JPA-Hibernate 多对多关系映射

（1）实体类

@Entity
@Table(name = "erp_role")
public class Role {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String name;
    private String description;
    @ManyToMany
    @JoinTable(name = "erp_role_priv", joinColumns = @JoinColumn(name = "roleid"), inverseJoinColumns = @JoinColumn(name = "privid"))
    private Set<Priv> privs = new HashSet<>();
    //省略get和set方法
}
 1 @Entity
 2 @Table(name = "erp_priv")
 3 public class Priv {
 4     @Id
 5     private Integer id;
 6     private String name;
 7     private String link;
 8     private Integer parentid;
 9     private String icon;
10     //省略get和set方法
11 }

（2）测试类

 1 public class RoleTest {
 2     private static EntityManagerFactory emf;
 3     private EntityManager em;
 4     private EntityTransaction tx;
 5 
 6     @BeforeClass
 7     public static void init() {
 8         emf = Persistence.createEntityManagerFactory("jpa");
 9     }
10 
11     @AfterClass
12     public static void destory() {
13         emf = null;
14     }
15 
16     @Before
17     public void setUp() {
18         em = emf.createEntityManager();
19         tx = em.getTransaction();
20         tx.begin();
21     }
22 
23     @After
24     public void tearDown() {
25         tx.commit();
26         em.close();
27     }
28 
29     @Test
30     public void testAddRole() {
31         Role role = new Role();
32         role.setName("新增角色");
33         role.setDescription("新增角色描述");
34 
35         role.getPrivs().add(em.getReference(Priv.class, 23));
36         role.getPrivs().add(em.getReference(Priv.class, 24));
37 
38         em.persist(role);
39     }
40 
41     @Test
42     public void testDeleteRole() {
43         Role role = em.find(Role.class, 5);
44         em.remove(role);
45     }
46 
47     @Test
48     public void testGetRoles() {
49         TypedQuery<Role> query = em.createQuery("from Role", Role.class);
50         query.getResultList().forEach(role -> System.out.println(role.getPrivs()));
51     }
52 }

 

posted @ 2018-02-01 10:13  迷途_小羔羊  阅读(193)  评论(0)  编辑  收藏  举报