Hibernate逍遥游记-第5章映射一对多-02双向(<set>、<key>、<one-to-many>、inverse、cascade="all-delete-orphan")

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" type="string" column="NAME" />

       <many-to-one
         name="team"
         column="TEAM_ID"
         class="mypack.Team"
         cascade="save-update"
        />

     </class>

 </hibernate-mapping>

2.

 package mypack;

 public class Monkey {

      private long id;
      private String name;
      private Team team;

     public Monkey() {}

     public Monkey(String name, Team team) {
        this.name = name;
        this.team = team;
     }

     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 Team getTeam() {
         return this.team;
     }

     public void setTeam(Team team) {
         this.team = team;
     }
 }

3.

 <?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.Team" table="TEAMS" >
     <id name="id" type="long" column="ID">
       <generator class="increment"/>
     </id>

     <property name="name" type="string" column="NAME" />
 <!--
     <set
         name="monkeys"
         cascade="all-delete-orphan"
         inverse="true"
          >

         <key column="TEAM_ID" />
         <one-to-many class="mypack.Monkey" />
      </set>
 -->
     <set
         name="monkeys"
         inverse="true"
         cascade="save-update"
         >

         <key column="TEAM_ID" />
         <one-to-many class="mypack.Monkey" />
      </set>   

   </class>
 </hibernate-mapping>

4.

 package mypack;

 import java.util.HashSet;
 import java.util.Set;

 public class Team{

      private long id;
      private String name;
      private Set monkeys = new HashSet();

     public Team() {}

     public Team(String name, Set monkeys) {
        this.name = name;
        this.monkeys = monkeys;
     }

     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 Set getMonkeys() {
         return this.monkeys;
     }

     public void setMonkeys(Set monkeys) {
         this.monkeys = monkeys;
     }
 }

5.

 <?xml version="1.0" encoding="utf-8" ?>
 <!DOCTYPE hibernate-configuration
  PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"
  "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
 <hibernate-configuration>
     <session-factory>
         <property name="dialect">
             org.hibernate.dialect.MySQLDialect
         </property>
         <property name="connection.driver_class">
             com.mysql.jdbc.Driver
         </property>
         <property name="connection.url">
             jdbc:mysql://localhost:3306/sampledb
         </property>
         <property name="connection.username">
             root
         </property>
         <property name="connection.password">
             1234
         </property>
         <property name="show_sql">true</property>
         <mapping resource="mypack/Team.hbm.xml" />
         <mapping resource="mypack/Monkey.hbm.xml" />
     </session-factory>
 </hibernate-configuration>

6.

 package mypack;

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

 public class BusinessService{
   public static SessionFactory sessionFactory;
   private Long idOfTom;
   private Long idOfBULL;
   private Long idOfJack;
   private Long idOfDREAM;

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

   public void printMonkeysOfTeam(Long teamId){
     Session session = sessionFactory.openSession();
     Transaction tx = null;
     try {
       tx = session.beginTransaction();
       Team team=(Team)session.get(Team.class,teamId);
       printMonkeys(team.getMonkeys());
       tx.commit();
     }catch (RuntimeException e) {
       if (tx != null) {
          tx.rollback();
       }
       throw e;
     } finally {
        session.close();
     }
   }

   public void saveTeamAndMonkeyWithCascade(){
     Session session = sessionFactory.openSession();
     Transaction tx = null;
     try {
       tx = session.beginTransaction();

       Team team=new Team("BULL",new HashSet());
       Monkey monkey=new Monkey();
       monkey.setName("Tom");

       monkey.setTeam(team);
       team.getMonkeys().add(monkey);

       session.save(team);
       tx.commit();

       idOfBULL=team.getId();
       idOfTom=monkey.getId();  

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

     public void associateTeamAndMonkey(){
     Session session = sessionFactory.openSession();
     Transaction tx = null;
     try {
       tx = session.beginTransaction();
       Team team=(Team)session.load(Team.class,idOfDREAM);
       Monkey monkey=(Monkey)session.load(Monkey.class,idOfJack);
       monkey.setTeam(team);
       team.getMonkeys().add(monkey);
       tx.commit();
     }catch (RuntimeException e) {
       if (tx != null) {
         tx.rollback();
       }
        e.printStackTrace();
     } finally {
       session.close();
     }
   }

   public void saveTeamAndMonkeySeparately(){
     Session session = sessionFactory.openSession();
     Transaction tx = null;
     try {
       tx = session.beginTransaction();

       Team team=new Team("DREAM",new HashSet());
       Monkey monkey=new Monkey();
       monkey.setName("Jack");

       session.save(team);
       session.save(monkey);

       tx.commit();
       idOfDREAM=team.getId();
       idOfJack=monkey.getId(); 

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

   public void deleteTeam(Long teamId){
     Session session = sessionFactory.openSession();
     Transaction tx = null;
     try {
       tx = session.beginTransaction();
       Team team=(Team)session.load(Team.class,teamId);
       session.delete(team);
       tx.commit();

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

   public void removeMonkeyFromTeam(Long teamId){
     Session session = sessionFactory.openSession();
     Transaction tx = null;
     try {
       tx = session.beginTransaction();
       Team team=(Team)session.load(Team.class,teamId);
       Monkey monkey=(Monkey)team.getMonkeys().iterator().next();

       //解除team和Monkey的关联关系
       team.getMonkeys().remove(monkey);
       monkey.setTeam(null);
       tx.commit();

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

   public void printMonkeys(Set monkeys){
       for (Iterator it = monkeys.iterator(); it.hasNext();) {
          Monkey monkey=(Monkey)it.next();
          System.out.println("Monkeys in "+monkey.getTeam().getName()+ " :"+monkey.getName());
       }
   }

    public void saveTeamAndMonkeyWithInverse(){
       saveTeamAndMonkeySeparately();
       associateTeamAndMonkey();
    }
    public void test(){

       saveTeamAndMonkeyWithCascade();
       saveTeamAndMonkeyWithInverse();
       printMonkeysOfTeam(idOfBULL);
       //deleteTeam(idOfDREAM);
       removeMonkeyFromTeam(idOfBULL);
   }

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