Hibernate映射集合属性2__List、Map、数组、Bag等

妖狐艹你老母 2022-06-16 05:07 234阅读 0赞

Set
    	HashSet 无序,不重复
    	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)
    	
    List
    	有序,可重复
    	e_user					e_user_addressList
    	id							userId
    	name						address
    								idx
    	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)
    		e:集合元素的索引列
    
    Map
    	HashMap 无序,不重复(以key为准)
    	e_user					e_user_addressMap
    	id							userId
    	name						address
    								key_
    	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)
    		e:集合元素的键
    -------------------------------------------------------------------
    
    数组
    	有序,可重复
    	e_user					e_user_addressArray
    	id							userId
    	name						address
    								idx
    	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)
    		e:集合元素的索引列
    
    Bag
    	无序,可重复
    	List
    	e_user					e_user_addressBag
    	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)
    
    使用集合属性时,一定要使用接口,而不能声明为具体的实现类。
    因为经过Session操作后,集合变成了Hibernate自已的集合实现类。

映射文件

<?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="cn.itcast.e_hbm_collection">
    	
    	<class name="User" table="e_user">
    		<id name="id" type="integer" column="id_">
    			<generator class="native" />
    		</id>
    		<property name="name" type="string" column="name_" />
    		
    		
    		<set name="addressSet" table="e_user_addressSet">
    			<key column="userId"></key>
    			<element type="string" column="address_"></element>
    		</set>
    
    		
    		<list name="addressList" table="e_user_addressList">
    			<key column="userId" />
    			<list-index column="idx_"></list-index>
    			<element type="string" column="address_" />
    		</list>
    		
    		
    		<array name="addressArray" table="e_user_addressArray">
    			<key column="userId"></key>
    			<index type="string" column="idx_"></index>
    			<element type="string" column="address_"></element>
    		</array>
    		
    		
    		<map name="addressMap" table="e_user_addressMap">
    			<key column="userId"></key>
    			<map-key type="string" column="key_"></map-key>
    			<element type="string" column="address_"></element>
    		</map>
    		
    		
    		<bag name="addressBag" table="e_user_addressBag">
    			<key column="userId"></key>
    			<element type="string" column="address_"></element>
    		</bag>
    	</class>
    </hibernate-mapping>

实体类

package cn.itcast.e_hbm_collection;
    
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.HashSet;
    import java.util.List;
    import java.util.Map;
    import java.util.Set;
    
    public class User {
    	private Integer id;
    	private String name;
    
    	private Set<String> addressSet = new HashSet<String>();// Set集合
    	private List<String> addressList = new ArrayList<String>();// List集合
    	private String[] addressArray;// 数组
    	private Map<String, String> addressMap = new HashMap<String, String>();// Map集合
    	private List<String> addressBag = new ArrayList<String>();// Bag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;
    	}
    
    	public List<String> getAddressList() {
    		return addressList;
    	}
    
    	public void setAddressList(List<String> addressList) {
    		this.addressList = addressList;
    	}
    
    	public String[] getAddressArray() {
    		return addressArray;
    	}
    
    	public void setAddressArray(String[] addressArray) {
    		this.addressArray = addressArray;
    	}
    
    	public Map<String, String> getAddressMap() {
    		return addressMap;
    	}
    
    	public void setAddressMap(Map<String, String> addressMap) {
    		this.addressMap = addressMap;
    	}
    
    	public List<String> getAddressBag() {
    		return addressBag;
    	}
    
    	public void setAddressBag(List<String> addressBag) {
    		this.addressBag = addressBag;
    	}
    
    }

保存获取操作类

package cn.itcast.e_hbm_collection;
    
    import java.util.Arrays;
    import java.util.HashSet;
    import java.util.Set;
    
    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");
    			// >> Set集合
    			 user.getAddressSet().add("新青年厂场");
    			 user.getAddressSet().add("新塘路");
    			// >> List集合
    			 user.getAddressList().add("新青年厂场");
    			 user.getAddressList().add("新塘路");
    			 user.getAddressList().add("新塘路");
    			// >> 数组
    			 String[] string = { "新青年厂场", "新塘路", "新塘路" };
    			 user.setAddressArray(string);
    			// >> Map集合
    			 user.getAddressMap().put("公司", "新青年厂场");
    			 user.getAddressMap().put("家庭", "骆家庄东苑");
    			// >> Bag集合
    			user.getAddressBag().add("新青年厂场");
    			user.getAddressBag().add("新塘路");
    			user.getAddressBag().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, 1);
    
    			// 显示信息
    			System.out.println(user.getId());
    			System.out.println(user.getName());
    			// >> Set集合
    			 System.out.println(user.getAddressSet());
    			// >> List集合
    			 System.out.println(user.getAddressList().get(0));
    			// >> 数组
    			 System.out.println(Arrays.toString(user.getAddressArray()));
    			// >> Map集合
    			 System.out.println(user.getAddressMap());
    			// >> Bag集合
    			System.out.println(user.getAddressBag());
    
    			// ------------------------------------
    			tx.commit();
    		} catch (RuntimeException e) {
    			tx.rollback();
    			throw e;
    		} finally {
    			session.close();
    		}
    	}
    }