java 通過url下載文件到瀏覽器

前端傳來url地址與文件名，下載文件到瀏覽器

• 代碼 (這裏模擬，直接在代碼裏寫了url,可以拼接在url後進行截取)
• 請求接口

    @GetMapping("/findOperatorBarVO2")
    @ApiOperation(value = "下載")
    public void findOperatorCharBar2(HttpServletResponse response)throws IOException{
        toDownload(response);
    }
  

• 下載方法

       public static void toDownload( HttpServletResponse response)  {
        ServletOutputStream out = null;
        InputStream inputStream = null;
  
        try {
            //路徑
            String path = "http://10.202.61.66:11111/KEDFSFile/M00/00/1E/Cso9Ql7Z61CAZtQcAAAGqKgzHds335.txt";
            // 取得文件的後綴名。
            String ext = path.substring(path.lastIndexOf(".") + 1).toLowerCase();
            //文件名
            String pdfName = "問題."+ext;
            // 獲取外部文件流
            URL url = new URL(path);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(3 * 1000);
            //防止屏蔽程序抓取而返回403錯誤
            conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
            inputStream = conn.getInputStream();
            /**
             * 輸出文件到瀏覽器
             */
            int len = 0;
            // 輸出 下載的響應頭，如果下載的文件是中文名，文件名需要經過url編碼
            response.setContentType("application/x-download");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(pdfName, "UTF-8"));
            response.setHeader("Cache-Control", "no-cache");
            out = response.getOutputStream();
            byte[] buffer = new byte[1024];
            while ((len = inputStream.read(buffer)) > 0) {
                out.write(buffer, 0, len);
            }
            out.flush();
        } catch (Exception e) {
  
            e.printStackTrace();
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (Exception e) {
                }
            }
            if (out != null) {
                try {
                    out.close();
                } catch (Exception e) {
                }
            }
        }
    }
  
  

• 前端代碼

        window.location.href = "http://localhost:9090/xx/evaOperator/findOperatorBarVO2";