Person,Student,Teacher各创建一个表,主键用一个中间表生成。
package com.bjsxt.hibernate;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Inheritance; import javax.persistence.InheritanceType; import javax.persistence.TableGenerator;@Entity
@Inheritance(strategy=InheritanceType.TABLE_PER_CLASS) @TableGenerator( name="t_gen", table="t_gen_table", pkColumnName="t_pk", valueColumnName="t_value", pkColumnValue="person_pk", initialValue=1, allocationSize=1 ) public class Person { private int id; private String name; @Id @GeneratedValue(generator="t_gen", strategy=GenerationType.TABLE) public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; }}
package com.bjsxt.hibernate;
import javax.persistence.Entity;
@Entity
public class Student extends Person { private int score;public int getScore() {
return score; }public void setScore(int score) {
this.score = score; } }
package com.bjsxt.hibernate;
import javax.persistence.Entity;
@Entity
public class Teacher extends Person { private String title;public String getTitle() {
return title; }public void setTitle(String title) {
this.title = title; }}
测试类:
package com.bjsxt.hibernate;
import java.util.Map;
import org.hibernate.Session;
import org.hibernate.SessionFactory; import org.hibernate.cfg.AnnotationConfiguration; import org.hibernate.tool.hbm2ddl.SchemaExport; import org.junit.AfterClass; import org.junit.BeforeClass; import org.junit.Test;public class HibernateORMappingTest {
private static SessionFactory sessionFactory; @BeforeClass public static void beforeClass() { new SchemaExport(new AnnotationConfiguration().configure()).create(false, true); sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory(); } @AfterClass public static void afterClass() { sessionFactory.close(); } @Test public void testSave() { Student s = new Student(); s.setName("s1"); s.setScore(80); Teacher t = new Teacher(); t.setName("t1"); t.setTitle("中级"); Session session = sessionFactory.openSession(); session.beginTransaction(); session.save(s); session.save(t); session.getTransaction().commit(); session.close(); } @Test public void testLoad() { testSave(); Session session = sessionFactory.openSession(); session.beginTransaction(); Student s = (Student)session.load(Student.class, 1); System.out.println(s.getScore()); Person p = (Person)session.load(Person.class, 2); System.out.println(p.getName()); session.getTransaction().commit(); session.close(); } @Test public void testSchemaExport() { new SchemaExport(new AnnotationConfiguration().configure()).create(false, true); } public static void main(String[] args) { beforeClass(); } }