1 package com.yl.hibernate.entities.n21.both;
 2
 3 import java.util.HashSet;
 4 import java.util.Set;
 5
 6 public class Customer {
 7
 8     private Integer customerId;
 9     private String customerName;
10     /**
11      * 1.声明集合类型时，需使用接口类型，因为hibernate在获取集合类型时，返回的是Hibernate内置的集合类型，而不是JavaSE一个标准的集合
12      * 2.需要把集合进行初始化，可以防止发生空指针异常
13      */
14     private Set<Order> orders = new HashSet<Order>();
15
16     public Integer getCustomerId() {
17         return customerId;
18     }
19     public void setCustomerId(Integer customerId) {
20         this.customerId = customerId;
21     }
22     public String getCustomerName() {
23         return customerName;
24     }
25     public void setCustomerName(String customerName) {
26         this.customerName = customerName;
27     }
28     public Set<Order> getOrders() {
29         return orders;
30     }
31     public void setOrders(Set<Order> orders) {
32         this.orders = orders;
33     }
34
35
36 }

 1 package com.yl.hibernate.entities.n21.both;
 2
 3 public class Order {
 4
 5     private Integer orderId;
 6     private String orderName;
 7
 8     private Customer customer;
 9
10     public Integer getOrderId() {
11         return orderId;
12     }
13
14     public void setOrderId(Integer orderId) {
15         this.orderId = orderId;
16     }
17
18     public String getOrderName() {
19         return orderName;
20     }
21
22     public void setOrderName(String orderName) {
23         this.orderName = orderName;
24     }
25
26     public Customer getCustomer() {
27         return customer;
28     }
29
30     public void setCustomer(Customer customer) {
31         this.customer = customer;
32     }
33
34
35 }

 1 <?xml version="1.0"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 3 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 4 <!-- Generated 2014-11-26 19:19:40 by Hibernate Tools 3.4.0.CR1 -->
 5 <hibernate-mapping>
 6     <class name="com.yl.hibernate.entities.n21.both.Customer" table="CUSTOMERS">
 7         <id name="customerId" type="java.lang.Integer">
 8             <column name="CUSTOMER_ID" />
 9             <generator class="native" />
10         </id>
11         <property name="customerName" type="java.lang.String">
12             <column name="CUSTOMER_NAME" />
13         </property>
14
15         <!-- 映射1对多的那个集合属性 -->
16         <!-- set: 映射set类型的属性，table:set中的元素对应的记录放在哪一个数据表中，该值需要和多对一的多的那个表的名字一致 -->
17         <!-- inverse：指定由哪一方来维护映射关系。通常设置为true，以指定由多的一方来维护关联关系 -->
18         <!-- cascade：设定级联操作。 开发时不建议设定该属性。建议使用手工的方式来处理
19             delete
20             delete-orphan
21             save-update
22         -->
23         <!-- order-by 在查询时对集合中的元素排序，order-by中使用的是表的字段名，而不是持久化类的属性名 -->
24         <set name="orders" table="ORDERS" inverse="true" cascade="delete-orphan" order-by="ORDER_NAME DESC">
25             <!-- key：指定多的表汇总的外键列的名字 -->
26             <key column="CUSTOMER_ID"></key>
27             <!-- 指定映射类型 -->
28             <one-to-many class="com.yl.hibernate.entities.n21.both.Order"/>
29         </set>
30     </class>
31 </hibernate-mapping>

 1 <?xml version="1.0"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 3 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 4 <!-- Generated 2014-11-26 19:19:40 by Hibernate Tools 3.4.0.CR1 -->
 5 <hibernate-mapping>
 6     <class name="com.yl.hibernate.entities.n21.both.Order" table="ORDERS">
 7         <id name="orderId" type="java.lang.Integer">
 8             <column name="ORDER_ID" />
 9             <generator class="native" />
10         </id>
11         <property name="orderName" type="java.lang.String">
12             <column name="ORDER_NAME" />
13         </property>
14         <!-- 映射多对一的映射关系。使用many-to-one 来映射多对一的关联关系
15             name：多这一端关联的一那一端的属性的名字
16             class：一那一端的属性对应的类名
17             column：一那一端在多的一端对应的数据表中的外键的名字
18          -->
19         <many-to-one name="customer" class="com.yl.hibernate.entities.n21.both.Customer" column="CUSTOMER_ID">
20         </many-to-one>
21
22     </class>
23 </hibernate-mapping>