hibernate3.2上使用UserType范例

     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();
    }
}