如何使用JPA注釋映射一組字符串對象？

Question

@Entity
public class TestClass implements Serializable{
    private Integer id;
    private Set<String> mySet;

    @Id
    @GeneratedValue
    public Integer getId() {
        return id;
    }
    @OneToMany(cascade={CascadeType.ALL})
    public Set<String> getMySet() {
        return mySet;
    }
}

我收到以下錯誤。

Caused by: org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class: TestClass.mySet[java.lang.String]

或者如果我離開@OneToMany

org.hibernate.MappingException: Could not determine type for: java.util.Set, at table: test_class, for columns: [org.hibernate.mapping.Column(my_sets) ]

Answer 1

你會在這里找到一個相當不錯的答案。 列表規則也適用於集合。

Answer 2

哦，我必須這樣做。

@CollectionOfElements(targetElement = String.class)