Hibernate逍遥游记-第13章 映射实体关联关系-006双向多对多(分解为一对多)

1.

 

 

2.

 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     <id name="id" type="long" column="ID">
 9       <generator class="increment"/>
10     </id>
11 
12    <property name="name" column="NAME" type="string" />
13     
14    <set name="learnings" lazy="true" inverse="true" cascade="save-update">
15         <key column="MONKEY_ID" />
16         <one-to-many  class="mypack.Learning" />
17    </set>
18      
19   </class>
20 
21 </hibernate-mapping>

 

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.Teacher" table="TEACHERS" >
 8     <id name="id" type="long" column="ID">
 9       <generator class="increment"/>
10     </id>
11 
12     <property name="name" column="NAME" type="string" />
13     
14      <set name="learnings" lazy="true" inverse="true" cascade="save-update">
15         <key column="TEACHER_ID" />
16         <one-to-many  class="mypack.Learning" />
17      </set>
18  
19   </class>
20 </hibernate-mapping>

 

4.

 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.Learning" table="LEARNING" >
 8     <id name="id" type="long" column="ID">
 9       <generator class="increment"/>
10     </id>
11 
12     <property name="gongfu" column="GONGFU" type="string" />
13     
14     <many-to-one name="monkey" column="MONKEY_ID" class="mypack.Monkey" not-null="true" />
15     <many-to-one name="teacher" column="TEACHER_ID" class="mypack.Teacher" not-null="true" />
16 
17  
18   </class>
19 </hibernate-mapping>

5.

 1 package mypack;
 2 import java.util.Set;
 3 import java.util.HashSet;
 4 import java.util.Iterator;
 5 
 6 public class Monkey{
 7 
 8 
 9     private Long id;
10     private String name;
11     private Set learnings=new HashSet();
12 
13     public Monkey(String name, Set learnings) {
14         this.name = name;
15         this.learnings = learnings;
16     }
17 
18     /** default constructor */
19     public Monkey() {
20     }
21 
22 
23     public Long getId() {
24         return this.id;
25     }
26 
27     public void setId(Long id) {
28         this.id = id;
29     }
30 
31     public String getName() {
32         return this.name;
33     }
34 
35     public void setName(String name) {
36         this.name = name;
37     }
38 
39     public Set getLearnings() {
40         return this.learnings;
41     }
42 
43     public void setLearnings(Set learnings) {
44         this.learnings = learnings;
45     }
46 
47  }

 

6.

 1 package mypack;
 2 
 3 import java.util.Set;
 4 import java.util.HashSet;
 5 
 6 public class Teacher{
 7     private Long id;
 8     private String name;
 9      private Set learnings=new HashSet();
10 
11     /** full constructor */
12     public Teacher(String name,Set learnings ) {
13         this.name = name;
14         this.learnings=learnings;
15     }
16 
17     /** default constructor */
18     public Teacher() {
19     }
20 
21     public String getName() {
22         return this.name;
23     }
24 
25     public void setName(String name) {
26         this.name = name;
27     }
28 
29     public Long getId() {
30         return this.id;
31     }
32 
33     public void setId(Long id) {
34         this.id = id;
35     }
36 
37     public Set getLearnings() {
38         return this.learnings;
39     }
40 
41     public void setLearnings(Set learnings) {
42         this.learnings = learnings;
43     }
44 
45 
46 }

 

7.

 1 package mypack;
 2 public class Learning{
 3     private Long id;
 4     private Teacher teacher;
 5     private Monkey monkey;
 6     private String gongfu;
 7     private int quantity;
 8 
 9     public Learning(Teacher teacher,Monkey monkey,String gongfu) {
10         this.teacher= teacher;
11         this.monkey = monkey;
12         this.gongfu=gongfu;
13     }
14 
15     /** default constructor */
16     public Learning() {
17     }
18     
19     public Long getId() {
20         return this.id;
21     }
22 
23     public void setId(Long id) {
24         this.id = id;
25     }
26 
27     public String getGongfu() {
28         return this.gongfu;
29     }
30 
31     public void setGongfu(String gongfu) {
32         this.gongfu = gongfu;
33     }
34 
35     public Monkey getMonkey() {
36         return this.monkey;
37     }
38 
39     public void setMonkey(Monkey monkey) {
40         this.monkey = monkey;
41     }
42 
43     public Teacher getTeacher() {
44         return this.teacher;
45     }
46 
47     public void setTeacher(Teacher teacher) {
48         this.teacher = teacher;
49     }
50     
51   }

 

8.

