java 返回浏览器下载文件

缺乏、安全感 2021-12-10 15:27 514阅读 0赞

@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";
        }