Hibernate的复合主键,基于主键类的复合主键

java 代码

public class User  implements java.io.Serializable {


    // Fields

     private UserId id;
     private String email;


    // Constructors

    /** default constructor */
    public User() {
    }


    /** full constructor */
    public User(String email) {
        this.email = email;
    }


    // Property accessors

    public UserId getId() {
        return this.id;
    }

    public void setId(UserId id) {
        this.id = id;
    }

    public String getEmail() {
        return this.email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

}

 

java 代码

public class UserId  implements java.io.Serializable {


    // Fields

     private String addr;
     private String name;


    // Constructors

    /** default constructor */
    public UserId() {
    }


    /** full constructor */
    public UserId(String addr, String name) {
        this.addr = addr;
        this.name = name;
    }


    // Property accessors

    public String getAddr() {
        return this.addr;
    }

    public void setAddr(String addr) {
        this.addr = addr;
    }

    public String getName() {
        return this.name;
    }

    public void setName(String name) {
        this.name = name;
    }




   public boolean equals(Object other) {
         if ( (this == other ) ) return true;
         if ( (other == null ) ) return false;
         if ( !(other instanceof UserId) ) return false;
         UserId castOther = ( UserId ) other;

         return ( (this.getAddr()==castOther.getAddr()) || ( this.getAddr()!=null && castOther.getAddr()!=null && this.getAddr().equals(castOther.getAddr()) ) )
 && ( (this.getName()==castOther.getName()) || ( this.getName()!=null && castOther.getName()!=null && this.getName().equals(castOther.getName()) ) );
   }

   public int hashCode() {
         int result = 17;

         result = 37 * result + ( getAddr() == null ? 0 : this.getAddr().hashCode() );
         result = 37 * result + ( getName() == null ? 0 : this.getName().hashCode() );
         return result;
   }

}

 

xml 代码

<hibernate-mapping>
    <class name="User" table="user" catalog="tie">
        <composite-id name="id" class="UserId">
            <key-property name="addr" type="string">
                <column name="addr" length="45" />
            key-property>
            <key-property name="name" type="string">
                <column name="name" length="45" />
            key-property>
        composite-id>
        <property name="email" type="string">
            <column name="email" length="45" />
        property>
    class>
hibernate-mapping>

 

这里把主键当成一个类,--->主键类.

有2点.

1,必须实现serializable

2.重写equals方法和hascode方法

xml中用compodite-id

测试的方法

java 代码

public void testCase(){
        UserId id = new UserId();
        id.setName("linwei");
        id.setAddr("beijing");
        User user = new User();
        user.setId(id);
        user.setEmail("[email protected]");

        Session session = factory.openSession();
        Transaction tr = session.beginTransaction();
        session.save(user);
        tr.commit();
        session.close();
    }

    public void testRetrieve(){

        UserId id = new UserId();
        id.setName("linwei");
        id.setAddr("beijing");

        Session session = factory.openSession();
        User user = (User)session.get(User.class, id);
        System.out.println(user.getEmail());
        session.close();
    }