JPAにおける多対多の構成
3575 ワード
学生と先生を例にとると
学生クラス:
Teacherクラスの構成:
学生クラス:
package com.dimples.dao;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
import org.hibernate.annotations.GenericGenerator;
@Entity
@Table(name="student")
public class Student {
@Id
@GenericGenerator(name="uuid",strategy="uuid")
@GeneratedValue(generator="uuid")
@Column(name="id")
private String id;
@Column(name="name")
private String name;
@Column(name="address")
private String address;
@ManyToMany
@JoinTable(name="teacher_student", //
// ,
joinColumns= {@JoinColumn(name="student_id",referencedColumnName="id")},
// ,
inverseJoinColumns= {@JoinColumn(name="teacher_id",referencedColumnName="id")}
)
private Set teachers = new HashSet(0);
public Set getTeachers() {
return teachers;
}
public void setTeachers(Set teachers) {
this.teachers = teachers;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "Student [id=" + id + ", name=" + name + ", address=" + address + "]";
}
Teacherクラスの構成:
package com.dimples.dao;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
import org.hibernate.annotations.GenericGenerator;
@Entity
@Table(name="teacher")
public class Teacher {
@Id
@GenericGenerator(name="uuid",strategy="uuid")
@GeneratedValue(generator="uuid")
@Column(name="id")
private String id;
@Column(name="name")
private String name;
@Column(name="shoolName")
private String shoolName;
@Column(name="phone")
private String phone;
@ManyToMany(mappedBy="teachers") // mappedBy, 。
private Set students = new HashSet(0);
public Set getStudents() {
return students;
}
public void setStudents(Set students) {
this.students = students;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getShoolName() {
return shoolName;
}
public void setShoolName(String shoolName) {
this.shoolName = shoolName;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
@Override
public String toString() {
return "Teacher [id=" + id + ", name=" + name + ", shoolName=" + shoolName + ", phone=" + phone + "]";
}
}