Hibernate逍遥游记-第5章映射一对多-01单向<many-to-one>、cascade="save-update"、lazy、TransientObjectException

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"
        lazy="false"
     />
     -->

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


    </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" />
        
  </class>

</hibernate-mapping>

4.

package mypack;
public class Team {
     private long id;
     private String name;

    public Team() {
    }

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




}

5.

package mypack;

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

public class BusinessService{
  public static SessionFactory sessionFactory;
  static{
     try{
      // Create a configuration based on the properties file we've put
       Configuration config = new Configuration();
       config.configure();
       sessionFactory = config.buildSessionFactory();
    }catch(RuntimeException e){e.printStackTrace();throw e;}
  }

  public List findMonkeysByTeam(Team team){
    Session session = sessionFactory.openSession();
    Transaction tx = null;
    try {
      tx = session.beginTransaction();

      List monkeys=session.createQuery("from Monkey as m where m.team.id="+team.getId())
                         .list();
      tx.commit();
      return monkeys;
    }catch (RuntimeException e) {
      if (tx != null) {
        tx.rollback();
      }
      throw e;
    } finally {
      session.close();
    }
  }

  public Team findTeam(long team_id){
    Session session = sessionFactory.openSession();
    Transaction tx = null;
    try {
      tx = session.beginTransaction();
      Team team=(Team)session.get(Team.class,new Long(team_id));
      tx.commit();
      return team;
    }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");
      Monkey monkey1=new Monkey("Tom",team);
      Monkey monkey2=new Monkey("Mike",team);

      session.save(monkey1);
      session.save(monkey2);

      tx.commit();

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

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

      Team team=new Team("DREAM");
      session.save(team);

      Monkey monkey1=new Monkey("Jack",team);
      Monkey monkey2=new Monkey("Bill",team);
      session.save(monkey1);
      session.save(monkey2);
      tx.commit();

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

  public void printMonkeys(List 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 test(){
      saveTeamAndMonkey();
      saveTeamAndMonkeyWithCascade();
      Team team=findTeam(1);
      List monkeys=findMonkeysByTeam(team);
      printMonkeys(monkeys);
  }

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

6.

<?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>

7.

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

create table TEAMS (
ID bigint not null,
NAME varchar(15), 
primary key (ID));

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

alter table MONKEYS add index IDX_TEAM(TEAM_ID), 
add constraint FK_TEAM foreign key (TEAM_ID) references TEAMS (ID);

8.

<?xml version="1.0"?>
<project name="Learning Hibernate" default="prepare" basedir=".">

  <!-- Set up properties containing important project directories -->
  <property name="source.root" value="5.1/src"/>
  <property name="class.root" value="5.1/classes"/>
  <property name="lib.dir" value="lib"/>
  <property name="schema.dir" value="5.1/schema"/>

  <!-- Set up the class path for compilation and execution -->
  <path id="project.class.path">
      <!-- Include our own classes, of course -->
      <pathelement location="${class.root}" />
      <!-- Include jars in the project library directory -->
      <fileset dir="${lib.dir}">
        <include name="*.jar"/>
      </fileset>
  </path>

  <!-- Create our runtime subdirectories and copy resources into them -->
  <target name="prepare" description="Sets up build structures">
    <delete dir="${class.root}"/>
    <mkdir dir="${class.root}"/>

    <!-- Copy our property files and O/R mappings for use at runtime -->
    <copy todir="${class.root}" >
      <fileset dir="${source.root}" >
        <include name="**/*.properties"/>
        <include name="**/*.hbm.xml"/>
        <include name="**/*.cfg.xml"/>
      </fileset>
    </copy>
  </target>



 <!-- Compile the java source of the project -->
  <target name="compile" depends="prepare"
          description="Compiles all Java classes">
    <javac srcdir="${source.root}"
           destdir="${class.root}"
           debug="on"
           optimize="off"
           deprecation="on">
      <classpath refid="project.class.path"/>
    </javac>
  </target> 


 <target name="run" description="Run a Hibernate sample"
          depends="compile">
    <java classname="mypack.BusinessService" fork="true">
      <classpath refid="project.class.path"/>
    </java>
  </target>

</project>

 9.TransientObjectException