資訊專欄INFORMATION COLUMN
摘要：時間年月日星期二說明本文部分內容均來自慕課網。文件如下在目錄下，創建文件指定映射文件的路徑注解映射實體類可選，對應數據庫中的一個表。
時間：2017年07月11日星期二
說明：本文部分內容均來自慕課網。@慕課網：http://www.imooc.com
教學源碼：無
學習源碼：https://github.com/zccodere/s...
本章簡介
Hibernate注解簡介 JPA與Hibernate的關系 Hibernate注解分類 @Entity @Table @Embeddable schema與catalog
Hibernate注解簡介
使用注解的目的：為了簡化繁瑣的ORM映射文件（*.hbm）的配置
JPA與Hibernate的關系
什么是JPA
全稱Java Persistence API
JPA注解是JavaEE的規范和標準
JPA和Hibernate的關系：
JPA是標準接口
Hibernate是實現，但是其功能是JPA的超集
Hibernate如何實現與JPA的關系
通過hibernate-annotation
hibernate-entitymanager
hibernate-core三個組件來實現
一般在實際開發中，優先考慮使用JPA注解
這樣更有利于程序的移植和擴展
Hibernate注解的分類
類級別注解 屬性級別注解 映射關系注解
類級別注解
@Entity：表示一個實體，一個實體對應數據庫一張表 @Table：配置表的屬性 @Embeddable：表示當前類是一個嵌入類1-2 準備工作
回顧hibernate.cfg.xml
創建一個名為hibernateca的maven項目，并添加相關依賴。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：映射實體類 @Entity(name=”tableName”) name：可選，對應數據庫中的一個表。若表名與實體類名相同，則可以省略 注意：使用@Entity時必須指定實體類的主鍵屬性
代碼演示
1.編寫Students實體類
package com.myimooc.hibernateca.entity;
import java.util.Date;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
/**
* 學生實體類
* @author ZhangCheng on 2017-07-12
*
*/
//JPA注解
@Entity(name="t_students")
public class Students {
/** 學號 */
@Id
private Integer sid;
/** 姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專業 */
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StudentTest測試類
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;
/**
* 單元測試類
* @author ZhangCheng on 2017-07-12
*
*/
public class StudentsTest {
@Test
public void schemaExportTest(){
// 創建hibernate配置對象
Configuration config = new Configuration().configure();
// 創建服務注冊對象
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，只能標注在實體的class定義處，表示實體對應的數據庫表的信息 name：可選，映射表的名稱，默認表名和實體名稱一致，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，默認為Catalog(“”) schema：可選，表示模式Schema名稱，默認為Schema(“”)
schema與catalog示意圖
schema與catalog
從實現的角度來看，各種數據庫系統對Catalog和Schema的支持和實現方式千差萬別的
供應商的支持和實現
代碼演示，修改Student類如下
package com.myimooc.hibernateca.entity;
import java.util.Date;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
/**
* 學生實體類
* @author ZhangCheng on 2017-07-12
*
*/
//JPA注解
//@Entity(name="t_students")
@Entity
@Table(name="t_students",schema="hibernatemtm")
public class Students {
/** 學號 */
@Id
private Integer sid;
/** 姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專業 */
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表示一個非Entity類可以嵌入到另一個Entity類中作為屬性而存在
代碼演示
1.編寫Address類
package com.myimooc.hibernateca.entity;
import javax.persistence.Embeddable;
/**
* 地址類（嵌入類）
* @author ZhangCheng on 2017-07-12
*
*/
// 表示是一個嵌入類，這個類的對象在另一個實體類中充當屬性
@Embeddable
public class Address {
/** 郵編 */
private String postCode;
/** 地址 */
private String address;
/** 聯系電話 */
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類如下
package com.myimooc.hibernateca.entity;
import java.util.Date;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
/**
* 學生實體類
* @author ZhangCheng on 2017-07-12
*
*/
//JPA注解
//@Entity(name="t_students")
@Entity
@Table(name="t_students",schema="hibernatemtm")
public class Students {
/** 學號 */
@Id
private Integer sid;
/** 姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專業 */
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：屬性級別注解
2-1 本章簡介
Hibernate屬性級別注解
添加方式：寫在屬性字段方面 或 寫在屬性的get訪問器的上面 @Id -@SequenceGenerator @GeneratedValue @Column @Embedded @EmbeddedId -@Lob -@Version -@Basic @Transient2-2 @Id注解
@Id
@Id：必須，定義了映射到數據庫表的主鍵的屬性， 一個實體類可以有一個或者多個屬性被映射為主鍵， 可置于主鍵屬性或者get方法前 注意：如果有多個屬性定義為主鍵屬性， 該實體類必須實現serializable接口
拷貝hibernateca項目，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，用戶定義主鍵生成策略
strategy表示主鍵生成策略，取值有
GenerationType.AUTO:根據底層數據庫自動選擇（默認）
GenerationType.INDENTITY：根據數據庫的Identity字段生成
GenerationType.SEQUENCE：使用Sequence來決定主鍵的取值
GenerationType.TABLE：使用指定表來決定主鍵取值，結合@TableGenerator使用
使用示例
2-4 @GeneratedValue注解（二）代碼演示
1.修改Students類
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;
