activation-1.1ea.jar
antlr-2.7.5H3.jar
jnlp.jar
echopointng-2.0a5.jar
bsf-2.3.0.jar
bsh-2.0b2.jar
castor-0.9.6.jar
cglib-2.1.jar
commons-beanutils-1.7.0.jar
commons-collections-2.1.1.jar
commons-dbcp-1.2.1.jar
commons-digester-1.7.jar
commons-discovery-0.2.jar
commons-fileupload-1.0.jar
commons-lang-2.0.jar
commons-logging-1.0.4.jar
commons-pool-1.2.jar
dbunit-2.1.jar
dom4j-1.6.jar
drools-all-jdk5-2.1.jar
easymock-1.1.jar
easymockclassextension-1.1.jar
Echo2_WebRender.jar
jcommon-1.0.0.jar
jdt-compiler-3.1.1.jar
xml-apis.jar
Echo2_WebContainer.jar
Echo2_App.jar
ehcache-1.1.jar
groovy-all-1.0-beta-8.jar
hibernate-3.jar
hibernate-tools-2.1.3.jar
hsqldb-1.7.3.3.jar
itext-1.3.1.jar
janino-2.3.8.jar
jasper-compiler-5.0.8.jar
jasper-runtime-5.0.8.jar
jaxen-1.1-beta-4.jar
jaxrpc-1.1.jar
jep-2.3.0.jar
jetty-5.1.3.jar
jfreechart-0.9.8.jar
jgraph-5.7.3.jar
jsp-api-2.0.jar
jsr94-1.1.jar
jta-1.0.1B.jar
junit-3.8.1.jar
log4j-1.2.8.jar
mail-1.3.jar
mysql-connector-java-3.1.11-bin.jar
odmg-3.0.jar
poi-2.0-final-20040126.jar
quartz-1.5.1.jar
saaj-1.1.jar
servlet-api-2.4.jar
spring-1.2.5.jar
velocity-1.4.jar
wsdl4j-1.5.1.jar
xdoclet-1.2.1.jar
xdoclet-hibernate-module-1.2.1.jar
xdoclet-xdoclet-module-1.2.1.jar
xercesImpl-2.6.2.jar
xjavadoc-1.0.3.jar
axis-1.1.jar
Echo2_FileTransfer_App.jar
Echo2_FileTransfer_WebContainer.jar
jfreechart-1.0.0.jar
jasperreports-1.2.0.jar
上面是我们目前项目引用到jar包，当然都是open source的，涉及方面非常多，而且肯定还要增加。这一年多大多数时间就是和这68个包打交道，本着不发明轮子的观点，我们引入了一个又一个的开源包，这一年多来我所熟练的也就是如何在几个类似的框架中选择一个，查看tutorial，翻api，将其集成到我们的框架中来。遇到问题，mail list，论坛，源代码基本上也都可以解决。但是其核心如何实现，该怎样实现却一无所知，越来越觉得做的事情毫无技术含量。
抱怨归抱怨，因为时间，人手和能力的限制，我们也不可能去重复地发明轮子。造一个自己的轮子，感觉一定很好。

最后介绍一下使用Hibernate的方式，由于我们项目持久层本来就是使用Hibernate，这种方式应该说是最好的方案了。Hibernate 3开始提供了一种将pojo直接映射为xml文件的能力，并可以进行读入。一段简单的导出导入的代码：

/*
 * rst project
 *
 * Created on 2005-8-16
 */

package rst.framework.init;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
import org.hibernate.cfg.Configuration;

import org.hibernate.EntityMode;
import org.hibernate.ReplicationMode;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;

/**
 * @author rst
 *
 * Class description.
 */
public class HibernateToXml {
    private static void createDocument() {
        Session session;
        session = getSession();
        Session s = session.getSession(EntityMode.DOM4J);

        Document doc = DocumentHelper.createDocument();
        Element root = doc.addElement("root");

        List results = s.createQuery("PchsOrder").list();
        addResultsToNode(results, root);

        OutputFormat format = OutputFormat.createPrettyPrint();
        try{
            XMLWriter writer = new XMLWriter(new FileWriter("content.xml"), format);
            writer.write(doc);
            writer.close();
        }catch(IOException ioe) {
        }

    }

    public static void readDocument(){
        try{
            SAXReader reader = new SAXReader();
            Document doc = reader.read(new File("content.xml"));

