資訊專(zhuān)欄INFORMATION COLUMN
摘要：時(shí)間年月日星期二說(shuō)明本文部分內(nèi)容均來(lái)自慕課網(wǎng)。文件如下在目錄下，創(chuàng)建文件指定映射文件的路徑注解映射實(shí)體類(lèi)可選，對(duì)應(yīng)數(shù)據(jù)庫(kù)中的一個(gè)表。
時(shí)間：2017年07月11日星期二
說(shuō)明：本文部分內(nèi)容均來(lái)自慕課網(wǎng)。@慕課網(wǎng)：http://www.imooc.com
教學(xué)源碼：無(wú)
學(xué)習(xí)源碼：https://github.com/zccodere/s...
本章簡(jiǎn)介
Hibernate注解簡(jiǎn)介 JPA與Hibernate的關(guān)系 Hibernate注解分類(lèi) @Entity @Table @Embeddable schema與catalog
Hibernate注解簡(jiǎn)介
使用注解的目的：為了簡(jiǎn)化繁瑣的ORM映射文件（*.hbm）的配置
JPA與Hibernate的關(guān)系
什么是JPA
全稱(chēng)Java Persistence API
JPA注解是JavaEE的規(guī)范和標(biāo)準(zhǔn)
JPA和Hibernate的關(guān)系：
JPA是標(biāo)準(zhǔn)接口
Hibernate是實(shí)現(xiàn)，但是其功能是JPA的超集
Hibernate如何實(shí)現(xiàn)與JPA的關(guān)系
通過(guò)hibernate-annotation
hibernate-entitymanager
hibernate-core三個(gè)組件來(lái)實(shí)現(xiàn)
一般在實(shí)際開(kāi)發(fā)中，優(yōu)先考慮使用JPA注解
這樣更有利于程序的移植和擴(kuò)展
Hibernate注解的分類(lèi)
類(lèi)級(jí)別注解 屬性級(jí)別注解 映射關(guān)系注解
類(lèi)級(jí)別注解
@Entity：表示一個(gè)實(shí)體，一個(gè)實(shí)體對(duì)應(yīng)數(shù)據(jù)庫(kù)一張表 @Table：配置表的屬性 @Embeddable：表示當(dāng)前類(lèi)是一個(gè)嵌入類(lèi)1-2 準(zhǔn)備工作
回顧hibernate.cfg.xml
創(chuàng)建一個(gè)名為hibernateca的maven項(xiàng)目，并添加相關(guān)依賴(lài)。POM文件如下
4.0.0 com.myimooc hibernateca 0.0.1-SNAPSHOT jar hibernateca http://maven.apache.org UTF-8 UTF-8 org.hibernate hibernate-core 4.2.4.Final mysql mysql-connector-java 5.1.38 junit junit 4.10 test org.apache.maven.plugins maven-compiler-plugin 1.8 1.8
在src/main/ resources目錄下，創(chuàng)建hibernate.cfg.xml文件
1-3 @Entity注解org.hibernate.dialect.MySQLDialect com.mysql.jdbc.Driver root root true update
@Entity
@Entity：映射實(shí)體類(lèi) @Entity(name=”tableName”) name：可選，對(duì)應(yīng)數(shù)據(jù)庫(kù)中的一個(gè)表。若表名與實(shí)體類(lèi)名相同，則可以省略 注意：使用@Entity時(shí)必須指定實(shí)體類(lèi)的主鍵屬性
代碼演示
1.編寫(xiě)Students實(shí)體類(lèi)
package com.myimooc.hibernateca.entity;
import java.util.Date;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
/**
* 學(xué)生實(shí)體類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
//JPA注解
@Entity(name="t_students")
public class Students {
/** 學(xué)號(hào) */
@Id
private Integer sid;
/** 姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專(zhuān)業(yè) */
private String major;
@Override
public String toString() {
return "Students [sid=" + sid + ", sname=" + sname + ", gender=" + gender + ", birthday=" + birthday
+ ", major=" + major + "]";
}
public Students() {
super();
}
public Students(Integer sid, String sname, String gender, Date birthday, String major) {
super();
this.sid = sid;
this.sname = sname;
this.gender = gender;
this.birthday = birthday;
this.major = major;
this.address = address;
}
public Integer getSid() {
return sid;
}
public void setSid(Integer sid) {
this.sid = sid;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
}
2.配置映射
3.編寫(xiě)StudentTest測(cè)試類(lèi)
package com.myimooc.hibernateca.entity;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;
/**
* 單元測(cè)試類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
public class StudentsTest {
@Test
public void schemaExportTest(){
// 創(chuàng)建hibernate配置對(duì)象
Configuration config = new Configuration().configure();
// 創(chuàng)建服務(wù)注冊(cè)對(duì)象
ServiceRegistry ServiceRegistry = new ServiceRegistryBuilder()
.applySettings(config.getProperties()).buildServiceRegistry();
// 生成sessionFactory
@SuppressWarnings("unused")
SessionFactory sessionFactory = config.buildSessionFactory(ServiceRegistry);
SchemaExport export = new SchemaExport(config);
export.create(true, true);
}
}
1-4 @Table注解
@Table
@Table(name=””,catalog=””,schema=””) @Entity配置使用，只能標(biāo)注在實(shí)體的class定義處，表示實(shí)體對(duì)應(yīng)的數(shù)據(jù)庫(kù)表的信息 name：可選，映射表的名稱(chēng)，默認(rèn)表名和實(shí)體名稱(chēng)一致，只有在不一致的情況下才需要指定表名 catalog：可選，表示目錄Catalog名稱(chēng)，默認(rèn)為Catalog(“”) schema：可選，表示模式Schema名稱(chēng)，默認(rèn)為Schema(“”)
schema與catalog示意圖
schema與catalog
從實(shí)現(xiàn)的角度來(lái)看，各種數(shù)據(jù)庫(kù)系統(tǒng)對(duì)Catalog和Schema的支持和實(shí)現(xiàn)方式千差萬(wàn)別的
供應(yīng)商的支持和實(shí)現(xiàn)
代碼演示，修改Student類(lèi)如下
package com.myimooc.hibernateca.entity;
import java.util.Date;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
/**
* 學(xué)生實(shí)體類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
//JPA注解
//@Entity(name="t_students")
