Java进阶知识08 Hibernate一对一双向外键关联（Annotation+XML实现）

1、Annotation 注解版

1.1、创建Husband类和Wife类

 1 package com.shore.model;
 2 
 3 import javax.persistence.Entity;
 4 import javax.persistence.GeneratedValue;
 5 import javax.persistence.GenerationType;
 6 import javax.persistence.Id;
 7 import javax.persistence.OneToOne;
 8 
 9 import org.hibernate.annotations.Type;
10 
11 /**
12  * @author DSHORE/2019-9-18
13  * 一对一，双向关联（注解版）
14  */
15 @Entity
16 public class Husband {//主表 类
17     private Integer id;
18     private String name;
19     private Boolean sex;
20     private Wife wife;
21 
22     @Id
23     @GeneratedValue(strategy = GenerationType.AUTO) //主键生成策略(使用test()测试时，必须加上这个，否会报错：id生成错误)
24     public Integer getId() {
25         return id;
26     }
27     public void setId(Integer id) {
28         this.id = id;
29     }
30     public String getName() {
31         return name;
32     }
33     public void setName(String name) {
34         this.name = name;
35     }
36     
37     @Type(type = "yes_no") //数据库中，会以Y/N的形式插入到sex字段中
38     public Boolean getSex() {
39         return sex;
40     }
41     public void setSex(Boolean sex) {
42         this.sex = sex;
43     }
44     
45     @OneToOne(mappedBy="husband")//映射：从表wife映射主表husband。如果不要(mappedBy="husband")，主表husband将会多一个没必要的字段wife_id（外键）
46     public Wife getWife() {
47         return wife;
48     }
49     public void setWife(Wife wife) {
50         this.wife = wife;
51     }
52 }

Wife类

 1 package com.shore.model;
 2 
 3 import javax.persistence.Entity;
 4 import javax.persistence.GeneratedValue;
 5 import javax.persistence.GenerationType;
 6 import javax.persistence.Id;
 7 import javax.persistence.JoinColumn;
 8 import javax.persistence.OneToOne;
 9 
10 import org.hibernate.annotations.Type;
11 
12 /**
13  * @author DSHORE/2019-9-18
14  * 一对一，双向关联（注解版）
15  */
16 @Entity
17 public class Wife {//从表
18     private Integer id;
19     private String name;
20     private Boolean sex;
21     private Husband husband;
22 
23     @Id
24     @GeneratedValue(strategy = GenerationType.AUTO) //主键生成策略(使用test1测试时，必须加上这个，否会报错：id生成错误)
25     public Integer getId() {
26         return id;
27     }
28     public void setId(Integer id) {
29         this.id = id;
30     }
31     public String getName() {
32         return name;
33     }
34     public void setName(String name) {
35         this.name = name;
36     }
37     
38     @Type(type = "yes_no") //数据库中，会以Y/N的形式插入到sex字段中
39     public Boolean getSex() {
40         return sex;
41     }
42     public void setSex(Boolean sex) {
43         this.sex = sex;
44     }
45     
46     @OneToOne  //默认创建的外键名称：husband_id
47     @JoinColumn(name="husbandId") //创建表时，指定该外键名：husbandId
48     public Husband getHusband() {
49         return husband;
50     }
51     public void setHusband(Husband husband) {
52         this.husband = husband;
53     }
54 }

1.2、创建hibernate.cfg.xml核心配置文件

 1 <?xml version='1.0' encoding='utf-8'?>
 2 <!DOCTYPE hibernate-configuration PUBLIC
 3         "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
 4         "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
 5 
 6 <hibernate-configuration>
 7     <session-factory>
 8         <!-- Database connection settings -->
 9         <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
10         <property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property>
11         <property name="connection.username">root</property>
12         <property name="connection.password">123456</property>
13 
14         <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
15         <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
16         <property name="show_sql">true</property>
17         <property name="hbm2ddl.auto">create</property>
18 
19         <mapping class="com.shore.model.Husband" />
20         <mapping class="com.shore.model.Wife" />
21     </session-factory>
22 </hibernate-configuration>

1.3、开始测试

 1 package com.shore.test;
 2 
 3 import org.hibernate.Session;
 4 import org.hibernate.SessionFactory;
 5 import org.hibernate.Transaction;
 6 import org.hibernate.cfg.AnnotationConfiguration;
 7 import org.junit.AfterClass;
 8 import org.junit.BeforeClass;
 9 import org.junit.Test;
10 
11 import com.shore.model.Husband;
12 import com.shore.model.Wife;
13 
14 /**
15  * @author DSHORE/2019-9-18
16  *
17  */
18 public class AnnotationTest {
19     public static SessionFactory sessionFactory = null;
20     public static Session session = null;
21     
22     @BeforeClass
23     public static void buildSessionFactory() {
24         sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
25     }
26     
27     @AfterClass
28     public static void close() {
29         session.close();
30         sessionFactory.close();
31     }
32     
33     @Test
34     public void test(){//数据库表创建完后，插入数据
35         session = sessionFactory.openSession(); //打开一个session
36         Transaction transaction = session.beginTransaction(); //开启一个事务
37         Husband husband = new Husband();
38         husband.setName("黄晓明");
39         husband.setSex(true);//男
40         session.save(husband);
41         
42         Wife wife = new Wife();
43         wife.setName("AnglaBaby");
44         wife.setSex(false);//女
45         wife.setHusband(husband);
46         session.save(wife);
47         transaction.commit(); //事务提交
48     }
49 }

