Java进阶知识09 Hibernate一对多单向关联（Annotation+XML实现）

1、Annotation 注解版

1.1、在一的一方加Set

1.2、创建Customer类和Order类

 package com.shore.model;

 import java.util.HashSet;
 import java.util.Set;

 import javax.persistence.Entity;
 import javax.persistence.Id;
 import javax.persistence.JoinColumn;
 import javax.persistence.OneToMany;
 import javax.persistence.Table;

 /**
  * @author DSHORE/2019-9-19
  * 一对多，单向关联（注解版）
  */
 @Entity
 @Table(name="anno_customer")
 public class Customer {//顾客  （“一”的一方），在“一”的一方加Set
     private Integer id;
     private String name;
     private Integer age;
     private Set<Order> orders = new HashSet<Order>();  //在“一”的一方加Set
     /**
      * List 有序，可重复，可以用index取值（get(index)）
      * Set  无序，不可重复
      */

     @Id
     public Integer getId() {
         return id;
     }
     public void setId(Integer id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public Integer getAge() {
         return age;
     }
     public void setAge(Integer age) {
         this.age = age;
     }

     @OneToMany  //一对多
     @JoinColumn(name="customerId")
     public Set<Order> getOrders() {//在“一”的一方加Set
         return orders;
     }
     public void setOrders(Set<Order> orders) {
         this.orders = orders;
     }
 }

Order类

 package com.shore.model;

 import javax.persistence.Entity;
 import javax.persistence.Id;
 import javax.persistence.Table;

 /**
  * @author DSHORE/2019-9-19
  *  一对多，单向关联（注解版）
  */
 @Entity
 @Table(name="anno_order") //Order是MySQL数据库关键字。需重新定义表名
 public class Order {//订单  （“多”的一方）
     private Integer id;
     private String number;
     private Float sum;

     @Id
     public Integer getId() {
         return id;
     }
     public void setId(Integer id) {
         this.id = id;
     }
     public String getNumber() {
         return number;
     }
     public void setNumber(String number) {
         this.number = number;
     }
     public Float getSum() {
         return sum;
     }
     public void setSum(Float sum) {
         this.sum = sum;
     }
 }

1.3、创建hibernate.cfg.xml核心配置文件

 <?xml version='1.0' encoding='utf-8'?>
 <!DOCTYPE hibernate-configuration PUBLIC
         "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
         "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

 <hibernate-configuration>
     <session-factory>
         <!-- Database connection settings -->
         <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
         <property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property>
         <property name="connection.username">root</property>
         <property name="connection.password">123456</property>

         <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
         <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
         <property name="show_sql">true</property>
         <property name="hbm2ddl.auto">create</property>

         <mapping class="com.shore.model.Customer" />
         <mapping class="com.shore.model.Order" />
         <!-- <mapping resource="com/shore/model/Customer.hbm.xml" />
         <mapping resource="com/shore/model/Order.hbm.xml" /> -->
     </session-factory>
 </hibernate-configuration>

1.4、开始测试

 package com.shore.test;

 import org.hibernate.cfg.AnnotationConfiguration;
 import org.hibernate.tool.hbm2ddl.SchemaExport;
 import org.junit.Test;

 /**
  * @author DSHORE/2019-9-19
  *
  */
 public class AnnotationTest {
     @Test
     public void test() {//简单测试，只创建表，不插入数据
                     //注解版，用AnnotationConfiguration()方法
         new SchemaExport(new AnnotationConfiguration().configure()).create(
                 false, true);
     }
 }

测试结果图：

　　　　

2、XML版 的实现

2.1、创建Customer类和Order类

 package com.shore.model;

 import java.util.HashSet;
 import java.util.Set;

 /**
  * @author DSHORE/2019-9-19
  * 一对多，单向关联（xml版）
  */
 public class Customer {//顾客  （“一”的一方），在一的一方加Set
     private Integer id;
     private String name;
     private Integer age;
     private Set<Order> orders = new HashSet<Order>(); //在“一”的一方加Set

     public Integer getId() {
         return id;
     }
     public void setId(Integer id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public Integer getAge() {
         return age;
     }
     public void setAge(Integer age) {
         this.age = age;
     }
     public Set<Order> getOrders() {
         return orders;
     }
     public void setOrders(Set<Order> orders) {
         this.orders = orders;
     }
 }