            Session session = getSession();
            Session s = session.getSession(EntityMode.DOM4J);
            Transaction txn = s.beginTransaction();
                     
            List elems = doc.getRootElement().elements();
            Iterator it = elems.iterator();
            while(it.hasNext()){
                Element e = (Element)it.next();
                if(e.getName().equals("PchsOrder"))
                    s.replicate("PchsOrder", e, ReplicationMode.IGNORE);                
            }

            txn.commit();
            session.close();
           
        }catch(DocumentException e){
        }
    }
   
    private static void addResultsToNode(List results, Element root){
        for (Iterator i = results.iterator(); i.hasNext();) {
            Element e = (Element) i.next();
            e.setName("PchsOrder");
            if(e != null){
                root.add(e);
            }
        }
    }
   
    private static Session getSession(){

        Configuration configuration = new Configuration();
        configuration.configure();
        SessionFactory sessionFactory = configuration.buildSessionFactory();
        return sessionFactory.openSession();
    }

    public static void main(String[] args){
        //createDocument();
        readDocument();
    }
}

导出后的文件如下：
<?xml version="1.0" encoding="UTF-8"?>

<root>
  <PchsOrder id="4028803c04ff25910104ff272432000b">
    <code>001</code>
    <items>
      <PchsOrderItem id="4028803c04ff25910104ff272450000c">
        <estimatedDeliveryDate>2005-07-10 13:09:53</estimatedDeliveryDate>
        <itemDescriptions>For business</itemDescriptions>
        <PchsOrder Id="4028803c04ff25910104ff272432000b"/>
        <Products id="001">
          <code>001</code>
          <introductionDate>2010-12-31 00:00:00</introductionDate>
          <name>IBM Tinkpad R32</name>
          <salesDiscontinuationDate>2022-12-31 00:00:00</salesDiscontinuationDate>
          <supportDiscontinuationDate>2030-12-31 00:00:00</supportDiscontinuationDate>
        </Products>
        <quantity>20.000000000000000000000000000000</quantity>
        <seqId>1</seqId>
        <unitPrice>99.999999999999999999999999999999</unitPrice>
      </PchsOrderItem>
      <PchsOrderItem id="4028803c04ff25910104ff272450000d">
        <estimatedDeliveryDate>2005-07-10 13:10:25</estimatedDeliveryDate>
        <itemDescriptions>For business</itemDescriptions>
        <PchsOrder Id="4028803c04ff25910104ff272432000b"/>
        <Products id="002">
          <code>002</code>
          <introductionDate>2015-12-31 00:00:00</introductionDate>
          <name>IBM Thinkpad T42</name>
          <salesDiscontinuationDate>2030-12-31 00:00:00</salesDiscontinuationDate>
          <supportDiscontinuationDate>2040-12-31 00:00:00</supportDiscontinuationDate>
        </Products>
        <quantity>40.000000000000000000000000000000</quantity>
        <seqId>2</seqId>
        <unitPrice>99.999999999999999999999999999999</unitPrice>
      </PchsOrderItem>
      <PchsOrderItem id="402880e905aee8970105aee976640017">
        <estimatedDeliveryDate>2005-08-13 16:16:27</estimatedDeliveryDate>
        <itemDescriptions>asdfasdf</itemDescriptions>
        <PchsOrder Id="4028803c04ff25910104ff272432000b"/>
        <Products id="001">
          <code>001</code>
          <introductionDate>2010-12-31 00:00:00</introductionDate>
          <name>IBM Tinkpad R32</name>
          <salesDiscontinuationDate>2022-12-31 00:00:00</salesDiscontinuationDate>
          <supportDiscontinuationDate>2030-12-31 00:00:00</supportDiscontinuationDate>
        </Products>
        <quantity>99.999999999999999999999999999999</quantity>
        <seqId>3</seqId>
        <unitPrice>99.999999999999999999999999999999</unitPrice>
      </PchsOrderItem>
    </items>
    <orderDate>2005-07-10 13:09:27</orderDate>
    <supplier>IBM Corp.</supplier>
    <status>N</status>
  </PchsOrder>
</root>

介绍了3中导入导出数据的方式，如何选择就要看具体的场景了。Java领域越来越多的开源产品很多时候确实让人难以选择，要想选择最合适的就必须都试试看，just do it :)