前后端分离（Vue+SpringBoot）实现下载功能

后端：

@GetMapping("/down")
    public void fileinfo(String path,HttpServletRequest request, HttpServletResponse response) {
        // 其余处理略
        InputStream inputStream = null;
        OutputStream outputStream = null;
        try {
          File file = new File(path);
          if(!file.exists()){
            response.setStatus(404);
            throw new RuntimeException("文件不存在..");
          }
          response.setContentType("application/force-download");// 设置强制下载不打开
          response.addHeader("Content-Disposition", "attachment;fileName=" + new String(file.getName().getBytes("UTF-8"),"iso-8859-1"));
          inputStream = new BufferedInputStream(new FileInputStream(path));
          outputStream = response.getOutputStream();
          byte[] buf = new byte[1024];
          int len;
          while ((len = inputStream.read(buf)) > 0) {
            outputStream.write(buf, 0, len);
          }
          response.flushBuffer();
        } catch (IOException e) {
          response.setStatus(404);
          e.printStackTrace();
        } finally {
          if (inputStream != null) {
            try {
              inputStream.close();
            } catch (IOException e) {
               
            }
          }
          if (outputStream != null) {
            try {
              outputStream.close();
            } catch (IOException e) {
            }
          }
        }
      }

前端：

down(path,fileName){
      this.$api.fileinfo.down(path,fileName).then(res => {
      if (!res || res.size === 0) {
      Vue.prototype['$message'].warning('文件下载失败')
      return
    }
    if (typeof window.navigator.msSaveBlob !== 'undefined') {
      window.navigator.msSaveBlob(new Blob([res.data]), fileName)
    } else {
      let url = window.URL.createObjectURL(new Blob([res.data]))
          var aLink = document.createElement("a");
          aLink.style.display = "none";
          aLink.href = url;
          aLink.setAttribute("download", fileName);
          document.body.appendChild(aLink);
          aLink.click();
          document.body.removeChild(aLink); //下载完成移除元素
          window.URL.revokeObjectURL(url); //释放掉blob对象
      }})
    }