Order类

 package com.shore.model;

 /**
  * @author DSHORE/2019-9-19
  * 一对多，单向关联（xml版）
  */
 public class Order {//订单  （“多”的一方）
     private Integer id;
     private String number;
     private Float sum;

     public Integer getId() {
         return id;
     }
     public void setId(Integer id) {
         this.id = id;
     }
     public String getNumber() {
         return number;
     }
     public void setNumber(String number) {
         this.number = number;
     }
     public Float getSum() {
         return sum;
     }
     public void setSum(Float sum) {
         this.sum = sum;
     }
 }

2.2、创建 Customer.hbm.xml 配置文件和 Order.hbm.xml 配置文件

 <?xml version="1.0"?>
 <!DOCTYPE hibernate-mapping PUBLIC
         "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
         "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

 <hibernate-mapping package="com.shore.model">
     <class name="Customer" table="customer_xml">
        <id name="id">
             <generator class="native"/>
         </id>
         <property name="name" type="java.lang.String"/>
         <property name="age" type="java.lang.Integer"/>

         <!-- 一对多，在“一”的一方的配置文件中用set标签 -->
         <set name="orders">
             <key column="customerId"></key>
             <one-to-many class="com.shore.model.Order"/>
         </set>
     </class>
 </hibernate-mapping>

Order.hbm.xml 配置文件

 <?xml version="1.0"?>
 <!DOCTYPE hibernate-mapping PUBLIC
         "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
         "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

 <hibernate-mapping package="com.shore.model">
     <class name="Order" table="order_xml">
         <id name="id">
             <generator class="native"/>
         </id>
         <property name="number" type="java.lang.String"/>
         <property name="sum" type="java.lang.Float"/>
     </class>
 </hibernate-mapping>

2.3、创建hibernate.cfg.xml 核心配置文件

 <?xml version='1.0' encoding='utf-8'?>
 <!DOCTYPE hibernate-configuration PUBLIC
         "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
         "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

 <hibernate-configuration>
     <session-factory>
         <!-- Database connection settings -->
         <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
         <property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property>
         <property name="connection.username">root</property>
         <property name="connection.password">123456</property>

         <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
         <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
         <property name="show_sql">true</property>
         <property name="hbm2ddl.auto">create</property>

         <!-- <mapping class="com.shore.model.Customer" />
         <mapping class="com.shore.model.Order" /> -->
         <mapping resource="com/shore/model/Customer.hbm.xml" />
         <mapping resource="com/shore/model/Order.hbm.xml" />
     </session-factory>
 </hibernate-configuration>

2.4、开始测试

 package com.shore.test;

 import org.hibernate.cfg.Configuration;
 import org.hibernate.tool.hbm2ddl.SchemaExport;
 import org.junit.Test;

 /**
  * @author DSHORE/2019-9-19
  *
  */
 public class XMLTest {
     @Test
     public void test() {//简单测试，只创建表，不插入数据
                 //xml版，此处用Configuration()方法
         new SchemaExport(new Configuration().configure()).create(
                 false, true);
     }
 }

测试结果图：

　　　　

Hibernate一对一单向关联映射（Annotation+XML实现）：https://www.cnblogs.com/dshore123/p/11545058.html
Hibernate一对一双向关联映射（Annotation+XML实现）：https://www.cnblogs.com/dshore123/p/11545077.html

Hibernate多对一单向关联映射（Annotation+XML实现）：https://www.cnblogs.com/dshore123/p/11553213.html
Hibernate一对多单向关联映射（Annotation+XML实现）：https://www.cnblogs.com/dshore123/p/11553215.html
Hibernate一对多和多对一双向关联映射（Annotation+XML实现）：https://www.cnblogs.com/dshore123/p/11560433.html

Hibernate多对多单向关联映射（Annotation+XML实现）：https://www.cnblogs.com/dshore123/p/11568536.html
Hibernate多对多双向关联映射（Annotation+XML实现）：https://www.cnblogs.com/dshore123/p/11568963.html

原创作者：DSHORE 作者主页：http://www.cnblogs.com/dshore123/ 原文出自：https://www.cnblogs.com/dshore123/p/11553215.html 版权声明：欢迎转载，转载务必说明出处。（如果本文对您有帮助，可以点击一下右下角的 推荐，或评论，谢谢！）