JAVA_读取数据库数据并打成ZIP包下载

当时需求：读取ORCLE大字段数据，并根据需求将三个大字段的内容分别保存为xml/html文件，并打包下载

package com.comtop.product.taskform.catalogmanagement.action;

import javax.servlet.http.HttpServlet;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipOutputStream;

import com.comtop.util.Toolkit;
import com.comtop.eaiform.TemplateInfo;
import com.comtop.product.taskform.delegate.TemplateMan;


/**
 * 作业表单ZIP包下载servlet
 * @author  周波
 * @since   JDK1.4
 * @History 2011年9月2日15:35:49 周波 新建
 */
public class DownTaskFormTemplate extends HttpServlet{

    /** 日志对象*/
    private final Logger logger = Toolkit.getLogger(this.getClass().getName());

    public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{
         downloadTaskFrom(request, response);
    }


    public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{

    }

    /*
     *下载作业表单ZIP包
     *
     * */
    public void downloadTaskFrom(HttpServletRequest request, HttpServletResponse
            response)throws ServletException, IOException{

        //模板版本ID
        String template_version_id = request.getParameter("template_version_id");
        //ZIP包名
        String tempalteName = request.getParameter("template_Name");

        ZipOutputStream zipOut = null;
        InputStream ins = null;


        try {
            response.reset();
            //下载zip文件名
            String strZipFileName = tempalteName+".zip";
            //得到输出流
            response.setHeader("Content-Disposition:",
                    "attachment;filename=" +new String(strZipFileName.getBytes("gb2312"), "ISO8859_1"));

            String path = this.getServletContext().getRealPath("");
            StringBuffer sbPath = new StringBuffer(path);
            sbPath.append("/temp/");
            //2011-5-10 确认是否存在temp文件夹，若不存在则先创建
            this.checkAndCreatePacakage(sbPath.toString());
            sbPath.append(strZipFileName);
            FileOutputStream objFileOutputStream=new FileOutputStream(new File(sbPath.toString()));
            zipOut = new ZipOutputStream(objFileOutputStream);
            TemplateMan objTemplateMan=new TemplateMan();

            String[] files=objTemplateMan.getReportFile(template_version_id);
            //写入XML存储格式
            if(files[0]!=null){
                writeXmlFile(zipOut,files[0],tempalteName+"存储格式.xml");
            }
            //写入XML模板内容
            if(files[1]!=null){
                writeXmlFile(zipOut,files[1],tempalteName+"模板内容.xml");
            }
            //写入HTML内容
            if(files[2]!=null){
                writeXmlFile(zipOut, files[2],tempalteName+"HTML内容.html");
            }
            //下载标准模板
           // newDownStandarTemplate(packageId,zipOut);

            //关闭ZIP流
            if (zipOut != null) {
                zipOut.close();
            }
            writeOutStream(sbPath.toString(),response);
        }catch (Exception e) {
            logger.error("action.DownTaskFormTemplate.下载作业表单ZIP包出错！",e);
         }

    }

    private void writeXmlFile(ZipOutputStream zipOut,String file,String filwName){
        try{
            zipOut.putNextEntry(new ZipEntry(filwName));
            //转换为ZIP文件
            zipOut.write(file.getBytes("UTF-8"), 0, file.getBytes("UTF-8").length);
            // 关闭ZIP输出流
            zipOut.closeEntry();
        }catch(Exception e){
            logger.error("文件写入异常",e);
        }
    }

    /**
     * 2011-09-02 周波 创建 确认是否存在文件夹，若不存在则创建
     * @param filePath
     */
    private void checkAndCreatePacakage(String filePath){
        File objFile = new File(filePath);
        if(!objFile.isDirectory()){
            objFile.mkdirs();
        }
    }

    //输出流
    private void writeOutStream(String fileName,HttpServletResponse response)throws ServletException, IOException{
        OutputStream out = response.getOutputStream();
        File objFile=new File(fileName);
        FileInputStream objFileInputStream=new FileInputStream(objFile);
        //定义缓存输入流
        BufferedInputStream objBufferedInputStream = new BufferedInputStream(objFileInputStream);
        //缓存区
        byte[] buffer = new byte[5000];
        while (true) {
            // 读入缓存输入流
            int bytesRead = objFileInputStream.read(buffer, 0, buffer.length);
            if (bytesRead < 0) {
                break;
            }
            // 写入输出流
            out.write(buffer, 0, bytesRead);
        }
        // 关闭缓存输入流
        objBufferedInputStream.close();

        // 关闭文件输入流
        objFileInputStream.close();
        // 刷新和关闭输出流
        out.flush();
        out.close();
        //将临时文件删除
        objFile.delete();
    }
}