Hibernate多对多中间表有多个字段字段的注解配置方式（二）

情况二：如果中间表不仅仅是做关联用的，它里面包含了其他字段信息，仅仅靠多对多的关系是搞不定的。

解决方案：多对多的关系拆分为两个一对多！这时候三张表的Model都需要写。

我们知道，一对多的关系，一般都是在多的一方做配置。具体代码如下：

学生表

@Entity
@Table(name = "T_STUDENT")
@SequenceGenerator(name = "SEQ_STUDENT", sequenceName = "SEQ_STUDENT")
public class Student2 implements Serializable {
 private static final long serialVersionUID = 2524659555729848644L;
 private Long id;
 private String name;
 private Date birthday;
 private int sex;
 private String address;
 private Set<TeacherStudent> teacherStudentList;
 @Id
 @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ_STUDENT")
 @Column(name = "ID", nullable = false, precision = 22, scale = 0)
 public Long getId() {
  return id;
 }
 public void setId(Long id) {
  this.id = id;
 }
 @Column(name = "NAME")
 public String getName() {
  return name;
 }
 public void setName(String name) {
  this.name = name;
 }
 @Temporal(TemporalType.DATE)
 @Column(name = "BIRTHDAY")
 public Date getBirthday() {
  return birthday;
 }
 public void setBirthday(Date birthday) {
  this.birthday = birthday;
 }
 @Column(name = "sex")
 public int getSex() {
  return sex;
 }
 public void setSex(int sex) {
  this.sex = sex;
 }
 @Column(name = "address")
 public String getAddress() {
  return address;
 }
 public void setAddress(String address) {
  this.address = address;
 }
 @OneToMany(mappedBy="student",cascade=CascadeType.ALL)
 public Set<TeacherStudent> getTeacherStudentList() {
  return teacherStudentList;
 }
 public void setTeacherStudentList(Set<TeacherStudent> teacherStudentList) {
  this.teacherStudentList = teacherStudentList;
 }
}

教师表

@Entity

@Table(name = "T_TEACHER")

@SequenceGenerator(name = "SEQ_TEACHER", sequenceName = "SEQ_TEACHER")

public class Teacher2 implements Serializable {

 private static final long serialVersionUID = 2297316923535111793L;

 private Long id;

 private String name;

 private int sex;

 private Set<TeacherStudent> teacherStudentList;

 @Id

 @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ_TEACHER")

 @Column(name = "ID", nullable = false, precision = 22, scale = 0)

 public Long getId() {

  return id;

 }

 public void setId(Long id) {

  this.id = id;

 }

 @Column(name = "name")

 public String getName() {

  return name;

 }

 public void setName(String name) {

  this.name = name;

 }

 @Column(name = "sex")

 public int getSex() {

  return sex;

 }

 public void setSex(int sex) {

  this.sex = sex;

 }
 @OneToMany(mappedBy = "teacher",cascade=CascadeType.ALL)

 public Set<TeacherStudent> getTeacherStudentList() {

  return teacherStudentList;

 }

 public void setTeacherStudentList(Set<TeacherStudent> teacherStudentList) {

  this.teacherStudentList = teacherStudentList;

 }

}

中间表

@Entity

@Table(name = "T_TEACHERSTUDENT")

@SequenceGenerator(name = "SEQ_TEACHERSTUDENT", sequenceName = "SEQ_TEACHERSTUDENT")

public class TeacherStudent implements Serializable {

 private Long id;

 private Student2 student;

 private Teacher2 teacher;

 private String note1;

 private String note2;

 @Id

 @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ_TEACHERSTUDENT")

 @Column(name = "ID", nullable = false, precision = 22, scale = 0)

 public Long getId() {

  return id;

 }

 public void setId(Long id) {

  this.id = id;

 }

 @Column(name = "note1")

 public String getNote1() {

  return note1;

 }

 public void setNote1(String note1) {

  this.note1 = note1;

 }

 @Column(name = "note2")

 public String getNote2() {

  return note2;

 }

 public void setNote2(String note2) {

  this.note2 = note2;

 }
 @ManyToOne(cascade=CascadeType.ALL)
 @JoinColumn(name = "student_id", unique = true)

 public Student2 getStudent() {

  return student;

 }

 public void setStudent(Student2 student) {

  this.student = student;

 }

 @ManyToOne
 @JoinColumn(name = "teacher_id", unique = true)

 public Teacher2 getTeacher() {

  return teacher;

 }

 public void setTeacher(Teacher2 teacher) {

  this.teacher = teacher;

 }

}

hibernate.cfg.xml 引入对象

 <mapping class="com.dvn.li.model.Student2"/>
  <mapping class="com.dvn.li.model.Teacher2"/>
  <mapping class="com.dvn.li.model.TeacherStudent"/>

测试：

SessionFactory sessionFactory = null;
  Session session = null;
  try {
   sessionFactory = HibernateUtil.getSessionFactory();
   session = sessionFactory.getCurrentSession();
   session.beginTransaction();
   Student2 s = new Student2();
   s.setName("小猪");
   Teacher2 t = new Teacher2();
   t.setName("小李");
   TeacherStudent ts=new TeacherStudent();
   ts.setStudent(s);
   ts.setTeacher(t);
   ts.setNote1("以呀呀！！！");
   session.save(s);
   session.save(t);
   session.save(ts);
   session.getTransaction().commit();
  } catch (Exception e) {
   if (session != null) {
    session.getTransaction().rollback();
   }
  }

测试通过！

 

如果自己做测试，可以通过SchemaExport导入表结构

SchemaExport export = new SchemaExport(new AnnotationConfiguration()
    .configure());
  export.create(true, true);