@Entity
@Table(name="t_students",schema="hibernatemtm")
public class Students {
/** 學(xué)號(hào) */
@Id
private Integer sid;
/** 姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專(zhuān)業(yè) */
private String major;
@Override
public String toString() {
return "Students [sid=" + sid + ", sname=" + sname + ", gender=" + gender + ", birthday=" + birthday
+ ", major=" + major + "]";
}
public Students() {
super();
}
public Students(Integer sid, String sname, String gender, Date birthday, String major) {
super();
this.sid = sid;
this.sname = sname;
this.gender = gender;
this.birthday = birthday;
this.major = major;
}
public Integer getSid() {
return sid;
}
public void setSid(Integer sid) {
this.sid = sid;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
}
1-5 @Embeddable注解
@Embeddable
@Embeddable表示一個(gè)非Entity類(lèi)可以嵌入到另一個(gè)Entity類(lèi)中作為屬性而存在
代碼演示
1.編寫(xiě)Address類(lèi)
package com.myimooc.hibernateca.entity;
import javax.persistence.Embeddable;
/**
* 地址類(lèi)（嵌入類(lèi)）
* @author ZhangCheng on 2017-07-12
*
*/
// 表示是一個(gè)嵌入類(lèi)，這個(gè)類(lèi)的對(duì)象在另一個(gè)實(shí)體類(lèi)中充當(dāng)屬性
@Embeddable
public class Address {
/** 郵編 */
private String postCode;
/** 地址 */
private String address;
/** 聯(lián)系電話 */
private String phone;
@Override
public String toString() {
return "Address [postCode=" + postCode + ", address=" + address + ", phone=" + phone + "]";
}
public Address() {
}
public Address(String postCode, String address, String phone) {
this.postCode = postCode;
this.address = address;
this.phone = phone;
}
public String getPostCode() {
return postCode;
}
public void setPostCode(String postCode) {
this.postCode = postCode;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
}
2.修改Student類(lèi)如下
package com.myimooc.hibernateca.entity;
import java.util.Date;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
/**
* 學(xué)生實(shí)體類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
//JPA注解
//@Entity(name="t_students")
@Entity
@Table(name="t_students",schema="hibernatemtm")
public class Students {
/** 學(xué)號(hào) */
@Id
private Integer sid;
/** 姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專(zhuān)業(yè) */
private String major;
/** 地址 */
private Address address;
@Override
public String toString() {
return "Students [sid=" + sid + ", sname=" + sname + ", gender=" + gender + ", birthday=" + birthday
+ ", major=" + major + "]";
}
public Students() {
super();
}
public Students(Integer sid, String sname, String gender, Date birthday, String major,Address address) {
super();
this.sid = sid;
this.sname = sname;
this.gender = gender;
this.birthday = birthday;
this.major = major;
this.address = address;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public Integer getSid() {
return sid;
}
public void setSid(Integer sid) {
this.sid = sid;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
}
第二章：屬性級(jí)別注解
2-1 本章簡(jiǎn)介
Hibernate屬性級(jí)別注解
添加方式：寫(xiě)在屬性字段方面 或 寫(xiě)在屬性的get訪問(wèn)器的上面 @Id -@SequenceGenerator @GeneratedValue @Column @Embedded @EmbeddedId -@Lob -@Version -@Basic @Transient2-2 @Id注解
@Id
@Id：必須，定義了映射到數(shù)據(jù)庫(kù)表的主鍵的屬性， 一個(gè)實(shí)體類(lèi)可以有一個(gè)或者多個(gè)屬性被映射為主鍵， 可置于主鍵屬性或者get方法前 注意：如果有多個(gè)屬性定義為主鍵屬性， 該實(shí)體類(lèi)必須實(shí)現(xiàn)serializable接口
拷貝hibernateca項(xiàng)目，重命名為hibernateaa，POM與Hibernate配置文件均相同
2-3 @GeneratedValue注解（一）@GeneratedValue
@GeneratedValue(strategy=GenerationType,generator=””)
可選，用戶(hù)定義主鍵生成策略
strategy表示主鍵生成策略，取值有
GenerationType.AUTO:根據(jù)底層數(shù)據(jù)庫(kù)自動(dòng)選擇（默認(rèn)）
GenerationType.INDENTITY：根據(jù)數(shù)據(jù)庫(kù)的Identity字段生成
GenerationType.SEQUENCE：使用Sequence來(lái)決定主鍵的取值
GenerationType.TABLE：使用指定表來(lái)決定主鍵取值，結(jié)合@TableGenerator使用
使用示例
2-4 @GeneratedValue注解（二）代碼演示
1.修改Students類(lèi)
package com.myimooc.hibernateaa.entity;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Embedded;
import javax.persistence.EmbeddedId;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Transient;
import org.hibernate.annotations.GenericGenerator;
/**
* 學(xué)生實(shí)體類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
@Entity
@Table(name="t_students",schema="hibernatemtm")
public class Students {
/** 學(xué)號(hào) */
/* 方式一：使用自動(dòng)生成主鍵
