分类：一对多自身双向关联关系
Java持久化类：
package com.hyy.hibernate.one_to_many.domain; import java.util.HashSet;
import java.util.Set; /**
* 分类：一对多自身双向关联关系
* User: HYY
* Date: 13-12-13
* Time: 下午7:32
* To change this template use File | Settings | File Templates.
*/
public class Category {
private Integer id;
private String name;
private Category parent;
private Set<Category> children = new HashSet<Category>(); 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 Category getParent() {
return parent;
} public void setParent(Category parent) {
this.parent = parent;
} public Set<Category> getChildren() {
return children;
} public void setChildren(Set<Category> children) {
this.children = children;
}
}
Category.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="com.hyy.hibernate.one_to_many.domain"> <class name="Category" dynamic-update="true"> <id name="id">
<generator class="native"/>
</id> <property name="name" length="50" access="property"/> <many-to-one name="parent" column="parent_id" /> <set name="children" inverse="true" cascade="save-update" lazy="true">
<key column="parent_id"/>
<one-to-many class="Category"/>
</set> </class> </hibernate-mapping>
一对多关联关系的one-to-many和many-to-one标签中的外键名要相同，比如本例的parent_id，一定是这两个，不能是其他了。
测试类：
public class CategoryTest {
@Test
public void test1() {
//食物
Category food = new Category();
food.setName("food");
//水果
Category fruit = new Category();
fruit.setName("fruit");
fruit.setParent(food);
food.getChildren().add(fruit);
//蔬菜
Category veg = new Category();
veg.setName("veg");
veg.setParent(food);
food.getChildren().add(veg);
//苹果
Category apple = new Category();
apple.setName("apple");
apple.setParent(fruit);
fruit.getChildren().add(apple);
Session session = HibernateUtil.getSession();
session.beginTransaction();
session.save(food);
session.getTransaction().commit();
}
}