/**
* 學生實體類
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
@Entity
@Table(name="t_students",schema="hibernatemtm")
public class Students {
/** 學號 */
/* 方式一：使用自動生成主鍵
@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;
/** 專業 */
private String major;
/** 薪水 */
@Transient // 表示該屬性不會被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
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;
/**
* 單元測試類
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
public void schemaExportTest(){
// 創建hibernate配置對象
Configuration config = new Configuration().configure();
// 創建服務注冊對象
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(){
// 創建會話
Session session = sessionFactory.getCurrentSession();
// 創建事務
Transaction tx = session.beginTransaction();
// 創建一個學生對象
Address address = new Address("700005","湖北武當山","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(){
// 創建會話
Session session = sessionFactory.getCurrentSession();
// 創建事務
Transaction tx = session.beginTransaction();
// 創建一個學生對象
Address address = new Address("700005","湖北武當山","18991167346");
// 創建學生主鍵對象
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，使用該注解來覆蓋默認值 @Column描述了數據庫表中該字段的詳細定義 這對于根據JPA注解生成數據庫表結構的工具非常有作用
常用屬性
name：可選，表示數據庫表中該字段的名稱，默認與屬性名稱一致
nullable：可選，表示該字段是否允許為null，默認為true
unique：可選，表示該字段是否是唯一標識，默認為false
length：可選，表示該字段的大小，僅對String類型的字段有效，默認為255
（如果是主鍵不能使用默認值）
insertable：可選，表示在ORM框架執行插入操作時，該字段是否應出現INSERT語句中，默認為true
updateable：可選，表示在ORM框架執行更新操作時，該字段是否應該出現在UPDATE語句中，默認為true
對于一經創建就不可以更改的字段，該屬性非常有用，如對于birthday字段
2-7 @Embedded注解
@Embedded
@Embedded是注釋屬性的，表示該屬性的類是嵌入類 注意：同時嵌入類也必須標注@Embeddable注解2-8 @EmbeddedId注解
@EmbeddedId
@EmbeddedId使用嵌入式主鍵類實現復合主鍵 注意：嵌入式主鍵類 必須實現Serializable接口 必須有默認的public無參數的構造方法 必須覆蓋equals和hashCode方法
代碼演示
1.編寫StudentsPK類
package com.myimooc.hibernateaa.entity;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Embeddable;
/**
* 學生主鍵類
* @author ZhangCheng on 2017-07-12
*
*/
@Embeddable
public class StudentsPK implements Serializable{
private static final long serialVersionUID = 1L;
/** 省份證號碼 */
@Column(length=18)
private String id;
/** 學號 */
@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
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;
/**
* 學生實體類
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
@Entity
@Table(name="t_students",schema="hibernatemtm")
public class Students {
/** 學號 */
/* 方式一：使用自動生成主鍵
@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;
/** 專業 */
private String major;
/** 薪水 */
@Transient // 表示該屬性不會被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
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;
/**
* 單元測試類
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
public void schemaExportTest(){
// 創建hibernate配置對象
Configuration config = new Configuration().configure();
// 創建服務注冊對象
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(){
// 創建會話
Session session = sessionFactory.getCurrentSession();
// 創建事務
Transaction tx = session.beginTransaction();
// 創建一個學生對象
Address address = new Address("700005","湖北武當山","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(){
// 創建會話
Session session = sessionFactory.getCurrentSession();
// 創建事務
Transaction tx = session.beginTransaction();
// 創建一個學生對象
Address address = new Address("700005","湖北武當山","18991167346");
// 創建學生主鍵對象
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到數據庫表的字段的映射，ORM框架將忽略該屬性，如果一個屬性并非數據庫表的字段映射，就務必將其表示為@Transient，否則ORM框架默認其注解為@Basic第三章：關聯映射注解 3-1 本章簡介
簡介
一對一單向外鍵關聯 一對一雙向外鍵關聯 一對一單向外鍵聯合主鍵 多對一單向外鍵關聯 一對多單向外鍵關聯 一對多雙向外鍵關聯 多對多單向外鍵關聯 多對多雙向外鍵關聯3-2 實體之間的關系
實體之間的映射關系
一對一：一個公民對應一個身份證號碼 一對多（多對一）：一個公民有多個銀行賬號 多對多：一個學生有多個老師，一個老師有多個學生3-3 一對一單向外鍵關聯（一）
一對一單向外鍵
@OneToOne(cascade=CascadeType.ALL) @JoinColumn(name=”pid”,unique=true) 注意：保存時應該先保存外鍵對象，再保存主表對象
拷貝hibernateca項目，重命名為hibernatera，POM與Hibernate配置文件均相同
代碼演示
1.編寫Students類
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;
/**
* 一對一單向外鍵關聯
