java 返回浏览器下载文件

最新推荐文章于 2024-01-11 17:25:08 发布

不甘平凡--liang

最新推荐文章于 2024-01-11 17:25:08 发布

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分类专栏： java

本文链接：https://blog.youkuaiyun.com/weixin_44990255/article/details/95485857

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该博客围绕Java返回下载文件展开，虽未给出具体内容，但可知核心是利用Java技术实现文件的下载返回功能，在后端开发中，这是常见且重要的功能，可用于多种业务场景。

@RequestMapping("downloadFile")
    public String downloadFile(HttpServletRequest request,
                               HttpServletResponse response,String fileName){
        if(StringUtils.isNotBlank(fileName)){
            String zipFileName = fileName+".zip";
            File file = new File(rootPath+zipFileName);
            if(file.exists()){
                byte[] buffer = new byte[1024];
                FileInputStream fis = null;
                BufferedInputStream bis = null;
                OutputStream os = null;
                String finalFileName = "";
                try {
                    final String userAgent = request.getHeader("USER-AGENT");
                    if(StringUtils.contains(userAgent, "MSIE")||StringUtils.contains(userAgent,"Trident")){//IE浏览器
                        finalFileName = URLEncoder.encode(zipFileName,"UTF8");
                    }else if(StringUtils.contains(userAgent, "Mozilla")){//google,火狐浏览器
                        finalFileName = new String(zipFileName.getBytes(), "ISO8859-1");
                    }else{
                        finalFileName = URLEncoder.encode(zipFileName,"UTF8");//其他浏览器
                    }
                    response.setCharacterEncoding("UTF-8");
                    response.setContentType("application/force-download");// 设置强制下载不打开
                    response.addHeader("Content-Disposition", "attachment;fileName=" + finalFileName);// 设置文件名
                    fis = new FileInputStream(file);
                    bis = new BufferedInputStream(fis);
                    os = response.getOutputStream();
                    int i = bis.read(buffer);
                    while (i != -1) {
                        os.write(buffer, 0, i);
                        i = bis.read(buffer);
                    }
                    return "下载成功";
                }catch (Exception e){

                }finally {

                    if(fis != null){
                        try {
                            fis.close();
                        }catch (Exception e){
                            e.printStackTrace();
                        }
                    }
                    if(bis != null){
                        try {
                            bis.close();
                        }catch (Exception e){
                            e.printStackTrace();
                        }
                    }
                    if(os != null){
                        try {
                            os.flush();
                            os.close();
                        }catch (Exception e){
                            e.printStackTrace();
                        }
                    }
                }
            }
        }
        return "下载失败";
    }