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