  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        Configuration config = new Configuration().configure();
 12        sessionFactory = config.buildSessionFactory();
 13     }catch(RuntimeException e){e.printStackTrace();throw e;}
 14   }
 15 
 16 
 17   public void saveMonkey(Monkey monkey){
 18     Session session = sessionFactory.openSession();
 19     Transaction tx = null;
 20     try {
 21       tx = session.beginTransaction();
 22       session.save(monkey);
 23       tx.commit();
 24 
 25     }catch (RuntimeException e) {
 26       if (tx != null) {
 27         tx.rollback();
 28       }
 29       throw e;
 30     } finally {
 31       session.close();
 32     }
 33   }
 34 
 35   public void saveTeacher(Teacher teacher){
 36     Session session = sessionFactory.openSession();
 37     Transaction tx = null;
 38     try {
 39       tx = session.beginTransaction();
 40       session.save(teacher);
 41       tx.commit();
 42 
 43     }catch (RuntimeException e) {
 44       if (tx != null) {
 45         tx.rollback();
 46       }
 47       throw e;
 48     } finally {
 49       session.close();
 50     }
 51   }
 52  public Monkey loadMonkey(Long id){
 53     Session session = sessionFactory.openSession();
 54     Transaction tx = null;
 55     try {
 56       tx = session.beginTransaction();
 57       Monkey monkey=(Monkey)session.get(Monkey.class,id);
 58       Set learnings=monkey.getLearnings();
 59       Iterator it=learnings.iterator(); //初始化Learnings
 60       while(it.hasNext()){
 61         Learning learning=(Learning)it.next();
 62         Hibernate.initialize(learning.getTeacher()); //初始化Teacher
 63       }
 64       tx.commit();
 65       return monkey;
 66 
 67     }catch (RuntimeException e) {
 68       if (tx != null) {
 69         tx.rollback();
 70       }
 71       throw e;
 72     } finally {
 73       session.close();
 74     }
 75   }
 76 
 77   public void printMonkey(Monkey monkey){
 78     System.out.println("名字:"+monkey.getName());
 79  
 80     Set learnings=monkey.getLearnings();
 81     Iterator it=learnings.iterator();
 82     while(it.hasNext()){
 83       Learning learning=(Learning)it.next();
 84       System.out.println("-----------------------");
 85       System.out.println("老师:"+learning.getTeacher().getName());
 86       System.out.println("功夫:"+learning.getGongfu());
 87      }
 88 
 89   }
 90 
 91  public void test(){
 92 
 93       Teacher teacher1=new Teacher("二郎神",null);
 94       Teacher teacher2=new Teacher("红孩儿",null);
 95       saveTeacher(teacher1);
 96       saveTeacher(teacher2);
 97 
 98       Monkey monkey=new Monkey();
 99       monkey.setName("智多星");
100       Learning learning1=new Learning(teacher1,monkey,"七十三变");
101       Learning learning2=new Learning(teacher2,monkey,"三昧真火");
102       
103       monkey.getLearnings().add(learning1);
104       monkey.getLearnings().add(learning2);
105       saveMonkey(monkey);
106 
107       monkey=loadMonkey(monkey.getId());
108       printMonkey(monkey);
109 
110   }
111 
112   public static void main(String args[]){
113     new BusinessService().test();
114     sessionFactory.close();
115   }
116 }

 

9.

 1 drop database if exists SAMPLEDB;
 2 create database SAMPLEDB;
 3 use SAMPLEDB;
 4 
 5 create table MONKEYS(
 6    ID bigint not null,
 7    NAME varchar(15),
 8    primary key (ID)
 9 );
10 
11 create table TEACHERS(
12   ID bigint not null,
13   NAME varchar(15),
14   primary key(ID)
15 );
16 
17 create table LEARNING(
18   ID bigint not null,
19   MONKEY_ID bigint not null,
20   TEACHER_ID bigint not null,
21   GONGFU varchar(15),
22   primary key(ID)
23 );
24 
25 alter table LEARNING add index IDX_MONKEY(MONKEY_ID), 
26 add constraint FK_MONKEY foreign key (MONKEY_ID) references MONKEYS(ID);
27 
28 alter table LEARNING add index IDX_TEACHER(TEACHER_ID), 
29 add constraint FK_TEACHER foreign key (TEACHER_ID) references TEACHERS(ID);

 

10.

 

posted @ 2016-03-20 22:33  shamgod  阅读(163)  评论(0)  编辑  收藏  举报
haha