
   at [Source: (PushbackInputStream); line: 7, column: 1]Object id [1] (for `com.lace.schoolApp.model.School`) at [Source: (PushbackInputStream); line: 5, column: 16].]
  </code></pre>