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private Integer sid;
*/
/* 方式二：使用手工賦值方式生成主鍵
@Id
@GeneratedValue(generator="sid")
@GenericGenerator(name="sid",strategy="assigned")//
@Column(length=8)
private String sid;
*/
/* 方式三：使用復(fù)合主鍵 */
@EmbeddedId
private StudentsPK pk;
/** 姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專(zhuān)業(yè) */
private String major;
/** 薪水 */
@Transient // 表示該屬性不會(huì)被ORM映射到表里的字段
private double salary;
/** 地址 */
@Embedded
private Address address;
@Override
public String toString() {
return "Students [pk=" + pk + ", sname=" + sname + ", gender=" + gender + ", birthday=" + birthday + ", major="
+ major + ", salary=" + salary + ", address=" + address + "]";
}
public Students() {
super();
}
public Students(StudentsPK pk, String sname, String gender, Date birthday, String major,Address address) {
super();
this.pk = pk;
this.sname = sname;
this.gender = gender;
this.birthday = birthday;
this.major = major;
this.address = address;
}
public Students(StudentsPK pk, String sname, String gender, Date birthday, String major, double salary,
Address address) {
super();
this.pk = pk;
this.sname = sname;
this.gender = gender;
this.birthday = birthday;
this.major = major;
this.salary = salary;
this.address = address;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public StudentsPK getPk() {
return pk;
}
public void setPk(StudentsPK pk) {
this.pk = pk;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
}
2-5 @GeneratedValue注解（三）
代碼演示
1.修改StudentsTest類(lèi)
package com.myimooc.hibernateaa.entity;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Before;
import org.junit.Test;
/**
* 單元測(cè)試類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
public void schemaExportTest(){
// 創(chuàng)建hibernate配置對(duì)象
Configuration config = new Configuration().configure();
// 創(chuàng)建服務(wù)注冊(cè)對(duì)象
ServiceRegistry ServiceRegistry = new ServiceRegistryBuilder()
.applySettings(config.getProperties()).buildServiceRegistry();
// 生成sessionFactory
sessionFactory = config.buildSessionFactory(ServiceRegistry);
// SchemaExport export = new SchemaExport(config);
// export.create(true, true);
}
@Test
public void addStudents(){
// 創(chuàng)建會(huì)話
Session session = sessionFactory.getCurrentSession();
// 創(chuàng)建事務(wù)
Transaction tx = session.beginTransaction();
// 創(chuàng)建一個(gè)學(xué)生對(duì)象
Address address = new Address("700005","湖北武當(dāng)山","18991167346");
// Students s = new Students("S0000002","張三豐","男",new Date(),"太極拳",address);
//
// session.save(s);
tx.commit();
}
@Test
public void addStudentsByPk(){
// 創(chuàng)建會(huì)話
Session session = sessionFactory.getCurrentSession();
// 創(chuàng)建事務(wù)
Transaction tx = session.beginTransaction();
// 創(chuàng)建一個(gè)學(xué)生對(duì)象
Address address = new Address("700005","湖北武當(dāng)山","18991167346");
// 創(chuàng)建學(xué)生主鍵對(duì)象
StudentsPK pk = new StudentsPK();
pk.setId("123456789012345678");
pk.setSid("1235241231");
Students s = new Students(pk,"張三豐","男",new Date(),"太極拳",address);
session.save(s);
tx.commit();
}
}
2-6 @Column注解
@Column
@Column：可將屬性映射到列，使用該注解來(lái)覆蓋默認(rèn)值 @Column描述了數(shù)據(jù)庫(kù)表中該字段的詳細(xì)定義 這對(duì)于根據(jù)JPA注解生成數(shù)據(jù)庫(kù)表結(jié)構(gòu)的工具非常有作用
常用屬性
name：可選，表示數(shù)據(jù)庫(kù)表中該字段的名稱(chēng)，默認(rèn)與屬性名稱(chēng)一致
nullable：可選，表示該字段是否允許為null，默認(rèn)為true
unique：可選，表示該字段是否是唯一標(biāo)識(shí)，默認(rèn)為false
length：可選，表示該字段的大小，僅對(duì)String類(lèi)型的字段有效，默認(rèn)為255
（如果是主鍵不能使用默認(rèn)值）
insertable：可選，表示在ORM框架執(zhí)行插入操作時(shí)，該字段是否應(yīng)出現(xiàn)INSERT語(yǔ)句中，默認(rèn)為true
updateable：可選，表示在ORM框架執(zhí)行更新操作時(shí)，該字段是否應(yīng)該出現(xiàn)在UPDATE語(yǔ)句中，默認(rèn)為true
對(duì)于一經(jīng)創(chuàng)建就不可以更改的字段，該屬性非常有用，如對(duì)于birthday字段
2-7 @Embedded注解
@Embedded
@Embedded是注釋屬性的，表示該屬性的類(lèi)是嵌入類(lèi) 注意：同時(shí)嵌入類(lèi)也必須標(biāo)注@Embeddable注解2-8 @EmbeddedId注解
@EmbeddedId
@EmbeddedId使用嵌入式主鍵類(lèi)實(shí)現(xiàn)復(fù)合主鍵 注意：嵌入式主鍵類(lèi) 必須實(shí)現(xiàn)Serializable接口 必須有默認(rèn)的public無(wú)參數(shù)的構(gòu)造方法 必須覆蓋equals和hashCode方法
代碼演示
1.編寫(xiě)StudentsPK類(lèi)
package com.myimooc.hibernateaa.entity;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Embeddable;
/**
* 學(xué)生主鍵類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@Embeddable
