component、composite、collection映射

1、component(组件)映射：在hibernate中,component是某个实体的逻辑组成部分，它与实体的根本区别是没有oid，component可以成为是值对象（DDD）

        采用component映射的好处：它实现了对象模型的细粒度划分，层次会更分明，复用率会更高

//model
public class Contact {
	
	private String email;
	
	private String address;
	
	private String zipCode;
	
	private String contactTel;

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	public String getZipCode() {
		return zipCode;
	}

	public void setZipCode(String zipCode) {
		this.zipCode = zipCode;
	}

	public String getContactTel() {
		return contactTel;
	}

	public void setContactTel(String contactTel) {
		this.contactTel = contactTel;
	}
}



public class User {
	
	private int id;
	
	private String name;
	
	private Contact contact;  // 持有对contact的引用
	
	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public Contact getContact() {
		return contact;
	}

	public void setContact(Contact contact) {
		this.contact = contact;
	}
}

//User.hbm.xml
<hibernate-mapping>
	<class name="com.bjsxt.hibernate.User" table="t_user">
		<id name="id">
			<generator class="native"/>
		</id>
		<property name="name" length = "10"/>
		<component name="contact"><!-- component映射联系类 -->
			<property name="email" length = "10"/>
			<property name="address" length = "10"/>
			<property name="zipCode" length = "10"/>
			<property name="contactTel" length = "10"/>
		</component>
	</class>
</hibernate-mapping>

//test
import org.hibernate.Session;

import junit.framework.TestCase;

public class ComponentMappingTest extends TestCase {

	public void testSave1() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			User user = new User();
			user.setName("张三");
			
			Contact contact = new Contact();
			contact.setAddress("xxxxx");
			contact.setEmail("[e-mail]");
			contact.setZipCode("1111111");
			contact.setContactTel("9999999");
			
			user.setContact(contact); //contact不是实体，是一个附属的类
			
			session.save(user); // update、save的对象为实体
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}		
}

2、复合（联合）主键映射：通常将复合主键相关的属性，单独放到一个类中
           * 此类必须实现序列化接口
           * 覆写hashcode和equals方法

//model
import java.io.Serializable;

@SuppressWarnings("serial")
public class FiscalYearPeriodPK implements Serializable { // 实现序列化接口

	//核算年
	private int fiscalYear;
	
	//核算月
	private int fiscalPeriod;

	public int getFiscalYear() {
		return fiscalYear;
	}

	public void setFiscalYear(int fiscalYear) {
		this.fiscalYear = fiscalYear;
	}

	public int getFiscalPeriod() {
		return fiscalPeriod;
	}

	public void setFiscalPeriod(int fiscalPeriod) {
		this.fiscalPeriod = fiscalPeriod;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + fiscalPeriod;
		result = prime * result + fiscalYear;
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		final FiscalYearPeriodPK other = (FiscalYearPeriodPK) obj;
		if (fiscalPeriod != other.fiscalPeriod)
			return false;
		if (fiscalYear != other.fiscalYear)
			return false;
		return true;
	}
}



import java.util.Date;
  
/**
 * 核算期间
 * @author wangy
 *
 */
public class FiscalYearPeriod {
	
	private FiscalYearPeriodPK fiscalYearPeriodPK;
	
	//开始日期
	private Date beginDate;
	
	//结束日期
	private Date endDate;
	
	//状态
	private String periodSts;

	public Date getBeginDate() {
		return beginDate;
	}

	public void setBeginDate(Date beginDate) {
		this.beginDate = beginDate;
	}

	public Date getEndDate() {
		return endDate;
	}

	public void setEndDate(Date endDate) {
		this.endDate = endDate;
	}

	public String getPeriodSts() {
		return periodSts;
	}

	public void setPeriodSts(String periodSts) {
		this.periodSts = periodSts;
	}

	public FiscalYearPeriodPK getFiscalYearPeriodPK() {
		return fiscalYearPeriodPK;
	}

	public void setFiscalYearPeriodPK(FiscalYearPeriodPK fiscalYearPeriodPK) {
		this.fiscalYearPeriodPK = fiscalYearPeriodPK;
	}
}

//FiscalYearPeriod.hbm.xml
<hibernate-mapping>
	<class name="com.bjsxt.hibernate.FiscalYearPeriod" table="t_fiscal_year_period">
		<composite-id name="fiscalYearPeriodPK"><!-- 映射联合主键 -->
			<key-property name="fiscalYear"/>
			<key-property name="fiscalPeriod"/>	
		</composite-id>
		<property name="beginDate"/>
		<property name="endDate"/>
		<property name="periodSts"/>
	</class>
</hibernate-mapping>

