Hibernate映射集合属性1__Set集合-蒲公英云

Hibernate映射集合属性1__Set集合

Set
    HashSet 无序,不重复
List
    有序,可重复
Map
    HashMap 无序,不重复(以key为准)
数组
e_user                    e_user_addressSet
id                            userId
name                        address
要说明的信息:
    a:集合表的名称(集合表)
    b:集合表中的外键(集合外键)
    c:集合表中的元素列(集合元素)
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 导入包 -->
<hibernate-mapping package="cn.itcast.e_hbm_collection">
    <!-- 类名 -->
    <class name="User" table="e_user">
        <id name="id" type="integer" column="id_">
            <generator class="native" />
        </id>
        <property name="name" type="string" column="name_" />
        <!-- addressSet属性,Set集合 -->
        <set name="addressSet" table="e_user_addressSet">
            <key column="userId"></key>
            <element type="string" column="address_"></element>
        </set>
    </class>
</hibernate-mapping>
package cn.itcast.e_hbm_collection;
import java.util.HashSet;
import java.util.Set;
public class User {
    private Integer id;
    private String name;
    private Set<String> addressSet = new HashSet<String>();// Set集合
    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 Set<String> getAddressSet() {
        return addressSet;
    }
    public void setAddressSet(Set<String> addressSet) {
        this.addressSet = addressSet;
    }
}
package cn.itcast.e_hbm_collection;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.junit.Test;
public class App {
    private static SessionFactory sessionFactory = new Configuration()//
            .configure()//
            .addClass(User.class)//
            .buildSessionFactory();
    @Test
    public void testSave() throws Exception {
        Session session = sessionFactory.openSession();
        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            // ------------------------------------
            // 操作
            // Set<String> set = new HashSet<String>();
            // set.add("骆家庄东苑");
            // set.add("文一新西路");
            // 构建对象
            User user = new User();
            user.setName("李四");
            user.getAddressSet().add("新青年厂场");
            user.getAddressSet().add("新塘路");
            // 保存
            session.save(user);
            // ------------------------------------
            tx.commit();
        } catch (RuntimeException e) {
            tx.rollback();
            throw e;
        } finally {
            session.close();
        }
    }
    @Test
    public void testGet() throws Exception {
        Session session = sessionFactory.openSession();
        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            // ------------------------------------
            // 获取数据
            User user = (User) session.get(User.class, 2);
            // 显示信息
            System.out.println(user.getId());
            System.out.println(user.getName());
            for (String s : user.getAddressSet()) {
                System.out.println(s);
            }
            // ------------------------------------
            tx.commit();
        } catch (RuntimeException e) {
            tx.rollback();
            throw e;
        } finally {
            session.close();
        }
    }
}