title: JPA Unknown entity type Exception
body: <pre><code>@Entity
  @Table(name = "persons")    
  public class Person implements Serializable {
  
          @Id
          @GeneratedValue(strategy = GenerationType.IDENTITY)
          @Basic(optional = false)
          @Column(name = "id")
          private Integer id;
          @Basic(optional = false)
          @Enumerated(EnumType.STRING)
          @Column(name = "occupation")
          private Occupation occupation;
          @Basic(optional = false)
          @Column(name = "address")
          private String address;
      }
  </code></pre>
  
  <p>I am trying to persist this Object and I keep getting this Exception:</p>
  
  <p>Caused by: java.lang.IllegalArgumentException: Object: com.entity.Person(id[null] occupation[null] address["Toronto"]  is not a known Entity type.</p>
  
  <p>I tried to look up this Exception but the explanations are way to vague for me to understand. I am kind of new to JPA</p>
  
  <p>Can anyone please help me. </p>
  
  <p>P.S. I do have getters and setters</p>
  
  <p>Thanks in advance. </p>