java 压缩导出多个excel

简单介绍下我实现的功能,首先是我的excel上传，它是以blob字段存储在oracel数据库中的，我实现的是循环遍历blob字段并使用io流进行打包下载，如有需要可自行修改

使用技术有，springMVC，mabits , bootstrap

1.前台

这里给出主要代码块

<div class="row">
                <div class="col-md-12 ">
                    <a href="tab-trainer-info.htm?status=1" class="btn btn-danger" title='#springMessage("back")'>  <i class="glyphicon glyphicon-step-backward"></i></a>

                    <a href="downloadPreHomeWorkZIP.htm?sessionId=$!sessionId" class="btn  btn-info downloadPreZip" title='#springMessage("preWorkZip")'>   <i class="glyphicon glyphicon-download-alt"></i> #springMessage("preWorkZip")</a>

                    <a href="downloadAfterHomeWorkZIP.htm?sessionId=$!sessionId" class="btn  btn-info downloadAfterZip" title='#springMessage("afterWorkZip")'>   <i class="glyphicon glyphicon-download-alt"></i> #springMessage("afterWorkZip")</a>
             </div>
        </div>

注意这里点击按钮时用的超链接，不要用的ajax提交，ajax慎用，我自己一开始使用的ajax，最后无法下载，搞了半天，后来百度，说ajax下载无法调用浏览器的下载机制，如果有必要也可以使用（要用form封装，我这里不再具体介绍，有尝试的小伙伴，可以共享一下，哈哈）

2. Controller  读取数据

@RequestMapping(value = "downloadPreHomeWorkZIP")
    public void downloadLetterZIP(trainTraineeWorkModel query, HttpServletResponse response, HttpServletRequest request)
            throws IOException, SQLException {
        String serverPath = request.getSession().getServletContext().getRealPath("/") + "\\upload\\tempExcel";  //设置下载excel的临时文件夹
        List<File> srcfile = new ArrayList<File>();  //声明一个集合，用来存放多个Excel文件路径及名称
        // 得到路径下的文件，如果不存在创建文件夹
        File file = new File(serverPath);
        if (!file.exists()) {
            file.mkdir();
        }
        List<Map> employees = employeeService // 查询学员上传的课前课后作业 （这里根据自己的需要获取数据，写入流中）
                .getMapTraineesBySessionId(query.getSessionId());
        if (employees.size() != 0) {
            for (Map map : employees) {
                BLOB blob = (BLOB) map.get("BEFORECLASS_WORK");
                if (blob != null && blob.length() != 0) {
                    String employeeCode = (String) map.get("EMPLOYEE_CODE");
                    String filename = employeeCode + "_" + DateUtil.getExportDate();   //定义现在excel文件名称，注意这里不是压缩包的名称
                    ZipUtils.execute(serverPath +"\\"+ filename+ ".xls", blob);   //ZipUtils是我自己定义的一个工具类，因为用到的下载太多了，往下看
                    String encodedfileName = new String(filename.getBytes(), "UTF-8");
                    srcfile.add(new File(serverPath + "\\" + encodedfileName + ".xls"));  //存放到List集合中
                }
            }
            // 将服务器上存放Excel的文件夹打成zip包
            File zipfile = new File(serverPath+"\\" + "PreWork" + ".zip");
            ZipUtils.zipFiles(srcfile, zipfile);// 实现将多个excel打包成zip文件
            //下载
            ZipUtils.downFile(response, serverPath, "PreWork" + ".zip");  //实现将压缩包写入流中，下载到本地，并删除临时文件中的压缩包及文件

