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;
}