两种方式配置Hibernate复合主键(修正)

数据库结构

create table component(name varchar(50) not null,
                       sex varchar(50) not null,
                       description varchar(50),
                       primary key(name,sex));

主键类，一定要实现Serializable接口，并改写equals和hascode方法

package  component;

import  java.io.Serializable;

import  org.apache.commons.lang.builder.EqualsBuilder;
import  org.apache.commons.lang.builder.HashCodeBuilder;

public   class  ComponentPK  implements  Serializable  ... {
   private  String name;
   private  String sex;

public  String getName()  ... {
     return  name;
}
public   void  setName(String name)  ... {
     this .name  =  name;
}
public  String getSex()  ... {
     return  sex;
}
public   void  setSex(String sex)  ... {
     this .sex  =  sex;
}
public   boolean  equals(Object obj)  ... {
     if (obj  ==   this )  ... {
         return   true ;
    }
    
     if ( ! (obj  instanceof  Component))  ... {
         return   false ;
    }
    
    ComponentPK componentpk  =  (ComponentPK) obj;
     return   new  EqualsBuilder()
          .append( this .name, componentpk.getName())
          .append( this .sex, componentpk.getSex())
          .isEquals();
    
  }
  
   public   int  hashCode()  ... {
     return   new  HashCodeBuilder()
          .append( this .name)
          .append( this .sex)
          .toHashCode();
  }

}

package  component;

public   class  Component  ... {
   private  String description;
   private  ComponentPK componentpk;
public  ComponentPK getComponentpk()  ... {
     return  componentpk;
}
public   void  setComponentpk(ComponentPK componentpk)  ... {
     this .componentpk  =  componentpk;
}
public  String getDescription()  ... {
     return  description;
}
public   void  setDescription(String description)  ... {
     this .description  =  description;
}
}

HBM文件

<? xml version="1.0" encoding="utf-8" ?>
<! DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<!--  
    Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
< hibernate-mapping  package ="component" >  

   < class  name ="Component"  table ="component" >  
     < composite-id  name ="componentpk"
              class ="ComponentPK"
              unsaved-value ="any" >
         < key-property  name ="name"  
                column ="name"  
                type ="java.lang.String" />
         < key-property  name ="sex"  
                column ="sex"  
                type ="java.lang.String" />
     </ composite-id >
    
     < property  name ="description"  column ="description"  type ="java.lang.String" />
  
   </ class >  

</ hibernate-mapping >

测试代码：

public   static   void  main(String[] args)  ... {
        Configuration cfg = new  Configuration();
        cfg.configure();
        SessionFactory sf = cfg.buildSessionFactory();
        Session session = sf.openSession();
        Transaction t = session.beginTransaction();
        
        ComponentPK pk = new  ComponentPK();
        pk.setName( " 1 " );
        pk.setSex( " 3 " );
        
        Component component = new  Component();
        component.setComponentpk(pk);
        component.setDescription( " 12 " );
        session.save(component);
        t.commit();
        System.out.println( " success " );

    }

如果组成复合主键的某一个属性是其他持久话类的话，则需要使用<key many-to-one>

增加表User:

CREATE TABLE `user` (
  `id` varchar(50) NOT NULL,
  `pass` varchar(50) default NULL,
  PRIMARY KEY  (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=gb2312;  

增加持久化类User及相应的Mapping文件

package  component;

public   class  User  ... {
    private  String id;
    private  String pass;
public  String getId()  ... {
     return  id;
}
public   void  setId(String id)  ... {
     this .id  =  id;
}
public  String getPass()  ... {
     return  pass;
}
public   void  setPass(String pass)  ... {
     this .pass  =  pass;
}
}

<?xml version = " 1.0 "  encoding = " utf-8 " ?>
<!DOCTYPE hibernate-mapping PUBLIC  " -//Hibernate/Hibernate Mapping DTD 3.0//EN "
" http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd " >
<!-- 
    Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping package = " component " > 

  <class name = " User "  table = " user " > 
   
    <id name = " id "  column = " id " >
      <generator class = " assigned " ></generator>
    </id>
    <property name = " pass "  column = " pass "  type = " java.lang.String " />
  
  </class> 

</hibernate-mapping>

修改ComponentPK类

package  component;

import  java.io.Serializable;

import  org.apache.commons.lang.builder.EqualsBuilder;
import  org.apache.commons.lang.builder.HashCodeBuilder;

public   class  ComponentPK  implements  Serializable  ... {
   private  String name;
   private  String sex;
   private  User user;
public  User getUser()  ... {
     return  user;
}

两种方式配置Hibernate复合主键(修正)