public class StudentsPK implements Serializable{
private static final long serialVersionUID = 1L;
/** 省份證號(hào)碼 */
@Column(length=18)
private String id;
/** 學(xué)號(hào) */
@Column(length=10)
private String sid;
public StudentsPK() {
}
@Override
public String toString() {
return "StudentsPK [id=" + id + ", sid=" + sid + "]";
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((id == null) ? 0 : id.hashCode());
result = prime * result + ((sid == null) ? 0 : sid.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
StudentsPK other = (StudentsPK) obj;
if (id == null) {
if (other.id != null)
return false;
} else if (!id.equals(other.id))
return false;
if (sid == null) {
if (other.sid != null)
return false;
} else if (!sid.equals(other.sid))
return false;
return true;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getSid() {
return sid;
}
public void setSid(String sid) {
this.sid = sid;
}
}
2.修改Students類(lèi)
package com.myimooc.hibernateaa.entity;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Embedded;
import javax.persistence.EmbeddedId;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Transient;
import org.hibernate.annotations.GenericGenerator;
/**
* 學(xué)生實(shí)體類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
@Entity
@Table(name="t_students",schema="hibernatemtm")
public class Students {
/** 學(xué)號(hào) */
/* 方式一：使用自動(dòng)生成主鍵
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private Integer sid;
*/
/* 方式二：使用手工賦值方式生成主鍵
@Id
@GeneratedValue(generator="sid")
@GenericGenerator(name="sid",strategy="assigned")//
@Column(length=8)
private String sid;
*/
/* 方式三：使用復(fù)合主鍵 */
@EmbeddedId
private StudentsPK pk;
/** 姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專(zhuān)業(yè) */
private String major;
/** 薪水 */
@Transient // 表示該屬性不會(huì)被ORM映射到表里的字段
private double salary;
/** 地址 */
@Embedded
private Address address;
@Override
public String toString() {
return "Students [pk=" + pk + ", sname=" + sname + ", gender=" + gender + ", birthday=" + birthday + ", major="
+ major + ", salary=" + salary + ", address=" + address + "]";
}
public Students() {
super();
}
public Students(StudentsPK pk, String sname, String gender, Date birthday, String major,Address address) {
super();
this.pk = pk;
this.sname = sname;
this.gender = gender;
this.birthday = birthday;
this.major = major;
this.address = address;
}
public Students(StudentsPK pk, String sname, String gender, Date birthday, String major, double salary,
Address address) {
super();
this.pk = pk;
this.sname = sname;
this.gender = gender;
this.birthday = birthday;
this.major = major;
this.salary = salary;
this.address = address;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public StudentsPK getPk() {
return pk;
}
public void setPk(StudentsPK pk) {
this.pk = pk;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
}
3.修改StudentsTest類(lèi)
package com.myimooc.hibernateaa.entity;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Before;
import org.junit.Test;
/**
* 單元測(cè)試類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
public void schemaExportTest(){
// 創(chuàng)建hibernate配置對(duì)象
Configuration config = new Configuration().configure();
// 創(chuàng)建服務(wù)注冊(cè)對(duì)象
ServiceRegistry ServiceRegistry = new ServiceRegistryBuilder()
.applySettings(config.getProperties()).buildServiceRegistry();
// 生成sessionFactory
sessionFactory = config.buildSessionFactory(ServiceRegistry);
// SchemaExport export = new SchemaExport(config);
// export.create(true, true);
}
@Test
public void addStudents(){
// 創(chuàng)建會(huì)話
Session session = sessionFactory.getCurrentSession();
// 創(chuàng)建事務(wù)
Transaction tx = session.beginTransaction();
// 創(chuàng)建一個(gè)學(xué)生對(duì)象
Address address = new Address("700005","湖北武當(dāng)山","18991167346");
// Students s = new Students("S0000002","張三豐","男",new Date(),"太極拳",address);
//
// session.save(s);
tx.commit();
}
@Test
public void addStudentsByPk(){
// 創(chuàng)建會(huì)話
Session session = sessionFactory.getCurrentSession();
// 創(chuàng)建事務(wù)
Transaction tx = session.beginTransaction();
// 創(chuàng)建一個(gè)學(xué)生對(duì)象
Address address = new Address("700005","湖北武當(dāng)山","18991167346");
// 創(chuàng)建學(xué)生主鍵對(duì)象
