Hibernate逍遥游记-第13章 映射实体关联关系-001用外键映射一对一(<many-to-one unique="true">、<one-to-one>)

1.

 <?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 >

   <class name="mypack.Monkey" table="MONKEYS" >
     <id name="id" type="long" column="ID">
       <generator class="increment"/>
     </id>

     <property name="name" column="NAME" type="string" />

     <many-to-one name="homeAddress"
         class="mypack.Address"
         column="HOME_ADDRESS_ID"
         cascade="all"
         unique="true"
     />

     <many-to-one name="comAddress"
         class="mypack.Address"
         column="COM_ADDRESS_ID"
         cascade="all"
         unique="true"
     />

   </class>

 </hibernate-mapping>

2.

 <?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 >

   <class name="mypack.Address" table="ADDRESSES" >
     <id name="id" type="long" column="ID">
       <generator class="increment"/>
     </id>

     <property name="city" column="CITY" type="string" />
     <property name="province" column="PROVINCE" type="string" />
     <property name="street" column="STREET" type="string" />
     <property name="zipcode" column="ZIPCODE" type="string" />

     <one-to-one name="monkey"
         class="mypack.Monkey"
        property-ref="homeAddress"
     />

   </class>
 </hibernate-mapping>

3.

 package mypack;

 public class Monkey {

     private Long id;
     private String name;
     private Address homeAddress;
     private Address comAddress;

     public Monkey(String name, Address homeAddress, Address comAddress) {
         this.name = name;
         this.homeAddress = homeAddress;
         this.comAddress = comAddress;
     }

     /** default constructor */
     public Monkey() {
     }

     /** minimal constructor */
     public Monkey(Address homeAddress, Address comAddress) {
         this.homeAddress = homeAddress;
         this.comAddress = comAddress;
     }

     public Long getId() {
         return this.id;
     }

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

     public String getName() {
         return this.name;
     }

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

     public mypack.Address getHomeAddress() {
         return this.homeAddress;
     }

     public void setHomeAddress(mypack.Address homeAddress) {
         this.homeAddress = homeAddress;
     }

     public mypack.Address getComAddress() {
         return this.comAddress;
     }

     public void setComAddress(mypack.Address comAddress) {
         this.comAddress = comAddress;
     }

 }

4.

 package mypack;

 public class Address {
     private Long id;
     private String street;
     private String city;
     private String province;
     private String zipcode;
     private Monkey monkey;

     /** full constructor */
     public Address(String province,String city,String street, String zipcode, Monkey monkey) {
         this.street = street;
         this.city = city;
         this.province = province;
         this.zipcode = zipcode;
         this.monkey = monkey;
     }

     /** default constructor */
     public Address() {
     }

     public String getStreet() {
         return this.street;
     }

     public void setStreet(String street) {
         this.street = street;
     }

     public Long getId() {
         return this.id;
     }

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

     public String getCity() {
         return this.city;
     }

     public void setCity(String city) {
         this.city = city;
     }

     public String getProvince() {
         return this.province;
     }

     public void setProvince(String province) {
         this.province = province;
     }

     public String getZipcode() {
         return this.zipcode;
     }

     public void setZipcode(String zipcode) {
         this.zipcode = zipcode;
     }

     public mypack.Monkey getMonkey() {
         return this.monkey;
     }

     public void setMonkey(mypack.Monkey monkey) {
         this.monkey = monkey;
     }

 }

5.

 package mypack;

 import org.hibernate.*;
 import org.hibernate.cfg.Configuration;
 import java.util.*;

 public class BusinessService{
   public static SessionFactory sessionFactory;
   static{
      try{
        Configuration config = new Configuration().configure();
        sessionFactory = config.buildSessionFactory();
     }catch(RuntimeException e){e.printStackTrace();throw e;}
   }

   public void saveMonkey(Monkey monkey){
     Session session = sessionFactory.openSession();
     Transaction tx = null;
     try {
       tx = session.beginTransaction();
       session.save(monkey);
       tx.commit();

     }catch (RuntimeException e) {
       if (tx != null) {
         tx.rollback();
       }
       throw e;
     } finally {
       session.close();
     }
   }

  public Monkey loadMonkey(Long id){
     Session session = sessionFactory.openSession();
     Transaction tx = null;
     try {
       tx = session.beginTransaction();
       Monkey monkey=(Monkey)session.get(Monkey.class,id);
       Hibernate.initialize(monkey.getHomeAddress());
       Hibernate.initialize(monkey.getComAddress());
       tx.commit();
       return monkey;

     }catch (RuntimeException e) {
       if (tx != null) {
         tx.rollback();
       }
       throw e;
     } finally {
       session.close();
     }
   }

   public void printMonkey(Monkey monkey) {
     Address homeAddress=monkey.getHomeAddress();
     Address comAddress=monkey.getComAddress();
     System.out.println("Home Address of "+monkey.getName()+" is: "
       +homeAddress.getProvince()+" "
       +homeAddress.getCity()+" "
       +homeAddress.getStreet());

     System.out.println("Company Address of "+monkey.getName()+" is: "
       +comAddress.getProvince()+" "
       +comAddress.getCity()+" "
       +comAddress.getStreet());

     if(homeAddress.getMonkey()==null)
       System.out.println("Can not naviagte from homeAddress to Monkey.");

     if(comAddress.getMonkey()==null)
       System.out.println("Can not naviagte from comAddress to Monkey.");

   }

  public void test(){

       Monkey monkey=new Monkey();
       Address homeAddress=new Address("province1","city1","street1","100001",monkey);
       Address comAddress=new Address("province2","city2","street2","200002",monkey);
       monkey.setName("Tom");
       monkey.setHomeAddress(homeAddress);
       monkey.setComAddress(comAddress);

       saveMonkey(monkey);
       monkey=loadMonkey(monkey.getId());
       printMonkey(monkey);

   }

   public static void main(String args[]) {
     new BusinessService().test();
     sessionFactory.close();
   }
 }

6.

 drop database if exists SAMPLEDB;
 create database SAMPLEDB;
 use SAMPLEDB;

 create table MONKEYS (
    ID bigint not null,
    NAME varchar(15),
    HOME_ADDRESS_ID bigint unique,
    COM_ADDRESS_ID bigint unique,
    primary key (ID)
 );

 create table ADDRESSES(
   ID bigint not null,
   CITY varchar(128),
   STREET varchar(128),
   PROVINCE varchar(128),
   ZIPCODE varchar(6),
   primary key(ID)
 );

 alter table MONKEYS add index IDX_HOME_ADDRESS(HOME_ADDRESS_ID),
 add constraint FK_HOME_ADDRESS foreign key (HOME_ADDRESS_ID) references ADDRESSES(ID);

 alter table MONKEYS add index IDX_COM_ADDRESS(COM_ADDRESS_ID),
 add constraint FK_COM_ADDRESS foreign key (COM_ADDRESS_ID) references ADDRESSES(ID);

7.