java 壓縮導出多個excel

簡單介紹下我實現的功能,首先是我的excel上傳，它是以blob字段存儲在oracel數據庫中的，我實現的是循環遍歷blob字段並使用io流進行打包下載，如有需要可自行修改

使用技術有，springMVC，mabits , bootstrap

1.前台

這里給出主要代碼塊

<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>

注意這里點擊按鈕時用的超鏈接，不要用的ajax提交，ajax慎用，我自己一開始使用的ajax，最后無法下載，搞了半天，后來百度，說ajax下載無法調用瀏覽器的下載機制，如果有必要也可以使用（要用form封裝，我這里不再具體介紹，有嘗試的小伙伴，可以共享一下，哈哈）

2. Controller  讀取數據

@RequestMapping(value = "downloadPreHomeWorkZIP")
    public void downloadLetterZIP(trainTraineeWorkModel query, HttpServletResponse response, HttpServletRequest request)
            throws IOException, SQLException {
        String serverPath = request.getSession().getServletContext().getRealPath("/") + "\\upload\\tempExcel";  //設置下載excel的臨時文件夾
        List<File> srcfile = new ArrayList<File>();  //聲明一個集合，用來存放多個Excel文件路徑及名稱
        // 得到路徑下的文件，如果不存在創建文件夾
        File file = new File(serverPath);
        if (!file.exists()) {
            file.mkdir();
        }
        List<Map> employees = employeeService // 查詢學員上傳的課前課后作業 （這里根據自己的需要獲取數據，寫入流中）
                .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();   //定義現在excel文件名稱，注意這里不是壓縮包的名稱
                    ZipUtils.execute(serverPath +"\\"+ filename+ ".xls", blob);   //ZipUtils是我自己定義的一個工具類，因為用到的下載太多了，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
                }
            }
            // 將服務器上存放Excel的文件夾打成zip包
            File zipfile = new File(serverPath+"\\" + "PreWork" + ".zip");
            ZipUtils.zipFiles(srcfile, zipfile);// 實現將多個excel打包成zip文件
            //下載
            ZipUtils.downFile(response, serverPath, "PreWork" + ".zip");  //實現將壓縮包寫入流中，下載到本地，並刪除臨時文件中的壓縮包及文件
            
        }
}

3.使用工具類

這里是我第二步說的自己定義的工具類，我用的maven，需要導入一些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 {
    /** 
     * 將多個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為單個excel的路徑和excel的名稱，blob就是獲取的blob數據
    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;
      }
   
    }  
    
    /**  
     * 刪除目錄下所有的文件;  
     * @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("刪除成功!");    
                }else{    
                    System.out.println("刪除失敗!");    
                }    
            }    
        }    
        return file.delete();    
    }   
    
   
    public static void downFile(HttpServletResponse response,String serverPath, String str) {    
        //下面注釋代碼雖然少，但是慎用，如果使用，壓縮包能下載，但是下載之后臨時文件夾會被鎖住被jvm占用，不能刪除
//        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);// 放到緩沖流里面    
                OutputStream outs = response.getOutputStream();// 獲取文件輸出IO流    
                BufferedOutputStream bouts = new BufferedOutputStream(outs);   
                response.setContentType("application/ostet-stream");// 設置response內容的類型    
                response.setHeader(    
                        "Content-disposition",    
                        "attachment;filename="    
                                + URLEncoder.encode(str, "UTF-8"));// 設置頭部信息    
                int bytesRead = 0;    
                byte[] buffer = new byte[8192];    
                 //開始向網絡傳輸文件流    
                while ((bytesRead = bins.read(buffer, 0, 8192)) != -1) {    
                   bouts.write(buffer, 0, bytesRead);    
               }    
                bouts.flush();// 這里一定要調用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);  //刪除臨時目錄
        }    
    }  
}