文件下载

1，struts2文件下载：

　　

1)Action配置

　　// 下载，
    public String downloadFile() throws Exception {
        return SUCCESS;
    }

　　// 文件下载（读取文件流的入口，必须返回一个文件输入流）
  public InputStream getDownloadFile() throws FileNotFoundException {
      System.out.println(riskEvent.getFilePath());
      // 图片路径
      String fileName =basePath +"/"+ riskEvent.getFilePath();
      // 如果下载文件名为中文，进行字符编码转换
      getHttpResponse().setHeader("Content-Disposition","attachment;fileName="+riskEvent.getFilePath());
      InputStream inputStream = new FileInputStream(fileName);
      System.out.println(inputStream);
      return inputStream;
  }

2）xml的配置

　　    <action name="downloadFile" class="riskSurveyAction" method="downloadFile" > 
             <result name="success" type="stream"> 
                   <param name="contentDisposition">  
                     attachment;filename="${riskEvent.filePath}"  
                   </param>  
                  <param name="inputName">downloadFile</param>
                 <param name="bufferSize">2048</param> 
             </result> 
          </action>

2，自己写的下载

/**
  * 下载小票
  * @throws IOException
  */
 public void downLoadFile() throws IOException{
  String fileName = riskEvent.getFilePath();
  // 图片路径
  String filePath = basePath +"/"+ fileName.substring(0, fileName.lastIndexOf(".")) + "/"+fileName;
  HttpServletResponse response = getHttpResponse();
  File file = new File(filePath);
  long len = file.length();
  down(file, fileName, response);
 }
 
    public void down(File f,String filename,HttpServletResponse response)
    {
     response.reset();
     response.setHeader("content-disposition","attachment; filename="+filename); //设置下载的文件名
     long fileLength=f.length();
     String length1=String.valueOf(fileLength);
     response.setHeader("Content_Length",length1); //下载文件的大小
     InputStream in=null;
     OutputStream out = null;
     try{
      in = new FileInputStream( f );
      out = response.getOutputStream();
      byte[] buffer = new byte[2097152];
      int ins = in.read(buffer);//读取字节到buffer中
      //ins == -1 时 。就已经是文件的结尾了
      while ( ins != -1 ) {
       out.write(buffer, 0, ins);//将缓存buffer中的数据写到文件中
       ins = in.read(buffer);
      }
      in.close();
      out.flush();
      out.close();
     }catch (Exception e) {
         System.out.println("--下载发生异常--");
         try {
                    in.close();
                    out.flush();
                    out.close();
                } catch (IOException e1) {
                    System.out.println("--关闭发生异常--");
                    in = null;
                    out = null;
                    e1.printStackTrace();
                }
            }
    }