http://heweiya.iteye.com/blog/106096

仔细看看hibernate的DOC发现不少惊奇的东东,后悔自己的旁门助道是多么的无用.
     本次主要实现目的.
     数据库表:EchoMessageEmail,其中有三个字段id(自动编号)\name\Email(varchar)
     实现目的:数据库字段中Email的值是类似于[email protected];[email protected];www.1718zx.cn的.所以要求以List表达.
也就是生成的DataModel当中是有一个List对象的.
     .hbm.xml

xml 代码

<?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>  
    <class name="com.travelsky.hibernate.po.EchoMessageEmail" table="echo_message_email">  
        <id name="id" type="java.lang.Integer">  
            <column name="ID" />  
            <generator class="native"></generator>  
        </id>  
        <property name="name" type="java.lang.String">  
            <column name="NAME" length="50" not-null="true" />  
        </property>  
        <property name="email" type="com.travelsky.hibernate.po.EmailList" lazy="true">  
            <column name="EMAIL"/>             
        </property>          
    </class>  
</hibernate-mapping>  
对应的POJO:

java 代码

package com.travelsky.hibernate.po;  
import java.util.List;  
  
/** 
* EchoMessageEmail generated by MyEclipse Persistence Tools 
*/  
  
public class EchoMessageEmail  implements java.io.Serializable {  
  
     private Integer id;  
     private String name;  
     private List email;  
  
    /** default constructor */  
    public EchoMessageEmail() {  
    }  
  
    /** minimal constructor */  
    public EchoMessageEmail(String name) {  
        this.name = name;  
    }  
      
    /** full constructor */  
    public EchoMessageEmail(String name, List email) {  
        this.name = name;  
        this.email = email;  
    }  
  
     
    // Property accessors  
  
    public Integer getId() {  
        return this.id;  
    }  
      
    public void setId(Integer id) {  
        this.id = id;  
    }  
  
    public String getName() {  
        return this.name;  
    }  
      
    public void setName(String name) {  
        this.name = name;  
    }  
  
    public List getEmail() {  
        return email;  
    }  
  
    public void setEmail(List email) {  
        this.email = email;  
    }  
  
}  
其中的UserType的一个类:EmailList

java 代码

package com.travelsky.hibernate.po;  
  
import java.io.Serializable;  
import java.sql.PreparedStatement;  
import java.sql.ResultSet;  
import java.sql.SQLException;  
import java.sql.Types;  
import java.util.ArrayList;  
import java.util.List;  
  
import org.apache.commons.lang.StringUtils;  
import org.hibernate.HibernateException;  
import org.hibernate.Hibernate;  
  
/** 
* 必须得引用java.io.Serializable,UserType是反序列化 
* 另外，我使用的hibernate版本是3.2，UserType从2.0到3.2有很大的差异，应该多多看看官方的doc 
*  
* @author @家军.严重注意org.hibernate.usertype.UserType,不要自己造车呀.
*  
*/  
public class EmailList implements java.io.Serializable,org.hibernate.usertype.UserType{  
  
    private List emails;  
  
    private static final String SPLITTER = ";";  
  
    private static final int[] TYPES = new int[] { Types.VARCHAR };  
  
    public int[] sqlTypes() {  
          
        return TYPES;  
    }  
  
    public Class returnedClass() {  
        // TODO Auto-generated method stub  
        return List.class;  
    }  
  
    public boolean equals(Object x, Object y) throws HibernateException {  
        if (x == y)  
            return true;  
        if (x != null && y != null) {  
            List xList = (List) x;  
            List yList = (List) y;  
            if (xList.size() != yList.size())  
                return false;  
            for (int i = 0; i < xList.size(); i++) {  
                String str1 = (String) xList.get(i);  
                String str2 = (String) yList.get(i);  
                if (!str1.equals(str2))  
                    return false;  
            }  
            return true;  
        }  
        return false;  
    }  
  
    public Object nullSafeGet(ResultSet rs, String[] names, Object owner)  
            throws HibernateException, SQLException {  
        String value = (String) Hibernate.STRING.nullSafeGet(rs, names[0]);  
        if (value != null) {  
            return parse(value);  
        } else {  
            return null;  
        }  
    }  
  
    public void nullSafeSet(PreparedStatement st, Object value, int index)  
            throws HibernateException, SQLException {  
        System.out.println("Set method excecuted");  
        if (value != null) {  
            String str = assemble((List) value);  
            Hibernate.STRING.nullSafeSet(st, str, index);  
        } else {  
            Hibernate.STRING.nullSafeSet(st, value, index);  
        }  
  
    }  
  
    public Object deepCopy(Object value) throws HibernateException {  
        List sourcelist = (List) value;  
        List targetlist = new ArrayList();  
        targetlist.addAll(sourcelist);  
        return targetlist;  
    }  
  
    public boolean isMutable() {          
        return false;  
    }  
  
    private String assemble(List emailList) {  
        StringBuffer strBuf = new StringBuffer();  
        for (int i = 0; i < emailList.size() - 1; i++) {  
            strBuf.append(emailList.get(i)).append(SPLITTER);  
        }  
        strBuf.append(emailList.get(emailList.size() - 1));  
        return strBuf.toString();  
    }  
  
    private List parse(String value) {  
        String[] strs = StringUtils.split(value, SPLITTER);  
        List emailList = new ArrayList();  
        for (int i = 0; i < strs.length; i++) {  
            emailList.add(strs[i]);  
        }  
        return emailList;  
    }  
  
    public Object assemble(Serializable arg0, Object arg1) throws HibernateException {  
        // TODO Auto-generated method stub  
        return null;  
    }  
  
    public Serializable disassemble(Object arg0) throws HibernateException {  
        // TODO Auto-generated method stub  
        return null;  
    }  
  
    public int hashCode(Object arg0) throws HibernateException {  
        // TODO Auto-generated method stub  
        return 0;  
    }  
  
    public Object replace(Object arg0, Object arg1, Object arg2) throws HibernateException {  
        // TODO Auto-generated method stub  
        return null;  
    }  
  
}  
测试类:

java 代码

package com.travelsky.test;  
import java.util.List;  
import java.util.ListIterator;  
import com.travelsky.hibernate.po.EchoMessageEmail;  
import org.hibernate.Query;  
import org.hibernate.Session;  
import org.hibernate.SessionFactory;  
import org.hibernate.cfg.Configuration;  
  
public class HibernateTest {  
  
    public static void main(String[] args) throws Exception{          
        Configuration config = new Configuration().configure();  
        SessionFactory factory = config.buildSessionFactory();  
        Session session = factory.openSession();  
        Query query = session.createQuery("from EchoMessageEmail as a");  
        /** 
         * 理论上来说,这里不存在lazy加载,为了安全起见使用了Iterator 
         *  
         */  
        ListIterator iterator = query.list().listIterator();  
        EchoMessageEmail tt = (EchoMessageEmail) iterator.next();//只找第一个  
        List emails = tt.getEmail();              
        for (int i = 0; i < emails.size(); i++) {  
            String emailStr = (String)emails.get(i);  
            System.out.println(emailStr);  
        }         
        session.close();  
    }