Hibernate实现one-to-one级联保存[自己总结]

http://www.blogjava.net/1504/admin/EditPosts.aspx?opt=1

在具体的项目应用中,我们很少会用到一对一的级联操作,且很多时候一对一的操作可以通过多对一实现,但是一对一有自己的好处,就是在任何时候都能保证主外键数据的一致性,但是多对一的情况下未必能做到.
我在项目中具体用到了一对一的级联操作,从网上拿了一个例子来做,但是没有成功,于是只好自己研究,现在把修改后的代码帖出来.
本例子使用hibernate3.jar+oracle数据库
库表:
CARD_TEST(CARDID[NUMBER(18)],CARDNUM[VARCHAR2(20)])
USER_TEST(USERID[NUMBER(18)],USERNAME[VARCHAR2(20)])
TestMain.java

package com.gpdi.test;
import org.hibernate.Session;
import org.hibernate.Transaction;
public class TestMain {
/**
* 存储一个用户
* @param user
*/
public void save(User user){
user.setUsername("TEST");
Card card=new Card();
//Card card1=new Card();
card.setCardnum("HGJUYT");
//card1.setCardnum("fghy55");
user.setCard(card);
//user.setCard(card1);
Session session=HibernateSessionFactory.currentSession();
card.setUser(user);
//card1.setUser(user);
Transaction tr=session.beginTransaction();
session.save(user);
//session.save(card);
tr.commit();
session.close();
}

public static void main(String[] args) throws Exception {
TestMain test=new TestMain();
test.save(new User());
}

}
Card.java

package com.gpdi.test;

/**
* Card generated by MyEclipse - Hibernate Tools
*/

public class Card implements java.io.Serializable {
// Fields

     private Integer cardid;
     private String cardnum;
     private User user;

// Constructors

    public User getUser() {
  return user;
}
public void setUser(User user) {
  this.user = user;
}
/** default constructor */
    public Card() {
    }
    /** full constructor */
    public Card(String cardnum) {
        this.cardnum = cardnum;
    }
    // Property accessors

    public Integer getCardid() {
        return this.cardid;
    }

    public void setCardid(Integer cardid) {
        this.cardid = cardid;
    }

    public String getCardnum() {
        return this.cardnum;
    }

    public void setCardnum(String cardnum) {
        this.cardnum = cardnum;
    }

}

User.java
package com.gpdi.test;

import java.util.HashSet;
import java.util.Set;

/**
* User generated by MyEclipse - Hibernate Tools
*/

public class User implements java.io.Serializable {
// Fields

     private Integer userid;
     private String username;
     private Card card;
     //private Set card = new HashSet();
    // Constructors

    public Card getCard() {
  return card;
}
public void setCard(Card card) {
  this.card = card;
}
/** default constructor */
    public User() {
    }
    /** full constructor */
    public User(String username) {
        this.username = username;
    }
    // Property accessors

    public Integer getUserid() {
        return this.userid;
    }

    public void setUserid(Integer userid) {
        this.userid = userid;
    }

    public String getUsername() {
        return this.username;
    }

    public void setUsername(String username) {
        this.username = username;
    }
}
HibernateSessionFactory.java

package com.gpdi.test;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;

/**
* Configures and provides access to Hibernate sessions, tied to the
* current thread of execution. Follows the Thread Local Session
* pattern, see {@link http://hibernate.org/42.html}.
*/
public class HibernateSessionFactory {

    /**
     * Location of hibernate.cfg.xml file.
     * NOTICE: Location should be on the classpath as Hibernate uses
     * #resourceAsStream style lookup for its configuration file. That
     * is place the config file in a Java package - the default location
     * is the default Java package.<br><br>
     * Examples: <br>
     * <code>CONFIG_FILE_LOCATION = "/hibernate.conf.xml".
     * CONFIG_FILE_LOCATION = "/com/foo/bar/myhiberstuff.conf.xml".</code>
     */
    private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";

/** Holds a single instance of Session */
private static final ThreadLocal threadLocal = new ThreadLocal();

/** The single instance of hibernate configuration */
private static final Configuration cfg = new Configuration();

/** The single instance of hibernate SessionFactory */
private static org.hibernate.SessionFactory sessionFactory;

    /**
     * Returns the ThreadLocal Session instance. Lazy initialize
     * the <code>SessionFactory</code> if needed.
     *
     * @return Session
     * @throws HibernateException
     */
    public static Session currentSession() throws HibernateException {
        Session session = (Session) threadLocal.get();

  if (session == null || !session.isOpen()) {
   if (sessionFactory == null) {
    try {
     cfg.configure(CONFIG_FILE_LOCATION);
     sessionFactory = cfg.buildSessionFactory();
    } catch (Exception e) {
     System.err
       .println("%%%% Error Creating SessionFactory %%%%");
     e.printStackTrace();
    }
   }
   session = (sessionFactory != null) ? sessionFactory.openSession()
     : null;
   threadLocal.set(session);
  }

return session;
}

    /**
     * Close the single hibernate session instance.
     *
     * @throws HibernateException
     */
    public static void closeSession() throws HibernateException {
        Session session = (Session) threadLocal.get();
        threadLocal.set(null);

        if (session != null) {
            session.close();
        }
    }

    /**
     * Default constructor.
     */
    private HibernateSessionFactory() {
    }

}
Card.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
    <class name="com.gpdi.test.Card" table="CARD_TEST">

        <id name="cardid" type="integer">
            <column name="CARDID" />
            <generator class="foreign" >
            <param name="property">user</param>
            </generator>
        </id>
        <property name="cardnum" type="string">
            <column name="CARDNUM" length="45" not-null="true" />
        </property>
        
       <one-to-one name="user" foreign-key="userid" class="com.gpdi.test.User" cascade="save-update"></one-to-one>
    </class>
</hibernate-mapping>

User.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
    <class name="com.gpdi.test.User" table="USER_TEST">
        <id name="userid" type="integer">
            <column name="USERID" />
            <generator class="increment"/>
        </id>
        <property name="username" type="string">
            <column name="username" length="45" not-null="true" />
        </property>
        <one-to-one name="card" foreign-key="cardid" class="com.gpdi.test.Card" cascade="save-update"></one-to-one>
        

    </class>
</hibernate-mapping>
http://www.blogjava.net/Files/1504/one-to--one.rar

Hibernate实现one-to-one级联保存[自己总结]

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