I seem to have problems with mapping a List in Hibernate. In our project there a class Card with contains a class Answer with Answer c         
        
try
  @org.hibernate.annotations.CollectionOfElements(
        targetElement = java.lang.String.class
    )
    @JoinTable(
        name = "foo",
        joinColumns = @JoinColumn(name = "foo_id")
    )
    @org.hibernate.annotations.IndexColumn(
        name = "POSITION", base = 1
    )
    @Column(name = "baz", nullable = false)
    private List<String> arguments = new ArrayList<String>();
or see this detail example
Use @ElementCollection:
@ElementCollection
@CollectionTable(name="Nicknames", joinColumns=@JoinColumn(name="user_id"))
@Column(name="nickname")
public List<String> getNicknames() { ... } 
Source: 7.2.3. Collections of basic types and embeddable objects