Hibernate继承映射(2)

基本的和上次是一样的,变是的配置文件

1.Extend2.hbm.xml配置文件

<hibernate-mapping package="com.sing.hibernate.entity"><class name="Animal2" table="s_animal2"><id name="id" column="a_id"><generator class="sequence"><param name="sequence">a_animal_seq</param></generator></id><property name="name" column="a_name" /><property name="sex" column="a_sex" /><!-- 生成单独生成一张表 --><joined-subclass name="Pig2" table="s_pig2"><!-- p_id会生成为主键，并且以外键引用Animal2的a_id --><key column="p_id" /><property name="weight" column="p_weight" /></joined-subclass><joined-subclass name="Bird2" table="s_bird2"><!-- p_id会生成为主键，并且以外键引用Animal2的a_id --><key column="b_id" /><property name="height" column="b_height" /></joined-subclass></class></hibernate-mapping>

 

2.测试类

@Testpublic void save() {Session session = HibernateUtil.getSession();try {session.beginTransaction();Pig2 pig = new Pig2();pig.setName("猪八戒");pig.setSex('女');pig.setWeight(100);Bird2 bird = new Bird2();bird.setName("小鸟");bird.setSex('男');bird.setHeight(500);session.save(pig);session.save(bird);session.getTransaction().commit();} catch (Exception e) {session.getTransaction().rollback();} finally {HibernateUtil.closeSession();}}@Testpublic void load() {Session session = HibernateUtil.getSession();try {session.beginTransaction();Pig2 pig2 = (Pig2) session.load(Pig2.class, 1);System.out.println(pig2.getName());System.out.println(pig2.getWeight());session.getTransaction().commit();} catch (Exception e) {session.getTransaction().rollback();} finally {HibernateUtil.closeSession();}}@Testpublic void load2() {Session session = HibernateUtil.getSession();try {session.beginTransaction();Animal2 animal2 = (Animal2) session.get(Animal2.class, 1);System.out.println(animal2.getName());// 因为load方法加载,Animal返回的是一个代理类对象// load默认是不支持多态查询,可以采用把<class>标签上面的lazy属性设置为false即可// get直接支持多态查询if (animal2 instanceof Pig2) {System.out.println("-------animal--pig" + animal2.getClass());} else {System.out.println("-------animal--bird");}session.getTransaction().commit();} catch (Exception e) {session.getTransaction().rollback();} finally {HibernateUtil.closeSession();}}@Testpublic void load3() {Session session = HibernateUtil.getSession();try {session.beginTransaction();List<Animal2> animal2s = session.createQuery("from Animal2").list();for (Animal2 animal : animal2s) {System.out.println("-------animal--pig" + animal.getClass());}session.getTransaction().commit();} catch (Exception e) {session.getTransaction().rollback();} finally {HibernateUtil.closeSession();}}