映射一对多-01单向cascadelazy

Posted 2020-06-26 shamgod

1.

 1 <?xml version="1.0"?>
 2 <!DOCTYPE hibernate-mapping
 3 PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 5 <hibernate-mapping >
 6 
 7    <class name="mypack.Monkey" table="MONKEYS">
 8      
 9       <id name="id" type="long" column="ID">
10         <generator class="increment"/>
11       </id>
12    
13       <property name="name" type="string" column="NAME" />
14       
15     <!--
16      <many-to-one
17         name="team"
18         column="TEAM_ID"
19         class="mypack.Team"
20         lazy="false"
21      />
22      -->
23 
24 <!-- mapping with cascade -->
25 <!---->
26       <many-to-one
27         name="team"
28         column="TEAM_ID"
29         class="mypack.Team"
30         cascade="save-update"  
31         lazy="false" 
32       />
33 
34 
35     </class>
36  
37 </hibernate-mapping>

 

2.

 1 package mypack;
 2 public class Monkey{
 3      private long id;
 4      private String name;
 5      private Team team;
 6 
 7     public Monkey() {}
 8     public Monkey(String name, Team team) {
 9        this.name = name;
10        this.team = team;
11     }
12    
13     public long getId() {
14         return this.id;
15     }
16     
17     public void setId(long id) {
18         this.id = id;
19     }
20     public String getName() {
21         return this.name;
22     }
23     
24     public void setName(String name) {
25         this.name = name;
26     }
27     public Team getTeam() {
28         return this.team;
29     }
30     
31     public void setTeam(Team team) {
32         this.team = team;
33     }
34 
35 
36 
37 
38 }

 

3.

 1 <?xml version="1.0"?>
 2 <!DOCTYPE hibernate-mapping
 3 PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 5 <hibernate-mapping >
 6 
 7   <class name="mypack.Team" table="TEAMS" >
 8     <id name="id" type="long" column="ID">
 9       <generator class="increment"/>
10     </id>
11 
12     <property name="name" type="string" column="NAME" />
13         
14   </class>
15 
16 </hibernate-mapping>

 

4.

 1 package mypack;
 2 public class Team {
 3      private long id;
 4      private String name;
 5 
 6     public Team() {
 7     }
 8 
 9     public Team(String name) {
10        this.name = name;
11     }
12    
13     public long getId() {
14         return this.id;
15     }
16     
17     public void setId(long id) {
18         this.id = id;
19     }
20     public String getName() {
21         return this.name;
22     }
23     
24     public void setName(String name) {
25         this.name = name;
26     }
27 
28 
29 
30 
31 }

 

5.

  1 package mypack;
  2 
  3 import org.hibernate.*;
  4 import org.hibernate.cfg.Configuration;
  5 import java.util.*;
  6 
  7 public class BusinessService{
  8   public static SessionFactory sessionFactory;
  9   static{
 10      try{
 11       // Create a configuration based on the properties file we‘ve put
 12        Configuration config = new Configuration();
 13        config.configure();
 14        sessionFactory = config.buildSessionFactory();
 15     }catch(RuntimeException e){e.printStackTrace();throw e;}
 16   }
 17 
 18   public List findMonkeysByTeam(Team team){
 19     Session session = sessionFactory.openSession();
 20     Transaction tx = null;
 21     try {
 22       tx = session.beginTransaction();
 23 
 24       List monkeys=session.createQuery("from Monkey as m where m.team.id="+team.getId())
 25                          .list();
 26       tx.commit();
 27       return monkeys;
 28     }catch (RuntimeException e) {
 29       if (tx != null) {
 30         tx.rollback();
 31       }
 32       throw e;
 33     } finally {
 34       session.close();
 35     }
 36   }
 37 
 38   public Team findTeam(long team_id){
 39     Session session = sessionFactory.openSession();
 40     Transaction tx = null;
 41     try {
 42       tx = session.beginTransaction();
 43       Team team=(Team)session.get(Team.class,new Long(team_id));
 44       tx.commit();
 45       return team;
 46     }catch (RuntimeException e) {
 47       if (tx != null) {
 48         tx.rollback();
 49       }
 50       throw e;
 51     } finally {
 52       session.close();
 53     }
 54   }
 55 
 56   public void saveTeamAndMonkeyWithCascade(){
 57     Session session = sessionFactory.openSession();
 58     Transaction tx = null;
 59     try {
 60       tx = session.beginTransaction();
 61 
 62       Team team=new Team("BULL");
 63       Monkey monkey1=new Monkey("Tom",team);
 64       Monkey monkey2=new Monkey("Mike",team);
 65 
 66       session.save(monkey1);
 67       session.save(monkey2);
 68 
 69       tx.commit();
 70 
 71     }catch (RuntimeException e) {
 72       if (tx != null) {
 73         tx.rollback();
 74       }
 75       e.printStackTrace();
 76     } finally {
 77       session.close();
 78     }
 79   }
 80 
 81   public void saveTeamAndMonkey(){
 82     Session session = sessionFactory.openSession();
 83     Transaction tx = null;
 84     try {
 85       tx = session.beginTransaction();
 86 
 87       Team team=new Team("DREAM");
 88       session.save(team);
 89 
 90       Monkey monkey1=new Monkey("Jack",team);
 91       Monkey monkey2=new Monkey("Bill",team);
 92       session.save(monkey1);
 93       session.save(monkey2);
 94       tx.commit();
 95 
 96     }catch (RuntimeException e) {
 97       if (tx != null) {
 98         tx.rollback();
 99       }
100       throw e;
101     } finally {
102       session.close();
103     }
104   }
105 
106   public void printMonkeys(List monkeys){
107       for (Iterator it = monkeys.iterator(); it.hasNext();) {
108          Monkey monkey=(Monkey)it.next();
109          System.out.println("Monkeys in "+monkey.getTeam().getName()+ " :"+monkey.getName());
110       }
111   }
112 
113    public void test(){
114       saveTeamAndMonkey();
115       saveTeamAndMonkeyWithCascade();
116       Team team=findTeam(1);
117       List monkeys=findMonkeysByTeam(team);
118       printMonkeys(monkeys);
119   }
120 
121   public static void main(String args[]){
122     new BusinessService().test();
123     sessionFactory.close();
124   }
125 }

