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.