java下載Excel模板（工具類）

　　　　一次文件下載記錄

　　一次不成熟的文件下載操做記錄，但願能對須要的人有所幫助。

1.前端代碼

$("#downloadModel").click(function(){
　　var modelName = "設備信息導入模板.xls";
　　window.location.href = commenUrl +"/importAndExport/downloadModel?modelName="+modelName;
});

2.控制層接收

1 @RequestMapping(value = "/downloadModel", method = RequestMethod.GET)
2 public void  downloadModel(HttpServletRequest request,HttpServletResponse response,String modelName) {
3     try {                
4         importAndExportService.downloadModel(modelName,request,response);
5     } catch (Exception e) {
6         e.printStackTrace();
7     }
8 }    

3.實現下載功能

　　@SuppressWarnings("resource")
   @Override
   public void downloadBindModel(String modelName, HttpServletRequest request,
            HttpServletResponse response) throws Exception {
        //獲取模板存放的路徑
        String path=request.getSession().getServletContext().getRealPath("/")+"/excelTemplate/";
        InputStream is=new FileInputStream(new File(path + modelName));
        HSSFWorkbook hssfWorkbook=new HSSFWorkbook(is);
        //下載
        DownloadUtil dUtil=new DownloadUtil();
        ByteArrayOutputStream os=new ByteArrayOutputStream();
        hssfWorkbook.write(os);
        dUtil.download(os, response, modelName);
        os.flush();
        os.close();
        is.close();
    }

4.工具類代碼

public class DownloadUtil{

  /**
   * @param filePath 要下載的文件路徑
   * @param returnName 返回的文件名
   * @param response HttpServletResponse
   * @param delFlag 是否刪除文件
   */
  protected void download(String filePath, String returnName, HttpServletResponse response, boolean delFlag){
    this.prototypeDownload(new File(filePath), returnName, response, delFlag);
  }


  /**
   * @param file 要下載的文件
   * @param returnName 返回的文件名
   * @param response HttpServletResponse
   * @param delFlag 是否刪除文件
   */
  protected void download(File file,String returnName,HttpServletResponse response,boolean delFlag){
    this.prototypeDownload(file, returnName, response, delFlag);
  }

  /**
   * @param file 要下載的文件
   * @param returnName 返回的文件名
   * @param response HttpServletResponse
   * @param delFlag 是否刪除文件
   */
  public void prototypeDownload(File file,String returnName,HttpServletResponse response,boolean delFlag){
    // 下載文件
    FileInputStream inputStream = null;
    ServletOutputStream outputStream = null;
    try {
      if(!file.exists()) {return;}
      response.reset();
      //設置響應類型    PDF文件爲"application/pdf"，WORD文件爲："application/msword"， EXCEL文件爲："application/vnd.ms-excel"。
      response.setContentType("application/octet-stream;charset=utf-8");
      //設置響應的文件名稱,並轉換成中文編碼
      //returnName = URLEncoder.encode(returnName,"UTF-8");
      returnName = response.encodeURL(new String(returnName.getBytes(),"iso8859-1"));    //保存的文件名,必須和頁面編碼一致,不然亂碼
      //attachment做爲附件下載；inline客戶端機器有安裝匹配程序，則直接打開；注意改變配置，清除緩存，不然可能不能看到效果
      response.addHeader("Content-Disposition",   "attachment;filename="+returnName);
      //將文件讀入響應流
      inputStream = new FileInputStream(file);
      outputStream = response.getOutputStream();
      int length = 1024;
      int readLength=0;
      byte buf[] = new byte[1024];
      readLength = inputStream.read(buf, 0, length);
      while (readLength != -1) {
        outputStream.write(buf, 0, readLength);
        readLength = inputStream.read(buf, 0, length);
      }
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      try {
        outputStream.flush();
      } catch (IOException e) {
        e.printStackTrace();
      }
      try {
        outputStream.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
      try {
        inputStream.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
      //刪除原文件
      if(delFlag) {
        file.delete();
      }
    }
  }
  
  /**
   * @param byteArrayOutputStream 將文件內容寫入ByteArrayOutputStream
   * @param response 寫入response
   * @param returnName 返回的文件名
   * @throws IOException
   */
  public void download(ByteArrayOutputStream byteArrayOutputStream, HttpServletResponse response, String returnName) throws IOException {
    response.setContentType("application/octet-stream;charset=utf-8");
    returnName = response.encodeURL(new String(returnName.getBytes(),"iso8859-1"));            //保存的文件名,必須和頁面編碼一致,不然亂碼
    response.addHeader("Content-Disposition",   "attachment;filename=" + returnName);
    response.setContentLength(byteArrayOutputStream.size());

    ServletOutputStream outputstream = response.getOutputStream();    //取得輸出流
    byteArrayOutputStream.writeTo(outputstream);                    //寫到輸出流
    byteArrayOutputStream.close();                                    //關閉
    outputstream.flush();                                            //刷數據
  }
}