StudentsPK pk = new StudentsPK();
pk.setId("123456789012345678");
pk.setSid("1235241231");
Students s = new Students(pk,"張三豐","男",new Date(),"太極拳",address);
session.save(s);
tx.commit();
}
}
2-9 @Transient注解
@Transient
可選，表示該屬性并非一個(gè)到數(shù)據(jù)庫(kù)表的字段的映射，ORM框架將忽略該屬性，如果一個(gè)屬性并非數(shù)據(jù)庫(kù)表的字段映射，就務(wù)必將其表示為@Transient，否則ORM框架默認(rèn)其注解為@Basic第三章：關(guān)聯(lián)映射注解 3-1 本章簡(jiǎn)介
簡(jiǎn)介
一對(duì)一單向外鍵關(guān)聯(lián) 一對(duì)一雙向外鍵關(guān)聯(lián) 一對(duì)一單向外鍵聯(lián)合主鍵 多對(duì)一單向外鍵關(guān)聯(lián) 一對(duì)多單向外鍵關(guān)聯(lián) 一對(duì)多雙向外鍵關(guān)聯(lián) 多對(duì)多單向外鍵關(guān)聯(lián) 多對(duì)多雙向外鍵關(guān)聯(lián)3-2 實(shí)體之間的關(guān)系
實(shí)體之間的映射關(guān)系
一對(duì)一：一個(gè)公民對(duì)應(yīng)一個(gè)身份證號(hào)碼 一對(duì)多（多對(duì)一）：一個(gè)公民有多個(gè)銀行賬號(hào) 多對(duì)多：一個(gè)學(xué)生有多個(gè)老師，一個(gè)老師有多個(gè)學(xué)生3-3 一對(duì)一單向外鍵關(guān)聯(lián)（一）
一對(duì)一單向外鍵
@OneToOne(cascade=CascadeType.ALL) @JoinColumn(name=”pid”,unique=true) 注意：保存時(shí)應(yīng)該先保存外鍵對(duì)象，再保存主表對(duì)象
拷貝hibernateca項(xiàng)目，重命名為hibernatera，POM與Hibernate配置文件均相同
代碼演示
1.編寫(xiě)Students類(lèi)
package com.myimooc.hibernatera.onetoonefk;
import java.util.Date;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
/**
* 一對(duì)一單向外鍵關(guān)聯(lián)
* 學(xué)生實(shí)體類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@Entity
public class Students {
/** 學(xué)號(hào) */
@Id
@GeneratedValue
private Integer sid;
/** 身份證類(lèi) */
@OneToOne(cascade=CascadeType.ALL)
@JoinColumn(name="pid",unique=true)
private IdCard card;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專(zhuān)業(yè) */
private String major;
@Override
public String toString() {
return "Students [sid=" + sid + ", sname=" + ", gender=" + gender + ", birthday=" + birthday
+ ", major=" + major + "]";
}
public Students() {
}
public Students(IdCard card, String gender, Date birthday, String major) {
super();
this.card = card;
this.gender = gender;
this.birthday = birthday;
this.major = major;
}
public Students(IdCard card,Integer sid, String gender, Date birthday, String major) {
this.card = card;
this.sid = sid;
this.gender = gender;
this.birthday = birthday;
this.major = major;
}
public IdCard getCard() {
return card;
}
public void setCard(IdCard card) {
this.card = card;
}
public Integer getSid() {
return sid;
}
public void setSid(Integer sid) {
this.sid = sid;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
}
2.編寫(xiě)IdCard類(lèi)
package com.myimooc.hibernatera.onetoonefk;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import org.hibernate.annotations.GenericGenerator;
/**
* 一對(duì)一單向外鍵關(guān)聯(lián)
* 身份證實(shí)體類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@Entity
public class IdCard {
@Id
@GeneratedValue(generator = "pid")
@GenericGenerator(name="pid",strategy="assigned")
@Column(length=18)
/** 身份證號(hào)碼 */
private String pid;
/** 學(xué)生的姓名 */
private String sname;
public IdCard() {
}
public IdCard(String pid, String sname) {
this.pid = pid;
this.sname = sname;
}
public String getPid() {
return pid;
}
public void setPid(String pid) {
this.pid = pid;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
}
3.修改Hibernate配置文件
org.hibernate.dialect.MySQLDialect com.mysql.jdbc.Driver root root true update thread
4.編寫(xiě)StudentsTest類(lèi)
package com.myimooc.hibernatera.onetoonefk;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Before;
import org.junit.Test;
/**
* 一對(duì)一雙單外鍵關(guān)聯(lián)
* 單元測(cè)試類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
public void schemaExportTest(){
// 創(chuàng)建hibernate配置對(duì)象
Configuration config = new Configuration().configure();
// 創(chuàng)建服務(wù)注冊(cè)對(duì)象
ServiceRegistry ServiceRegistry = new ServiceRegistryBuilder()
.applySettings(config.getProperties()).buildServiceRegistry();
// 生成sessionFactory
sessionFactory = config.buildSessionFactory(ServiceRegistry);
// SchemaExport export = new SchemaExport(config);
//
// export.create(true, true);
}
}
3-4 一對(duì)一單向外鍵關(guān)聯(lián)（二）
代碼演示
1.修改StudentsTest類(lèi)
package com.myimooc.hibernatera.onetoonefk;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Before;
import org.junit.Test;
/**
* 一對(duì)一雙單外鍵關(guān)聯(lián)
* 單元測(cè)試類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