//test
import java.util.Date;

import org.hibernate.Session;

import junit.framework.TestCase;

public class CompositeMappingTest extends TestCase {

	public void testSave1() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			FiscalYearPeriod fiscalYearPeriod = new FiscalYearPeriod();// 实体类

			FiscalYearPeriodPK pk = new FiscalYearPeriodPK(); // 主键附属类
			pk.setFiscalYear(2008);
			pk.setFiscalPeriod(8);
			
			fiscalYearPeriod.setFiscalYearPeriodPK(pk);
			
			fiscalYearPeriod.setBeginDate(new Date());
			fiscalYearPeriod.setEndDate(new Date());
			fiscalYearPeriod.setPeriodSts("Y");
			
			session.save(fiscalYearPeriod);
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}		
	
	public void testLoad1() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			FiscalYearPeriodPK pk = new FiscalYearPeriodPK();
			pk.setFiscalYear(2008);
			pk.setFiscalPeriod(8);
			
			// 根据主键加载实体类
			FiscalYearPeriod fiscalYearPeriod = (FiscalYearPeriod)session.load(FiscalYearPeriod.class, pk);
			
			System.out.println(fiscalYearPeriod.getPeriodSts());
			
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}			
}

3、set、list、array、map 

//model
import java.util.List;
import java.util.Map;
import java.util.Set;

public class CollectionMapping {
	
	private int id;
	
	private String name;
	
	private Set<String> setValue;
	
	private List<String> listValue;
	
	private String[] arrayValue;
	
	private Map<String, String> mapValue;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String[] getArrayValue() {
		return arrayValue;
	}

	public void setArrayValue(String[] arrayValue) {
		this.arrayValue = arrayValue;
	}

	public void setListValue(List<String> listValue) {
		this.listValue = listValue;
	}

	public List<String> getListValue() {
		return listValue;
	}

	public void setSetValue(Set<String> setValue) {
		this.setValue = setValue;
	}

	public Set<String> getSetValue() {
		return setValue;
	}

	public void setMapValue(Map<String, String> mapValue) {
		this.mapValue = mapValue;
	}

	public Map<String, String> getMapValue() {
		return mapValue;
	}
}

//CollectionMapping.hbm.xml
<hibernate-mapping>
	<class name="com.bjsxt.hibernate.CollectionMapping" table="t_CollectionMapping">
		<id name="id">
			<generator class="native"/>
		</id>
		<property name="name"/>
		<set name="setValue" table="t_set_value"><!-- 映射集合Set，将CollectionMapping普通属性setValue映射成表 -->
			<key column="set_id"/><!-- 增加字段set_id，作为外键指向t_CollectionMapping -->
			<element type="string" column="set_value"/><!-- t_set_value表中保存集合Set的值 -->
		</set>
		<list name="listValue" table="t_list_value"><!-- List集合有顺序 -->
			<key column="list_id"/>
			<list-index column="list_index"/><!-- 加入索引，用于保证顺序 -->
			<element type="string" column="list_value"/>
		</list>
		<array name="arrayValue" table="t_array_value"><!-- 数组有顺序 -->
			<key column="array_id"/>
			<list-index column="array_index"/>
			<element type="string" column="array_value"/>
		</array>
		<map name="mapValue" table="t_map_value">
			<key column="map_id"/>
			<map-key type="string" column="map_key"/><!-- key-value -->
			<element type="string" column="map_value"/>
		</map>
	</class>
</hibernate-mapping>

//test
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.hibernate.Session;

import junit.framework.TestCase;

public class CollectionMappintTest extends TestCase {

	public void testSave1() {
		CollectionMapping c = new CollectionMapping();
		
		c.setName("xxx");
		
		Set<String> setValue = new HashSet<String>();
		setValue.add("a");
		setValue.add("b");
		c.setSetValue(setValue);
		
		List<String> listValue = new ArrayList<String>();
		listValue.add("c");
		listValue.add("d");
		c.setListValue(listValue);
		
		String[] arrayValue = new String[]{"e", "f"};
		c.setArrayValue(arrayValue);
		
		Map<String, String> mapValue = new HashMap<String, String>();
		mapValue.put("k1", "v1");
		mapValue.put("k2", "v2");
		c.setMapValue(mapValue);
		
		Session session = null;
		try { // 一般只需要包含会出异常代码
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			session.save(c);
			
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}	
	
	public void testLoad1() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			//根据主键加载实体类
			CollectionMapping c = (CollectionMapping)session.load(CollectionMapping.class, 1);
			System.out.println("name=" + c.getName());
			System.out.println("setvalue=" + c.getSetValue());
			System.out.println("mapvalue=" + c.getMapValue());
			System.out.println("listvalue=" + c.getListValue());
			System.out.println("arrayValue=" + c.getArrayValue().length);
			
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}
}