        }
}

3.使用工具类

这里是我第二步说的自己定义的工具类，我用的maven，需要导入一些Io流包

package common.util;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
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.net.URLEncoder;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import javax.servlet.http.HttpServletResponse;

import oracle.sql.BLOB;

public class ZipUtils {
    /**
     * 将多个Excel打包成zip文件
     * @param srcfile
     * @param zipfile
     */
    public static void zipFiles(List<File> srcfile, File zipfile) {
        byte[] buf = new byte[1024];
        try {
            // Create the ZIP file
            ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipfile));
            // Compress the files
            for (int i = 0; i < srcfile.size(); i++) {
                File file = srcfile.get(i);
                FileInputStream in = new FileInputStream(file);
                // Add ZIP entry to output stream.
                out.putNextEntry(new ZipEntry(file.getName()));
                // Transfer bytes from the file to the ZIP file
                int len;
                while ((len = in.read(buf)) > 0) {
                    out.write(buf, 0, len);
                }
                // Complete the entry
                out.closeEntry();
                in.close();
            }
            // Complete the ZIP file
            out.close();
        } catch (IOException e) {
           e.printStackTrace();
        }
    }
  //filename为单个excel的路径和excel的名称，blob就是获取的blob数据
    public static int execute(String filename, BLOB blob)
    {
      int success = 1;
      try
      {
        File              blobFile   = new File(filename);
        FileOutputStream  outStream  = new FileOutputStream(blobFile);
        InputStream       inStream   = blob.getBinaryStream();
        int     length  = -1;
        int     size    = blob.getBufferSize();
        byte[]  buffer  = new byte[size];
        while ((length = inStream.read(buffer)) != -1)
        {
          outStream.write(buffer, 0, length);
          outStream.flush();
        }
        inStream.close();
        outStream.close();
      }
      catch (Exception e)
      {
        e.printStackTrace();
        success = 0;
      }
      finally
      {
        return success;
      }

    }  

    /**
     * 删除目录下所有的文件;
     * @param path
     */
    public static boolean deleteExcelPath(File file){
        String[] files = null;
        if(file != null){
            files = file.list();
        }    

        if(file.isDirectory()){
            for(int i =0;i<files.length;i++){
                boolean bol = deleteExcelPath(new File(file,files[i]));
                if(bol){
                    System.out.println("删除成功!");
                }else{
                    System.out.println("删除失败!");
                }
            }
        }
        return file.delete();
    }   

    public static void downFile(HttpServletResponse response,String serverPath, String str) {
        //下面注释代码虽然少，但是慎用，如果使用，压缩包能下载，但是下载之后临时文件夹会被锁住被jvm占用，不能删除
//        response.setCharacterEncoding("utf-8");
//         try {
//             File file=new File(serverPath,str);
//             response.setHeader("Content-Disposition",
//                        "attachment; filename="+ StringUtil.encodingFileName(str));
//                response.setContentType("application/octet-stream; charset=utf-8");
//                InputStream in1 =new FileInputStream(file.getPath());
//                IOUtils.copy(in1, response.getOutputStream());
//
//          }
//          catch (IOException ex) {
//             ex.printStackTrace();
//         }

        try {
            String path = serverPath +"\\"+ str;
            File file = new File(path);
            if (file.exists()) {
                InputStream ins = new FileInputStream(path);
                BufferedInputStream bins = new BufferedInputStream(ins);// 放到缓冲流里面
                OutputStream outs = response.getOutputStream();// 获取文件输出IO流
                BufferedOutputStream bouts = new BufferedOutputStream(outs);
                response.setContentType("application/ostet-stream");// 设置response内容的类型
                response.setHeader(
                        "Content-disposition",
                        "attachment;filename="
                                + URLEncoder.encode(str, "UTF-8"));// 设置头部信息
                int bytesRead = 0;
                byte[] buffer = new byte[8192];
                 //开始向网络传输文件流
                while ((bytesRead = bins.read(buffer, 0, 8192)) != -1) {
                   bouts.write(buffer, 0, bytesRead);
               }
                bouts.flush();// 这里一定要调用flush()方法
                ins.close();
                bins.close();
                outs.close();
                bouts.close();
            } else {
                response.sendRedirect("../error.jsp");
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            File file1=new File(serverPath);
            deleteExcelPath(file1);  //删除临时目录
        }
    }
}