public void schemaExportTest(){
// 創(chuàng)建hibernate配置對(duì)象
Configuration config = new Configuration().configure();
// 創(chuàng)建服務(wù)注冊(cè)對(duì)象
ServiceRegistry ServiceRegistry = new ServiceRegistryBuilder()
.applySettings(config.getProperties()).buildServiceRegistry();
// 生成sessionFactory
sessionFactory = config.buildSessionFactory(ServiceRegistry);
// SchemaExport export = new SchemaExport(config);
//
// export.create(true, true);
}
/**
* 一對(duì)一單向外鍵關(guān)聯(lián)保存測(cè)試
*/
@Test
public void addStudents(){
Session session = sessionFactory.getCurrentSession();
// 生成一個(gè)身份證對(duì)象
IdCard card = new IdCard("123456789012345678","張無(wú)忌");
Transaction tx = session.beginTransaction();
// 生成學(xué)生對(duì)象
Students s = new Students(card, "男", new Date(), "太極拳");
// 先保存身份證類(lèi)的對(duì)象
session.save(card);
session.save(s);
tx.commit();
}
}
3-5 一對(duì)一雙向外鍵關(guān)聯(lián)
一對(duì)一雙向外鍵
主控方的配置同一對(duì)一單向外鍵關(guān)聯(lián)相同 @OneToOne(mappedBy=”card”)//被控方 雙向關(guān)聯(lián)，必須設(shè)置mappedBy屬性。因?yàn)殡p向關(guān)聯(lián)只能交給一方去控制 不可能在雙方都設(shè)置外鍵保存關(guān)聯(lián)關(guān)系，否則雙方都無(wú)法保存
代碼演示
1.編寫(xiě)Students類(lèi)
package com.myimooc.hibernatera.onetoonebfk;
import java.util.Date;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
/**
* 一對(duì)一雙向外鍵關(guān)聯(lián)
* 學(xué)生實(shí)體類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@Entity
public class Students {
/** 學(xué)號(hào) */
@Id
@GeneratedValue
private Integer sid;
/** 身份證類(lèi) */
@OneToOne(cascade=CascadeType.ALL)
@JoinColumn(name="pid",unique=true)
private IdCard card;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專(zhuān)業(yè) */
private String major;
@Override
public String toString() {
return "Students [sid=" + sid + ", sname=" + ", gender=" + gender + ", birthday=" + birthday
+ ", major=" + major + "]";
}
public Students() {
}
public Students(IdCard card, String gender, Date birthday, String major) {
super();
this.card = card;
this.gender = gender;
this.birthday = birthday;
this.major = major;
}
public Students(IdCard card,Integer sid, String gender, Date birthday, String major) {
this.card = card;
this.sid = sid;
this.gender = gender;
this.birthday = birthday;
this.major = major;
}
public IdCard getCard() {
return card;
}
public void setCard(IdCard card) {
this.card = card;
}
public Integer getSid() {
return sid;
}
public void setSid(Integer sid) {
this.sid = sid;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
}
2.編寫(xiě)IdCard類(lèi)
package com.myimooc.hibernatera.onetoonebfk;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import org.hibernate.annotations.GenericGenerator;
/**
* 一對(duì)一雙向外鍵關(guān)聯(lián)
* 身份證實(shí)體類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
@Entity
public class IdCard {
@Id
@GeneratedValue(generator = "pid")
@GenericGenerator(name="pid",strategy="assigned")
@Column(length=18)
/** 身份證號(hào)碼 */
private String pid;
/** 學(xué)生的姓名 */
private String sname;
/** 學(xué)生的引用 */
@OneToOne(mappedBy="card")
private Students stu;
public Students getStu() {
return stu;
}
public void setStu(Students stu) {
this.stu = stu;
}
public IdCard() {
}
public IdCard(String pid, String sname) {
this.pid = pid;
this.sname = sname;
}
public String getPid() {
return pid;
}
public void setPid(String pid) {
this.pid = pid;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
}
3.修改hibernate配置文件
org.hibernate.dialect.MySQLDialect com.mysql.jdbc.Driver root root true update thread
4.編寫(xiě)StudentsTest類(lèi)
package com.myimooc.hibernatera.onetoonebfk;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Before;
import org.junit.Test;
/**
* 一對(duì)一雙向外鍵關(guān)聯(lián)
* 單元測(cè)試類(lèi)
* @author ZhangCheng on 2017-07-12
*
*/
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
//@Test
public void schemaExportTest(){
// 創(chuàng)建hibernate配置對(duì)象
Configuration config = new Configuration().configure();
// 創(chuàng)建服務(wù)注冊(cè)對(duì)象
ServiceRegistry ServiceRegistry = new ServiceRegistryBuilder()
.applySettings(config.getProperties()).buildServiceRegistry();
// 生成sessionFactory
sessionFactory = config.buildSessionFactory(ServiceRegistry);
SchemaExport export = new SchemaExport(config);
export.create(true, true);
}
/**
