数据源+freemarker+servlet生成xml文件

一.步骤:

1.在server.xml文件中建立数据源.

<Service name="Cms">
     <Connector debug="0" enableLookups="false" port="8084" protocol="AJP/1.3" redirectPort="8443"/>
    <Connector acceptCount="100" connectionTimeout="20000" debug="0" disableUploadTimeout="true" 

enableLookups="false" maxSpareThreads="75" maxThreads="150" minSpareThreads="25" port="8081" redirectPort="8443"/>
    <Engine defaultHost="localhost_Cms" name="Catalina_Cms">
      <Logger className="org.apache.catalina.logger.FileLogger" prefix="localhost_cmt_log." suffix=".txt" timestamp="true"/>
      <Realm className="org.apache.catalina.realm.UserDatabaseRealm"/>
      <Host autoDeploy="true" debug="0" name="localhost_Cms" unpackWARs="true" xmlNamespaceAware="false" xmlValidation="false">
         <Context debug="0" docBase="D:WorkspaceCMSweb" path="/" reloadable="true" workDir="D:WorkspaceCMSj2src"> 
          <Resource name="jdbc/news_DB" auth="Container" type="javax.sql.DataSource"/>
        <ResourceParams name="jdbc/news_DB">
     <parameter>
       <name>factory</name>
       <!-- DBCP Basic Datasource Factory -->
       <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
     </parameter>
      
     <parameter>
       <name>maxActive</name>
       <value>1000</value>
     </parameter>
     <parameter>
        <name>validationQuery</name>
        <value>select 1+1</value>
     </parameter>
     <parameter>
       <name>maxIdle</name>
       <value>100</value>
     </parameter>
     <parameter>
       <name>maxWait</name>
       <value>10000</value>
     </parameter>
     <parameter>
       <name>removeAbandoned</name>
       <value>true</value>
     </parameter>
     <parameter>
       <name>removeAbandonedTimeout</name>
       <value>60</value>
     </parameter>
     <parameter>
       <name>logAbandoned</name>
       <value>false</value>
     </parameter>
      
     <parameter>
       <name>username</name>
       <value>aaaa</value>
     </parameter>
     <parameter>
       <name>password</name>
       <value>bbbbbb</value>
     </parameter>
     <parameter>
       <name>driverClassName</name>
       <value>net.sourceforge.jtds.jdbc.Driver</value>
     </parameter>
     <parameter>
       <name>url</name>
       <value>jdbc:jtds:sqlserver://111.111.111.111:1433/cms</value>
     </parameter>
      </ResourceParams>
      
   </Context>
      </Host>
</Engine>
  </Service> 

2.在web.xml文件中配置servlet 

    <servlet>
        <description>generate xml file</description>
        <servlet-name>NewsXmlServlet</servlet-name>
        <servlet-class>xml.NewsXmlServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>NewsXmlServlet</servlet-name>
        <url-pattern>/xmlServlet</url-pattern>
    </servlet-mapping>
    <servlet>

3.newsXmlServlet.java

package xml;

import java.io.*;
import java.nio.charset.Charset;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

import freemarker.template.Configuration;
import freemarker.template.Template;
import freemarker.template.TemplateException;

import java.util.Locale;

public class NewsXmlServlet extends HttpServlet...{

    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException ...{
        // TODO Auto-generated method stub
        try ...{
            Connection conn=null;
            Context ctx = new InitialContext();
            DataSource ds=(DataSource)ctx.lookup("java:comp/env/jdbc/news_DB");
            conn=ds.getConnection();
            Statement stmt=conn.createStatement();
            ResultSet rs=stmt.executeQuery("select url,updatetime,tpf_edu_contentTitle,tpf_edu_contentneirong,tpf_edu_contentlaiyuan,tpf_edu_contentkeyword from tp5__edu_content where url<>'' and url is not null and dateDiff(d,updatetime,getDate())=1 order by updatetime desc");
            Configuration cfg=new Configuration();
            cfg.setDirectoryForTemplateLoading(new File("E:/wwwroot/CMS/web/WEB-INF/classes/xml"));
            Template tem=cfg.getTemplate("news.ftl");
            
            List list=new ArrayList();
            OutputStreamWriter out=new OutputStreamWriter(System.out);
            while(rs.next())...{
                Map item=new HashMap();
                item.put("title",rs.getString(3));
                item.put("link","http://test.com.cn"+rs.getString(1));
                item.put("pubdate",rs.getTimestamp(2));
                item.put("content",DelHtml(rs.getString(4)));
                item.put("source",rs.getString(5));
                item.put("keywords",DelHtml(rs.getString(6)));
                list.add(item);
            }
            Map data=new HashMap();
            data.put("items",list);
            StringWriter writer=new StringWriter();
            tem.process(data,writer);
            String content=writer.toString();
            writer.close();
            createXml(content);
            out.close();
            //resp.setContentType("text/xml; charset=utf-8");
            //resp.getWriter().write(content);
            
        } catch (NamingException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (TemplateException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
    public String DelHtml(String content)...{
        String contents=content.replaceAll("<\/?\s*(\S+)(\s*[^>]*)?\s*\/?>","");
         contents=contents.replaceAll("&ldquo;", "”");
  &n