Hibernate One-to-Many using Annotations

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Hibernate Annotation配置 one-to-many。

考虑以下 Student 和 Phone 实体。

一个Student可能有多个Phone，要模拟这种关系，我们需要三张表 STUDENT, PHONE 和 STUDENT_PHONE . 如下：

下面是Student和Phone的实体类：

Student.java

package org.aaron.hibernate.entity.one2many;import java.util.HashSet;import java.util.Set;import javax.persistence.CascadeType;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.JoinColumn;import javax.persistence.JoinColumns;import javax.persistence.JoinTable;import javax.persistence.OneToMany;import javax.persistence.Table;@Entity@Table(name = "STUDENT")public class Student {private long studentId;private String studentName;private Set<Phone> phones = new HashSet<Phone>();public Student() {}public Student(String studentName, Set<Phone> phones) {this.studentName = studentName;this.phones = phones;}@Id@GeneratedValue@Column(name = "STUDENT_ID")public long getStudentId() {return studentId;}public void setStudentId(long studentId) {this.studentId = studentId;}@Column(name = "STUDNET_NAME", nullable = false, length = 100)public String getStudentName() {return studentName;}public void setStudentName(String studentName) {this.studentName = studentName;}@OneToMany(cascade = CascadeType.ALL)@JoinTable(name = "STUDENT_PHONE", joinColumns = { @JoinColumn(name = "STUDENT_ID") }, inverseJoinColumns = { @JoinColumn(name = "PHONE_ID") })public Set<Phone> getPhones() {return phones;}public void setPhones(Set<Phone> phones) {this.phones = phones;}}

Phone.java

package org.aaron.hibernate.entity.one2many;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.Table;@Entity@Table(name = "PHONE")public class Phone {private long phoneId;private String phoneType;private String phoneNumber;public Phone() {}public Phone(String phoneType, String phoneNumber) {this.phoneType = phoneType;this.phoneNumber = phoneNumber;}@Id@GeneratedValue@Column(name = "PHONE_ID")public long getPhoneId() {return phoneId;}public void setPhoneId(long phoneId) {this.phoneId = phoneId;}@Column(name = "PHONE_TYPE", nullable = false, length = 10)public String getPhoneType() {return phoneType;}public void setPhoneType(String phoneType) {this.phoneType = phoneType;}@Column(name = "PHONE_NUMBER", nullable = false, length = 15)public String getPhoneNumber() {return phoneNumber;}public void setPhoneNumber(String phoneNumber) {this.phoneNumber = phoneNumber;}}

在Hibernate配置文件进行配置：

hibernate.cfg.xml

<?xml version="1.0" encoding="utf-8"?><!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"><hibernate-configuration><session-factory><property name="hibernate.connection.driver_class">com.microsoft.sqlserver.jdbc.SQLServerDriver</property><property name="hibernate.connection.password">test</property><property name="hibernate.connection.url">jdbc:sqlserver://192.168.1.168:1433;DatabaseName=hibernate</property><property name="hibernate.connection.username">test</property><property name="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</property><property name="show_sql">true</property><property name="hbm2ddl.auto">create</property><mapping class="org.aaron.hibernate.entity.one2many.Phone" /><mapping class="org.aaron.hibernate.entity.one2many.Student" /></session-factory></hibernate-configuration>

测试类：

Main.java

package org.aaron.hibernate.entity.one2many;import java.util.HashSet;import java.util.Set;import org.aaron.hibernate.util.HibernateUtil;import org.hibernate.HibernateException;import org.hibernate.Session;import org.hibernate.Transaction;public class Main {public static void main(String[] args) {Session session = HibernateUtil.getSessionFactory().openSession();Transaction transaction = null;try {transaction = session.beginTransaction();Set<Phone> phoneNumbers = new HashSet<Phone>();phoneNumbers.add(new Phone("house","32354353"));phoneNumbers.add(new Phone("mobile","9889343423"));Student student = new Student("Eswar", phoneNumbers);session.save(student);transaction.commit();} catch (HibernateException e) {transaction.rollback();e.printStackTrace();} finally {session.close();}}}

Okay。