* 一對(duì)一雙向外鍵關(guān)聯(lián)保存測(cè)試
*/
@Test
public void addStudents(){
Session session = sessionFactory.getCurrentSession();
// 生成一個(gè)身份證對(duì)象
IdCard card = new IdCard("123456789012345678","張無(wú)忌");
Transaction tx = session.beginTransaction();
// 生成學(xué)生對(duì)象
Students s = new Students(card, "男", new Date(), "太極拳");
// 先保存身份證類(lèi)的對(duì)象
session.save(card);
session.save(s);
tx.commit();
}
}
3-6 一對(duì)一單向外鍵聯(lián)合主鍵
一對(duì)一雙向外鍵聯(lián)合主鍵
創(chuàng)建主鍵類(lèi) 主鍵類(lèi)必須實(shí)現(xiàn)serializable接口，重寫(xiě)hashCode()和equals()方法 主鍵類(lèi)：@Embeddable 實(shí)體類(lèi)：@EmbeddedId3-7 多對(duì)一單向外鍵關(guān)聯(lián)（一）
多對(duì)一單向外鍵
多方持有一方的引用，比如：多個(gè)學(xué)生對(duì)應(yīng)一個(gè)班級(jí)（多對(duì)一）
在多方添加以下注解
@ManyToOne(cascade={CascadeType.ALL},fetch=FetchType.EAGER)
@JoinColumn(name=”cid”,referencedColumnName=”CID”)
代碼演示
1.編寫(xiě)Students類(lèi)
package com.myimooc.hibernatera.manytoonefk;
import java.util.Date;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
/**
* 多對(duì)一單向外鍵關(guān)聯(lián)
* 學(xué)生實(shí)體類(lèi)（多方）
* @author ZhangCheng on 2017-07-13
*
*/
@Entity
public class Students {
/** 學(xué)號(hào) */
@Id
@GeneratedValue
private Integer sid;
/** 學(xué)生姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專(zhuān)業(yè) */
private String major;
// 多方持有一方的引用
@ManyToOne(cascade={CascadeType.ALL},fetch=FetchType.EAGER)// 配置級(jí)聯(lián)關(guān)系和抓取策略
@JoinColumn(name="cid",referencedColumnName="CID") // 指定外鍵
private ClassRoom classRoom;
@Override
public String toString() {
return "Students [sid=" + sid + ", sname=" + ", gender=" + gender + ", birthday=" + birthday
+ ", major=" + major + "]";
}
public Students() {
}
public Students(String sname, String gender, Date birthday, String major) {
super();
this.sname = sname;
this.gender = gender;
this.birthday = birthday;
this.major = major;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public ClassRoom getClassRoom() {
return classRoom;
}
public void setClassRoom(ClassRoom classRoom) {
this.classRoom = classRoom;
}
public Integer getSid() {
return sid;
}
public void setSid(Integer sid) {
this.sid = sid;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
}
2.編寫(xiě)ClassRoom類(lèi)
package com.myimooc.hibernatera.manytoonefk;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import org.hibernate.annotations.GenericGenerator;
/**
* 多對(duì)一單向外鍵關(guān)聯(lián)
* 班級(jí)實(shí)體類(lèi)（一方）
* @author ZhangCheng on 2017-07-13
*
*/
@Entity
public class ClassRoom {
/** 班級(jí)編號(hào) */
@Id
@GeneratedValue(generator="cid")
@GenericGenerator(name="cid",strategy="assigned")
@Column(length=4)
private String cid;
/** 班級(jí)名字 */
private String cname;
public ClassRoom() {
}
public ClassRoom(String cid, String cname) {
this.cid = cid;
this.cname = cname;
}
public String getCid() {
return cid;
}
public void setCid(String cid) {
this.cid = cid;
}
public String getCname() {
return cname;
}
public void setCname(String cname) {
this.cname = cname;
}
@Override
public String toString() {
return "ClassRoom [cid=" + cid + ", cname=" + cname + "]";
}
}
3.修改hibernate配置文件
org.hibernate.dialect.MySQLDialect com.mysql.jdbc.Driver root root true update thread
4.編寫(xiě)StudentsTest類(lèi)
package com.myimooc.hibernatera.manytoonefk;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Before;
import org.junit.Test;
/**
* 多對(duì)一單向外鍵關(guān)聯(lián)
* 單元測(cè)試類(lèi)
* @author ZhangCheng on 2017-07-13
*
*/
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
//@Test
public void schemaExportTest(){
// 創(chuàng)建hibernate配置對(duì)象
Configuration config = new Configuration().configure();
// 創(chuàng)建服務(wù)注冊(cè)對(duì)象
ServiceRegistry ServiceRegistry = new ServiceRegistryBuilder()
.applySettings(config.getProperties()).buildServiceRegistry();
// 生成sessionFactory
sessionFactory = config.buildSessionFactory(ServiceRegistry);
SchemaExport export = new SchemaExport(config);
export.create(true, true);
}
}
3-8 多對(duì)一單向外鍵關(guān)聯(lián)（二）
代碼演示
1.修改StudentsTest類(lèi)
package com.myimooc.hibernatera.manytoonefk;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Before;
import org.junit.Test;
/**
* 多對(duì)一單向外鍵關(guān)聯(lián)
* 單元測(cè)試類(lèi)
* @author ZhangCheng on 2017-07-13
*
*/
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
