springmvc 文件下载

1.jsp页面

<input type="button" onclick="downFile()" value="附件下载"/>

2.js文件部分

//附件下载
function downFile(){
  
  var fileName="${requestScope.customer.fileUri}"; 
  if(fileName=="" || fileName==undefined){
     Dialog.alert("您还没上传文件！");
     return;
  }
  var urlString = "http://localhost:8080${pageContext.request.contextPath}/upload/"+fileName;
  //跳转到后端控制器
  location.href="${pageContext.request.contextPath}/fileupload/download?urlString="+urlString;
}

3.action 部分

/**
* 根据要下载的文件名称
* 上服务器的目录下，下载该文件
* @param request 请求
* @param response 响应
* @throws IOException
*/
@RequestMapping("download")
    public void download(HttpServletRequest request,HttpServletResponse response,String urlString){
        BufferedInputStream dis = null;
        BufferedOutputStream fos = null;


        String fileName = urlString.substring(urlString.lastIndexOf('/') + 1);


        try {


            URL url = new URL(urlString);
            //response.setContentType("application/x-msdownload;");
            response.setContentType("application/octet-stream");
            response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes("utf-8"), "ISO8859-1"));
            response.setHeader("Content-Length", String.valueOf(url.openConnection().getContentLength()));


            dis = new BufferedInputStream(url.openStream());
            fos = new BufferedOutputStream(response.getOutputStream());


            byte[] buff = new byte[2048];
            int bytesRead;
            while (-1 != (bytesRead = dis.read(buff, 0, buff.length))) {
                fos.write(buff, 0, bytesRead);
            }


        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (dis != null)
                try{
                    dis.close();
                }catch (Exception e){
                    e.printStackTrace();
                }
            if (fos != null)
                try{
                    fos.close();
                }catch (Exception e){
                    e.printStackTrace();
                }


        }
    }