 

6.

 1 <?xml version="1.0" encoding="utf-8" ?>
 2 <!DOCTYPE hibernate-configuration
 3  PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"
 4  "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
 5 <hibernate-configuration>
 6     <session-factory>
 7         <property name="dialect">
 8             org.hibernate.dialect.mysqlDialect
 9         </property>
10         <property name="connection.driver_class">
11             com.mysql.jdbc.Driver
12         </property>
13         <property name="connection.url">
14             jdbc:mysql://localhost:3306/sampledb
15         </property>
16         <property name="connection.username">
17             root
18         </property>
19         <property name="connection.password">
20             1234
21         </property>
22         <property name="show_sql">true</property>
23         <mapping resource="mypack/Team.hbm.xml" />
24         <mapping resource="mypack/Monkey.hbm.xml" />
25     </session-factory>
26 </hibernate-configuration>

 

7.

 1 drop database if exists SAMPLEDB;
 2 create database SAMPLEDB;
 3 use SAMPLEDB;
 4 
 5 create table TEAMS (
 6 ID bigint not null,
 7 NAME varchar(15), 
 8 primary key (ID));
 9 
10 create table MONKEYS (
11 ID bigint not null, 
12 NAME varchar(15),
13 TEAM_ID bigint, 
14 primary key (ID));
15 
16 alter table MONKEYS add index IDX_TEAM(TEAM_ID), 
17 add constraint FK_TEAM foreign key (TEAM_ID) references TEAMS (ID);

 

8.

 1 <?xml version="1.0"?>
 2 <project name="Learning Hibernate" default="prepare" basedir=".">
 3 
 4   <!-- Set up properties containing important project directories -->
 5   <property name="source.root" value="5.1/src"/>
 6   <property name="class.root" value="5.1/classes"/>
 7   <property name="lib.dir" value="lib"/>
 8   <property name="schema.dir" value="5.1/schema"/>
 9 
10   <!-- Set up the class path for compilation and execution -->
11   <path id="project.class.path">
12       <!-- Include our own classes, of course -->
13       <pathelement location="${class.root}" />
14       <!-- Include jars in the project library directory -->
15       <fileset dir="${lib.dir}">
16         <include name="*.jar"/>
17       </fileset>
18   </path>
19 
20   <!-- Create our runtime subdirectories and copy resources into them -->
21   <target name="prepare" description="Sets up build structures">
22     <delete dir="${class.root}"/>
23     <mkdir dir="${class.root}"/>
24 
25     <!-- Copy our property files and O/R mappings for use at runtime -->
26     <copy todir="${class.root}" >
27       <fileset dir="${source.root}" >
28         <include name="**/*.properties"/>
29         <include name="**/*.hbm.xml"/>
30         <include name="**/*.cfg.xml"/>
31       </fileset>
32     </copy>
33   </target>
34 
35 
36 
37  <!-- Compile the java source of the project -->
38   <target name="compile" depends="prepare"
39           description="Compiles all Java classes">
40     <javac srcdir="${source.root}"
41            destdir="${class.root}"
42            debug="on"
43            optimize="off"
44            deprecation="on">
45       <classpath refid="project.class.path"/>
46     </javac>
47   </target> 
48 
49 
50  <target name="run" description="Run a Hibernate sample"
51           depends="compile">
52     <java classname="mypack.BusinessService" fork="true">
53       <classpath refid="project.class.path"/>
54     </java>
55   </target>
56 
57 </project>