//@Test
public void schemaExportTest(){
// 創(chuàng)建hibernate配置對(duì)象
Configuration config = new Configuration().configure();
// 創(chuàng)建服務(wù)注冊(cè)對(duì)象
ServiceRegistry ServiceRegistry = new ServiceRegistryBuilder()
.applySettings(config.getProperties()).buildServiceRegistry();
// 生成sessionFactory
sessionFactory = config.buildSessionFactory(ServiceRegistry);
SchemaExport export = new SchemaExport(config);
export.create(true, true);
}
@Test
public void addStudents(){
Session session = sessionFactory.getCurrentSession();
Transaction tx = session.beginTransaction();
// 創(chuàng)建班級(jí)對(duì)象
ClassRoom c1 = new ClassRoom("C001","軟件工程");
ClassRoom c2 = new ClassRoom("C002","網(wǎng)絡(luò)工程");
// 創(chuàng)建學(xué)生對(duì)象
Students s1 = new Students("張三","男", new Date(), "計(jì)算機(jī)");
Students s2 = new Students("李四","男", new Date(), "計(jì)算機(jī)");
Students s3 = new Students("王五","女", new Date(), "計(jì)算機(jī)");
Students s4 = new Students("趙六","女", new Date(), "計(jì)算機(jī)");
s1.setClassRoom(c1);
s2.setClassRoom(c1);
s3.setClassRoom(c2);
s4.setClassRoom(c2);
// 先保存班級(jí)
session.save(c1);
session.save(c2);
session.save(s1);
session.save(s2);
session.save(s3);
session.save(s4);
tx.commit();
}
}
3-9 一對(duì)多單向外鍵關(guān)聯(lián)
一對(duì)多單向外鍵
一方持有多方的集合，一個(gè)班級(jí)有多個(gè)學(xué)生（一對(duì)多）
在一方添加以下注解
@OneToMany(cascade={CascadeType.ALL},fetch=FetchType.LAZY)
@JoinColumn(name=”cid”)
抓取策略總結(jié)
多對(duì)一時(shí)候 多方設(shè)置EAGER：表示積極加載 一方設(shè)置LAZY：表示懶加載
代碼演示
1.編寫(xiě)Students類(lèi)
package com.myimooc.hibernatera.onetomanyfk;
import java.util.Date;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
/**
* 一對(duì)多單向外鍵關(guān)聯(lián)
* 學(xué)生實(shí)體類(lèi)（多方）
* @author ZhangCheng on 2017-07-13
*
*/
@Entity
public class Students {
/** 學(xué)號(hào) */
@Id
@GeneratedValue
private Integer sid;
/** 學(xué)生姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專(zhuān)業(yè) */
private String major;
@Override
public String toString() {
return "Students [sid=" + sid + ", sname=" + ", gender=" + gender + ", birthday=" + birthday
+ ", major=" + major + "]";
}
public Students() {
}
public Students(String sname, String gender, Date birthday, String major) {
super();
this.sname = sname;
this.gender = gender;
this.birthday = birthday;
this.major = major;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public Integer getSid() {
return sid;
}
public void setSid(Integer sid) {
this.sid = sid;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
}
2.編寫(xiě)ClassRoom類(lèi)
package com.myimooc.hibernatera.onetomanyfk;
import java.util.Set;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;
import org.hibernate.annotations.GenericGenerator;
/**
* 一對(duì)多單向外鍵關(guān)聯(lián)
* 班級(jí)實(shí)體類(lèi)（一方）
* @author ZhangCheng on 2017-07-13
*
*/
@Entity
public class ClassRoom {
/** 班級(jí)編號(hào) */
@Id
@GeneratedValue(generator="cid")
@GenericGenerator(name="cid",strategy="assigned")
@Column(length=4)
private String cid;
/** 班級(jí)名字 */
private String cname;
// 一方持有多方的集合
@OneToMany(cascade={CascadeType.ALL},fetch=FetchType.LAZY)
@JoinColumn(name="cid")
private Set stus;
public ClassRoom() {
}
public ClassRoom(String cid, String cname) {
this.cid = cid;
this.cname = cname;
}
public Set getStus() {
return stus;
}
public void setStus(Set stus) {
this.stus = stus;
}
public String getCid() {
return cid;
}
public void setCid(String cid) {
this.cid = cid;
}
public String getCname() {
return cname;
}
public void setCname(String cname) {
this.cname = cname;
}
@Override
public String toString() {
return "ClassRoom [cid=" + cid + ", cname=" + cname + "]";
}
}
3.修改hibernate配置文件
同上
4.編寫(xiě)StudentsTest類(lèi)
package com.myimooc.hibernatera.onetomanyfk;
import java.util.Date;
import java.util.HashSet;
import java.util.Set;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Before;
import org.junit.Test;
/**
* 一對(duì)多單向外鍵關(guān)聯(lián)
* 單元測(cè)試類(lèi)
* @author ZhangCheng on 2017-07-13
*
*/
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
//@Test
public void schemaExportTest(){
// 創(chuàng)建hibernate配置對(duì)象
Configuration config = new Configuration().configure();
/
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