6
我有一個休眠多對多關係的問題：當我從我的設置中刪除一個項目時，它不會在我的數據庫中刪除。我知道有很多類似的問題，但是我沒有通過閱讀來解決我的問題。休眠多對多刪除關係
我已經爲它寫了一個JUnit測試用例。我的聯想是建築物和用戶之間：
@Test
public void testBuildingManyToMany(){
//Create 2 buildings
Building building = createBuilding("b1");
Building building2 = createBuilding("b2");
//Create 1 user
User user = createUser("u1");
//Associate the 2 buildings to that user
user.getBuildings().add(building);
building.getUsers().add(user);
user.getBuildings().add(building2);
building2.getUsers().add(user);
userController.save(user);
user = userController.retrieve(user.getId());
Assert.assertEquals(2, user.getBuildings().size());//Test OK
//Test 1: remove 1 building from the list
user.getBuildings().remove(building);
building.getUsers().remove(user);
userController.save(user);
//Test 2: clear and add
//user.getBuildings().clear();
//user.getBuildings().add(building);
//userController.save(user);
//user = userController.retrieve(user.getId());
//Assert.assertEquals(1, user.getBuildings().size());
}
這是我得到的錯誤：
...
Hibernate: insert into building_useraccount (userid, buildingid) values (?, ?)
Hibernate: insert into building_useraccount (userid, buildingid) values (?, ?)
Hibernate: delete from building_useraccount where userid=? and buildingid=?
Hibernate: insert into building_useraccount (userid, buildingid) values (?, ?)
4113 [main] WARN org.hibernate.util.JDBCExceptionReporter - SQL Error: 23505, SQLState: 23505
4113 [main] ERROR org.hibernate.util.JDBCExceptionReporter - Unique index or primary key violation: "PRIMARY_KEY_23 ON PUBLIC.BUILDING_USERACCOUNT(BUILDINGID, USERID) VALUES (/* key:0 */ 201, 201)"; SQL statement:
insert into building_useraccount (userid, buildingid) values (?, ?) [23505-176]
當我評論「測試1」，並取消對「測試2」行，我去下面錯誤：
junit.framework.AssertionFailedError:
Expected :1
Actual :2
這裏是我的hbm.xml類：
<hibernate-mapping default-lazy="true">
<class name="my.model.pojo.Building" table="building">
<cache usage="read-write" />
<id name="id" column="id" type="java.lang.Long">
<generator class="sequence">
<param name="sequence">building_id_sequence</param>
</generator>
</id>
<property name="name" type="java.lang.String" column="name" not-null="true" />
...
<set name="users" cascade="none" lazy="true" inverse="true" table="building_useraccount">
<key column="buildingid" />
<many-to-many class="my.model.pojo.User" column="userid" />
</set>
</class>
</hibernate-mapping>
和
<hibernate-mapping default-lazy="true">
<class name="my.model.pojo.User" table="useraccount">
<cache usage="read-write" />
<id name="id" column="id" type="java.lang.Long">
<generator class="sequence">
<param name="sequence">useraccount_id_sequence</param>
</generator>
</id>
<property name="login" type="java.lang.String" column="login" not-null="true" unique="true" length="40" />
...
<set name="buildings" cascade="none" lazy="false" fetch="join" table="building_useraccount">
<key column="userid" />
<many-to-many class="my.model.pojo.Building" column="buildingid" />
</set>
</class>
</hibernate-mapping>
和類
public class User implements Serializable, Identifiable {
private static final long serialVersionUID = 1L;
private int hashCode;
private Long id;
private String login;
private Set<Building> buildings = new HashSet<Building>();
public boolean equals(Object value) {
if (value == this)
return true;
if (value == null || !(value instanceof User))
return false;
if (getId() != null && getId().equals(((User) value).getId()))
return true;
return super.equals(value);
}
public int hashCode() {
if (hashCode == 0) {
hashCode = (getId() == null) ? super.hashCode() : new HashCodeBuilder().append(getId()).toHashCode();
}
return hashCode;
}
/* Getter/Setter ... */
和
public class BuildingBase implements Serializable, Identifiable {
private static final long serialVersionUID = 1L;
private int hashCode;
private Long id;
private String name;
private Set<User> users = new HashSet<User>();
public boolean equals(Object value) {
if (value == this)
return true;
if (value == null || !(value instanceof Building))
return false;
if (getId() != null && getId().equals(((Building) value).getId()))
return true;
return super.equals(value);
}
public int hashCode() {
if (hashCode == 0) {
hashCode = (getId() == null) ? super.hashCode() : new HashCodeBuilder().append(getId()).toHashCode();
}
return hashCode;
}
/* Getter/Setter ... */
編輯：添加UserController的實施，對交易
@Transactional(readOnly = false, propagation = Propagation.REQUIRED)
public User save(User user) throws ServiceException {
validate(user);//Validation stuffs
return userDAO.update(user);
}
的userDAO的：
public class UserDAOImpl extends HibernateDAOImpl<User> implements UserDAO {
}
而且HibernateDAOImpl：
public class HibernateDAOImpl<T> implements DAO<T> {
public T update(T entity) {
return executeAndCreateSessionIfNeeded(new HibernateAction<T>() {
@Override
public T execute(Session session) {
return (T) session.merge(entity);
}
});
}
protected <E> E executeAndCreateSessionIfNeeded(HibernateAction<E> action) {
Session session = null;
try {
session = sessionFactory.getCurrentSession();
return executeAction(action, session);
} finally {
if (session != null) {
session.close();
}
}
}
}
請張貼userController.save'方法'實現。另外，交易界限是什麼？ –
我添加了一些實現。該交易工作得很好，因爲它在代碼中的任何地方都能成功使用。還要注意清除建築物（使用user.getBuildings（）。clear（））也可以工作並清空我的多對多數據庫表！只是刪除是奇怪的不工作... – Asterius