* 學生實體類
* @author ZhangCheng on 2017-07-12
*
*/
@Entity
public class Students {
/** 學號 */
@Id
@GeneratedValue
private Integer sid;
/** 身份證類 */
@OneToOne(cascade=CascadeType.ALL)
@JoinColumn(name="pid",unique=true)
private IdCard card;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專業 */
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IdCard類
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;
/**
* 一對一單向外鍵關聯
* 身份證實體類
* @author ZhangCheng on 2017-07-12
*
*/
@Entity
public class IdCard {
@Id
@GeneratedValue(generator = "pid")
@GenericGenerator(name="pid",strategy="assigned")
@Column(length=18)
/** 身份證號碼 */
private String pid;
/** 學生的姓名 */
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StudentsTest類
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;
/**
* 一對一雙單外鍵關聯
* 單元測試類
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
public void schemaExportTest(){
// 創建hibernate配置對象
Configuration config = new Configuration().configure();
// 創建服務注冊對象
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 一對一單向外鍵關聯（二）
代碼演示
1.修改StudentsTest類
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;
/**
* 一對一雙單外鍵關聯
* 單元測試類
* @author ZhangCheng on 2017-07-12
*
*/
@SuppressWarnings("unused")
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
public void schemaExportTest(){
// 創建hibernate配置對象
Configuration config = new Configuration().configure();
// 創建服務注冊對象
ServiceRegistry ServiceRegistry = new ServiceRegistryBuilder()
.applySettings(config.getProperties()).buildServiceRegistry();
// 生成sessionFactory
sessionFactory = config.buildSessionFactory(ServiceRegistry);
// SchemaExport export = new SchemaExport(config);
//
// export.create(true, true);
}
/**
* 一對一單向外鍵關聯保存測試
*/
@Test
public void addStudents(){
Session session = sessionFactory.getCurrentSession();
// 生成一個身份證對象
IdCard card = new IdCard("123456789012345678","張無忌");
Transaction tx = session.beginTransaction();
// 生成學生對象
Students s = new Students(card, "男", new Date(), "太極拳");
// 先保存身份證類的對象
session.save(card);
session.save(s);
tx.commit();
}
}
3-5 一對一雙向外鍵關聯
一對一雙向外鍵
主控方的配置同一對一單向外鍵關聯相同 @OneToOne(mappedBy=”card”)//被控方 雙向關聯，必須設置mappedBy屬性。因為雙向關聯只能交給一方去控制 不可能在雙方都設置外鍵保存關聯關系，否則雙方都無法保存
代碼演示
1.編寫Students類
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;
/**
* 一對一雙向外鍵關聯
* 學生實體類
* @author ZhangCheng on 2017-07-12
*
*/
@Entity
public class Students {
/** 學號 */
@Id
@GeneratedValue
private Integer sid;
/** 身份證類 */
@OneToOne(cascade=CascadeType.ALL)
@JoinColumn(name="pid",unique=true)
private IdCard card;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專業 */
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IdCard類
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;
/**
* 一對一雙向外鍵關聯
* 身份證實體類
* @author ZhangCheng on 2017-07-12
*
*/
@Entity
public class IdCard {
@Id
@GeneratedValue(generator = "pid")
@GenericGenerator(name="pid",strategy="assigned")
@Column(length=18)
/** 身份證號碼 */
private String pid;
/** 學生的姓名 */
private String sname;
/** 學生的引用 */
@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StudentsTest類
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;
/**
* 一對一雙向外鍵關聯
* 單元測試類
* @author ZhangCheng on 2017-07-12
*
*/
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
//@Test
public void schemaExportTest(){
// 創建hibernate配置對象
Configuration config = new Configuration().configure();
// 創建服務注冊對象
ServiceRegistry ServiceRegistry = new ServiceRegistryBuilder()
.applySettings(config.getProperties()).buildServiceRegistry();
// 生成sessionFactory
sessionFactory = config.buildSessionFactory(ServiceRegistry);
SchemaExport export = new SchemaExport(config);
export.create(true, true);
}
/**
* 一對一雙向外鍵關聯保存測試
*/
@Test
public void addStudents(){
Session session = sessionFactory.getCurrentSession();
// 生成一個身份證對象
IdCard card = new IdCard("123456789012345678","張無忌");
Transaction tx = session.beginTransaction();
