【學習筆記】Hibernate映射List、Map、數組、Set、Bag的具體操作

已經給出了所有需要的代碼，資料庫的配置這些就不給啦

注意：使用集合映射類聲明時要注意使用接口而不是具體實作類。因為經過Session操作後，集合就變成了hibernate自己的集合實作類。

實體類：User.java

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; // 數組
	private Map<String, String> addressMap = new HashMap<String, String>();
	private List<String> addressBag = new ArrayList<String>();

	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;
	}


}
           

映射檔案：User.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="cn.itcast.e_hbm_collection">
	
	<class name="User" table="user">
		<id name="id">
        	<generator class="native"></generator>
		</id>
		<property name="name"/>
		
		<!-- addressSet屬性，Set集合 
			table屬性：集合表的名稱
			key子元素：集合外鍵的列名
			element子元素：存放集合元素的列的資訊
			sort屬性："unsorted|natural|comparatorClass"
				預設為：unsorted
			order-by屬性：寫的是order by 子句，是SQL語句，是操作的集合表。
				這是在查詢資料時指定orderby子句。
		-->
		<set name="addressSet" table="user_addressSet" order-by="address ASC">
			<key column="userId"></key>
			<element type="string" column="address"></element>
		</set>
		
		<!-- addressList屬性，List集合 
			list-index：用于存放索引的列
		-->
		<list name="addressList" table="user_addressList">
			<key column="userId"></key>
			<list-index column="idx"></list-index>
			<element type="string" column="address"></element>
		</list>
		
		<!-- addressArray屬性，數組。與List的映射基本一緻 -->
		<array name="addressArray" table="user_addressArray">
			<key column="userId"></key>
			<list-index column="idx"></list-index>
			<element type="string" column="address"></element>
		</array>
		
		<!-- addressMap屬性，Map集合 -->
		<map name="addressMap" table="user_addressMap">
			<key column="userId"></key>
			<map-key type="string" column="key_"></map-key>
			<element type="string" column="address"></element>
		</map>
		
		<!-- addressBag屬性，Bag集合：無序，可重複。與Set集合的映射基本一緻 -->
		<bag name="addressBag" table="user_addressBag">
			<key column="userId"></key>
			<element type="string" column="address"></element>
		</bag>
		
	</class>
	
</hibernate-mapping>
           

測試類：App.java

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import java.util.TreeSet;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.junit.Test;

public class App {

	private static SessionFactory sessionFactory = new Configuration()//
			.configure()//
			.addClass(User.class)// 添加Hibernate實體類（加載對應的映射檔案）
			.buildSessionFactory();

	@Test
	public void testSave() throws Exception {
		Session session = sessionFactory.openSession();
		session.beginTransaction();
		// --------------------------------------------

		// 建構對象
		User user = new User();
		user.setName("張天");
		// >> Set集合
		user.setAddressSet(new TreeSet<String>()); // 當設定了sort屬性時，就要使用SortedSet類型
		user.getAddressSet().add("2嶺南");
		user.getAddressSet().add("1小新塘");
		// >> List集合
		user.getAddressList().add("嶺南");
		user.getAddressList().add("小新塘");
		user.getAddressList().add("小新塘");
		// >> 數組
		user.setAddressArray(new String[] { "嶺南", "小新塘" });
		// >> Map集合
		user.getAddressMap().put("公司", "嶺南");
		user.getAddressMap().put("家庭", "小新塘");
		// >> Bag集合
		user.getAddressBag().add("嶺南");
		user.getAddressBag().add("小新塘");
		user.getAddressBag().add("小新塘");

		// 儲存
		session.save(user);

		// --------------------------------------------
		session.getTransaction().commit();
		session.close();
	}

	@Test
	public void testGet() throws Exception {
		Session session = sessionFactory.openSession();
		session.beginTransaction();
		// --------------------------------------------

		// 擷取資料
		User user = (User) session.get(User.class, 9);

		// 顯示資訊
		System.out.println(user.getName());
		System.out.println(user.getAddressSet());
		System.out.println(user.getAddressList());
		System.out.println(Arrays.toString(user.getAddressArray()));
		System.out.println(user.getAddressMap());
		System.out.println(user.getAddressBag());

		// --------------------------------------------
		session.getTransaction().commit();
		session.close();
	}
}