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();
  }
}