// 生成學生對象
Students s = new Students(card, "男", new Date(), "太極拳");
// 先保存身份證類的對象
session.save(card);
session.save(s);
tx.commit();
}
}
3-6 一對一單向外鍵聯合主鍵
一對一雙向外鍵聯合主鍵
創建主鍵類 主鍵類必須實現serializable接口，重寫hashCode()和equals()方法 主鍵類：@Embeddable 實體類：@EmbeddedId3-7 多對一單向外鍵關聯（一）
多對一單向外鍵
多方持有一方的引用，比如：多個學生對應一個班級（多對一）
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Students類
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;
/**
* 多對一單向外鍵關聯
* 學生實體類（多方）
* @author ZhangCheng on 2017-07-13
*
*/
@Entity
public class Students {
/** 學號 */
@Id
@GeneratedValue
private Integer sid;
/** 學生姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專業 */
private String major;
// 多方持有一方的引用
@ManyToOne(cascade={CascadeType.ALL},fetch=FetchType.EAGER)// 配置級聯關系和抓取策略
@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ClassRoom類
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;
/**
* 多對一單向外鍵關聯
* 班級實體類（一方）
* @author ZhangCheng on 2017-07-13
*
*/
@Entity
public class ClassRoom {
/** 班級編號 */
@Id
@GeneratedValue(generator="cid")
@GenericGenerator(name="cid",strategy="assigned")
@Column(length=4)
private String cid;
/** 班級名字 */
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StudentsTest類
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;
/**
* 多對一單向外鍵關聯
* 單元測試類
* @author ZhangCheng on 2017-07-13
*
*/
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
//@Test
public void schemaExportTest(){
// 創建hibernate配置對象
Configuration config = new Configuration().configure();
// 創建服務注冊對象
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 多對一單向外鍵關聯（二）
代碼演示
1.修改StudentsTest類
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;
/**
* 多對一單向外鍵關聯
* 單元測試類
* @author ZhangCheng on 2017-07-13
*
*/
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
//@Test
public void schemaExportTest(){
// 創建hibernate配置對象
Configuration config = new Configuration().configure();
// 創建服務注冊對象
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();
// 創建班級對象
ClassRoom c1 = new ClassRoom("C001","軟件工程");
ClassRoom c2 = new ClassRoom("C002","網絡工程");
// 創建學生對象
Students s1 = new Students("張三","男", new Date(), "計算機");
Students s2 = new Students("李四","男", new Date(), "計算機");
Students s3 = new Students("王五","女", new Date(), "計算機");
Students s4 = new Students("趙六","女", new Date(), "計算機");
s1.setClassRoom(c1);
s2.setClassRoom(c1);
s3.setClassRoom(c2);
s4.setClassRoom(c2);
// 先保存班級
session.save(c1);
session.save(c2);
session.save(s1);
session.save(s2);
session.save(s3);
session.save(s4);
tx.commit();
}
}
3-9 一對多單向外鍵關聯
一對多單向外鍵
一方持有多方的集合，一個班級有多個學生（一對多）
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
多對一時候 多方設置EAGER：表示積極加載 一方設置LAZY：表示懶加載
代碼演示
1.編寫Students類
package com.myimooc.hibernatera.onetomanyfk;
import java.util.Date;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
/**
* 一對多單向外鍵關聯
* 學生實體類（多方）
* @author ZhangCheng on 2017-07-13
*
*/
@Entity
public class Students {
/** 學號 */
@Id
@GeneratedValue
private Integer sid;
/** 學生姓名 */
private String sname;
/** 性別 */
private String gender;
/** 出生日期 */
private Date birthday;
/** 專業 */
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ClassRoom類
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;
/**
* 一對多單向外鍵關聯
* 班級實體類（一方）
* @author ZhangCheng on 2017-07-13
*
*/
@Entity
public class ClassRoom {
/** 班級編號 */
@Id
@GeneratedValue(generator="cid")
@GenericGenerator(name="cid",strategy="assigned")
@Column(length=4)
private String cid;
/** 班級名字 */
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StudentsTest類
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;
/**
* 一對多單向外鍵關聯
* 單元測試類
* @author ZhangCheng on 2017-07-13
*
*/
public class StudentsTest {
private SessionFactory sessionFactory = null;
@Before
//@Test
public void schemaExportTest(){
// 創建hibernate配置對象
Configuration config = new Configuration().configure();
/
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