从服务器路径 / 本地指定路径下载文件

前端（普通blod下载方式）

//点击下载
   downloadInfo() {
     this.axiosFun() //axios请求
       .then(function (response) {
         var blob = new Blob([response], { type: "application/x-xls" }); //创建一个blob对象
         var a = document.createElement("a"); //创建一个<a></a>标签
         a.href = URL.createObjectURL(blob); // response is a blob
         var patt = new RegExp('filename=([^;]+\\.[^\\.;]+);*')
         var contentDisposition = decodeURL(res.headers['content-disposition'])
         var result = patt.exec(contentDisposition)
         var fileName = result[1]
         fileName = fileName.replace(/\"/g,'')
         a.download = fileName; //文件名称
         a.style.display = "none";
         document.body.appendChild(a);
         a.click();
         a.remove();
         // this.$refs.upload.clearFiles()
       })
       .catch(function (err) {
         console.log(err);
       });
   },

后端

controller 和 service接口太过简单， 直接 Impl

public void exportErr(HttpServletResponse response, String tmpId) {
        InputStream inputStream = null;
        OutputStream outputStream = null;
        try {
            File file = new File("文件在服务器的路径");
            String fileName = new String(file.getName().getBytes("gb2312"),"ISO8859-1");
            response.setContentType("application/vnd.ms-excel;chartset=utf-8");
            response.setHeader("Content-Disposition","attachment;filename=" + fileName);
            inputStream = new BufferedInputStream(new FileInputStream(file));
            outputStream = response.getOutputStream();
            byte[] buf = new byte[1024];
            int len;
            while ((len = inputStream.read(buf))>0){
                outputStream.write(buf,0,len);
            }
            response.flushBuffer();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
        //别忘了关闭流
            if (inputStream!=null){
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (outputStream!=null){
                try {
                    outputStream.close();
                }catch (IOException e){
                    e.printStackTrace();
                }
            }
        }
    }

结束