Hibernate 实现复合主键的使用

转发自 https://blog.csdn.net/guominjin/article/details/78963578

  1>:首先将要作为主键的属性首先抽取成单独的实体  并提供get And set方法  并且还需要序列化

      比如现在有一个实体 People ,具有属性pName,pAddress,pJavaScore,pCscore

     复合主键为pName,pAddress

   **********将这两个属性抽离形成一个新的实体并提供setter,gettter方法实现序列化（坑区）

compositionkey.java

 

  

   

    

   
   

    

     import java.io.Serializable;
    
   
  

   

    

   
   

    
 
    
   
  

   

    

   
   

    

     /**
    
   
  

   

    

   
   

    

      * 
    
   
  

   

    

   
   

    

      * @author Guomin JIn
    
   
  

   

    

   
   

    

      *
    
   
  

   

    

   
   

    

      */
    
   
  

   

    

   
   

    

     public 
     class CompositionKey implements Serializable{
    
   
  

   

    

   
   

    
 
     private String pName;
    
   
  

   

    

   
   

    
 
     private String pAddress;
    
   
  

   

    

   
   

    
 
     public String getpName() {
    
   
  

   

    

   
   

    
 
     return pName;
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
     public void setpName(String pName) {
    
   
  

   

    

   
   

    
 
     this.pName = pName;
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
     public String getpAddress() {
    
   
  

   

    

   
   

    
 
     return pAddress;
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
     public void setpAddress(String pAddress) {
    
   
  

   

    

   
   

    
 
     this.pAddress = pAddress;
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
    
   
  

   

    

   
   

    

     }
    
   
 
 

抽离之后的Peopel实体如下:

People.java

 

  

   

    

   
   

    

     package cn.pzhu.composition;
    
   
  

   

    

   
   

    

     /**
    
   
  

   

    

   
   

    

      * 实体类
    
   
  

   

    

   
   

    

      * @author Guomin JIn
    
   
  

   

    

   
   

    

      *
    
   
  

   

    

   
   

    

      */
    
   
  

   

    

   
   

    

     public 
     class People {
    
   
  

   

    

   
   

    
 
     private CompositionKey key;
    
   
  

   

    

   
   

    
 
     private 
     float pJavaScore;
    
   
  

   

    

   
   

    
 
     private 
     float pCScore;
    
   
  

   

    

   
   

    
 
     public CompositionKey getKey() {
    
   
  

   

    

   
   

    
 
     return key;
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
     public void setKey(CompositionKey key) {
    
   
  

   

    

   
   

    
 
     this.key = key;
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
     public float getpJavaScore() {
    
   
  

   

    

   
   

    
 
     return pJavaScore;
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
     public void setpJavaScore(float pJavaScore) {
    
   
  

   

    

   
   

    
 
     this.pJavaScore = pJavaScore;
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
     public float getpCScore() {
    
   
  

   

    

   
   

    
 
     return pCScore;
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
     public void setpCScore(float pCScore) {
    
   
  

   

    

   
   

    
 
     this.pCScore = pCScore;
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
     @Override
    
   
  

   

    

   
   

    
 
     public String toString() {
    
   
  

   

    

   
   

    
 
     return 
     "People [key=" + key + 
     ", pJavaScore=" + pJavaScore + 
     ", pCScore=" + pCScore + 
     "]";
    
   
  

   

    

   
   

    

      }
    
   
  

   

    

   
   

    
 
    
   
  

   

    

   
   

    
 
    
   
  

   

    

   
   

    

     }
    
   
 
 

  3>:在映射文件中编写实体的配置文件

配置文件如下：

hibernate.cfg.xml省略()

people.hbm.xml

 

  

   

    

   
   

    

     <?xml version="1.0"?>
    
   
  

   

    

   
   

    

     <!DOCTYPE hibernate-mapping PUBLIC
    
   
  

   

    

   
   

    

      "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    
   
  

   

    

   
   

    

      "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    
   
  

   

    

   
   

    
 
    
   
  

   

    

   
   

    

     <hibernate-mapping package="cn.pzhu.composition">
    
   
  

   

    

   
   

    
 
     <class name="People" table="peopel" >
    
   
  

   

    

   
   

    
 
     <composite-id name="key">
    
   
  

   

    

   
   

    
 
     <key-property name="pName" length="10" type="java.lang.String">
     </key-property>
    
   
  

   

    

   
   

    
 
     <key-property name="pAddress" length="10" type="java.lang.String">
     </key-property>
    
   
  

   

    

   
   

    
 
     </composite-id>
    
   
  

   

    

   
   

    
 
     <property name="pJavaScore" length="5"/>
    
   
  

   

    

   
   

    
 
     <property name="pCScore">
     </property>
    
   
  

   

    

   
   

    
 
     </class>
    
   
  

   

    

   
   

    

     </hibernate-mapping>
    
   
 
 

测试类使用junit

 

  

   

    

   
   

    

     @Test
    
   
  

   

    

   
   

    
 
     public void test_0001() {
    
   
  

   

    

   
   

    

      Session session=
     new Configuration()
    
   
  

   

    

   
   

    

      .configure(
     "hibernate.cfg.xml")
    
   
  

   

    

   
   

    

      .addClass(People.class)
    
   
  

   

    

   
   

    

      .buildSessionFactory()
    
   
  

   

    

   
   

    

      .openSession();
    
   
  

   

    

   
   

    
 
    
   
  

   

    

   
   

    

      session.beginTransaction();
    
   
  

   

    

   
   

    
 
    
   
  

   

    

   
   

    

      CompositionKey key=
     new CompositionKey();
    
   
  

   

    

   
   

    

      key.setpName(
     "jgm");
    
   
  

   

    

   
   

    

      key.setpAddress(
     "chengdu");
    
   
  

   

    

   
   

    
 
    
   
  

   

    

   
   

    

      People people=
     new People();
    
   
  

   

    

   
   

    

      people.setKey(key);
    
   
  

   

    

   
   

    

      people.setpJavaScore(
     12.34f);
    
   
  

   

    

   
   

    

      people.setpCScore(
     36.2f);
    
   
  

   

    

   
   

    
 
     //HibernateUtil.save(people);
    
   
  

   

    

   
   

    

      session.save(people);
    
   
  

   

    

   
   

    

      }