测试结果图：

2、XML实现版

2.1、创建husband类和wife类

 1 package com.shore.model;
 2 
 3 /**
 4  * @author DSHORE/2019-9-18
 5  * 一对一，双向关联（xml版）
 6  */
 7 public class Husband {//主表 类
 8     private Integer id;
 9     private String name;
10     private Boolean sex;
11     private Wife wife;
12 
13     public Integer getId() {
14         return id;
15     }
16     public void setId(Integer id) {
17         this.id = id;
18     }
19     public String getName() {
20         return name;
21     }
22     public void setName(String name) {
23         this.name = name;
24     }
25     public Boolean getSex() {
26         return sex;
27     }
28     public void setSex(Boolean sex) {
29         this.sex = sex;
30     }
31     public Wife getWife() {
32         return wife;
33     }
34     public void setWife(Wife wife) {
35         this.wife = wife;
36     }
37 }

wife类

 1 package com.shore.model;
 2 
 3 /**
 4  * @author DSHORE/2019-9-18
 5  * 一对一，双向关联（xml版）
 6  */
 7 public class Wife {//从表 类
 8     private Integer id;
 9     private String name;
10     private Boolean sex;
11     private Husband husband;
12 
13     public Integer getId() {
14         return id;
15     }
16     public void setId(Integer id) {
17         this.id = id;
18     }
19     public String getName() {
20         return name;
21     }
22     public void setName(String name) {
23         this.name = name;
24     }
25     public Boolean getSex() {
26         return sex;
27     }
28     public void setSex(Boolean sex) {
29         this.sex = sex;
30     }
31     public Husband getHusband() {
32         return husband;
33     }
34     public void setHusband(Husband husband) {
35         this.husband = husband;
36     }
37 }

2.2、创建 Husband.hbm.xml 配置文件和 Wife.hbm.xml 配置文件

 1 <?xml version="1.0"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC
 3         "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4         "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 5         
 6 <hibernate-mapping package="com.shore.model">
 7     <class name="Husband" table="husband_xml">  
 8         <id name="id"> 
 9             <generator class="native"/>
10         </id>
11         <property name="name" type="java.lang.String"/>
12         <property name="sex" type="yes_no"/>
13         
14        <!-- 这里不能这么配置，否则主表husband里面会多一个没必要的外键wife_id
15         <many-to-one name="wife" column="wife_id" unique="true"/> -->
16         
17         <!-- 应该这样配置 -->
18         <one-to-one name="wife" property-ref="husband"/>
19     </class>
20 </hibernate-mapping>

Wife.hbm.xml 配置文件

 1 <?xml version="1.0"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC
 3         "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4         "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 5         
 6 <hibernate-mapping package="com.shore.model">
 7     <class name="Wife" table="wife_xml">  
 8         <id name="id"> 
 9             <generator class="native"/>
10         </id>
11         <property name="name" type="java.lang.String"/>
12         <property name="sex" type="yes_no" />
13         
14         <!-- many-to-one:多对一，但加了个unique="true"，就变成了一对一 -->
15         <many-to-one name="husband" column="husband_id" unique="true"/>
16     </class>
17 </hibernate-mapping>

2.3、创建hibernate.cfg.xml 核心配置文件

 1 <?xml version='1.0' encoding='utf-8'?>
 2 <!DOCTYPE hibernate-configuration PUBLIC
 3         "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
 4         "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
 5 
 6 <hibernate-configuration>
 7     <session-factory>
 8         <!-- Database connection settings -->
 9         <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
10         <property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property>
11         <property name="connection.username">root</property>
12         <property name="connection.password">123456</property>
13 
14         <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
15         <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
16         <property name="show_sql">true</property>
17         <property name="hbm2ddl.auto">create</property>
18 
19         <!-- <mapping class="com.shore.model.Husband" />
20         <mapping class="com.shore.model.Wife" /> -->
21         <mapping resource="com/shore/model/Husband.hbm.xml" />
22         <mapping resource="com/shore/model/Wife.hbm.xml" />
23     </session-factory>
24 </hibernate-configuration>

2.4、开始测试

 1 package com.shore.test;
 2 
 3 import org.hibernate.Session;
 4 import org.hibernate.SessionFactory;
 5 import org.hibernate.Transaction;
 6 import org.hibernate.cfg.Configuration;
 7 import org.junit.AfterClass;
 8 import org.junit.BeforeClass;
 9 import org.junit.Test;
10 
11 import com.shore.model.Husband;
12 import com.shore.model.Wife;
13 
14 /**
15  * @author DSHORE/2019-9-19
16  *
17  */
18 public class XMLTest {
19     public static SessionFactory sessionFactory = null;
20     public static Session session = null;
21     
22     @BeforeClass
23     public static void buildSessionFactory() {
24                 //用注解版的话，Configuration()方法，得改用AnnotationConfiguration()方法
25         sessionFactory = new Configuration().configure().buildSessionFactory();
26     }
27     
28     @AfterClass
29     public static void close() {
30         session.close();
31         sessionFactory.close();
32     }
33     
34     @Test
35     public void test(){//数据库表创建完后，插入数据
36         session = sessionFactory.openSession();
37         Transaction transaction = session.beginTransaction();
38         Husband husband = new Husband();
39         husband.setName("黄晓明");
40         husband.setSex(true);//男
41         session.save(husband);
42         
43         Wife wife = new Wife();
44         wife.setName("AnglaBaby");
45         wife.setSex(false);//女
46         wife.setHusband(husband);
47         session.save(wife);
48         transaction.commit();//事务提交
49     }
50 }