Hibernate之component、composite-id、collection映射

Hibernate之component、composite-id、collection映射

2008-11-26 21:26

1、component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

实体类：

package com.hibernate;

public class User {

private int id;

private String name;

private Contact contact;

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;
}

}

package com.hibernate;

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;
}
}

映射文件：

<hibernate-mapping>
<class name="com.hibernate.User" table="t_user">
   <id name="id">
    <generator class="native"/>
   </id>
   <property name="name"/>
   <component name="contact">
    <property name="email"/>
    <property name="address"/>
    <property name="zipCode"/>
    <property name="contactTel"/>
   </component>
</class>
</hibernate-mapping>

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

package com.hibernate;

import java.io.Serializable;

public class FiscalYearPeriodPK implements Serializable {

//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;
}

}

package com.hibernate;

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;
}
}

映射文件：

<hibernate-mapping>
<class name="com.bjsxt.hibernate.FiscalYearPeriod" table="t_fiscal_year_period">
   <composite-id name="fiscalYearPeriodPK">
    <key-property name="fiscalYear"/>
    <key-property name="fiscalPeriod"/>
   </composite-id>
   <property name="beginDate"/>
   <property name="endDate"/>
   <property name="periodSts"/>
</class>
</hibernate-mapping>

 

3、Collection的映射   set   list   array    map

实体类：

package com.hibernate;

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

public class CollectionMapping {

private int id;

private String name;

private Set setValue;

private List listValue;

private String[] arrayValue;

private Map 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 Set getSetValue() {
   return setValue;
}

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

public List getListValue() {
   return listValue;
}

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

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

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

public Map getMapValue() {
   return mapValue;
}

public void setMapValue(Map mapValue) {
   this.mapValue = mapValue;
}
}

映射文件：

<hibernate-mapping>
<class name="com.hibernate.CollectionMapping" table="t_CollectionMapping">
   <id name="id">
    <generator class="native"/>
   </id>
   <property name="name"/>
   <set name="setValue" table="t_set_value">
    <key column="set_id"/>
    <element type="string" column="set_value"/>
   </set>
   <list name="listValue" table="t_list_value">
    <key column="list_id"/>
    <list-index column="list_index"/>
    <element type="string" column="list_value"/>
   </list>
   <array name="arrayValue" table="t_array_value">
    <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"/>
    <element type="string" column="map_value"/>
   </map>
</class>
</hibernate-mapping