java 播放本地视屏

前端 src：视频请求路径

<div class="shiping">
    <video id="video" class="video-js vjs-big-play-centered" controls="controls" poster="">
        <source src="/paper/questions/getVideo" type='video/mp4'>
    </video>
</div>

后端读取视频返回给前端

 /**
     * 获取视屏
     */
    @GetMapping("/paper/questions/getVideo")
    @ResponseBody
    public void getVideo(HttpServletRequest request, HttpServletResponse response)
    {
        //视频资源存储信息
        response.reset();
        //获取从那个字节开始读取文件
        String rangeString = request.getHeader("Range");
        try {
            //获取响应的输出流
            OutputStream outputStream = response.getOutputStream();
            //读取本地视频
            File file = new File("C:\\Users\\cygg\\Desktop\\exam.mp4");
            if(file.exists()){
                RandomAccessFile targetFile = new RandomAccessFile(file, "r");
                long fileLength = targetFile.length();
                //播放
                if(rangeString != null){
                    long range = Long.valueOf(rangeString.substring(rangeString.indexOf("=") + 1, rangeString.indexOf("-")));
                    //设置内容类型
                    response.setHeader("Content-Type", "video/mp4");
                    //设置此次相应返回的数据长度
                    response.setHeader("Content-Length", String.valueOf(fileLength - range));
                    //设置此次相应返回的数据范围
                    response.setHeader("Content-Range", "bytes "+range+"-"+(fileLength-1)+"/"+fileLength);
                    //返回码需要为206，而不是200
                    response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT);
                    //设定文件读取开始位置（以字节为单位）
                    targetFile.seek(range);
                }else {//下载
                    //设置响应头，把文件名字设置好
                    response.setHeader("Content-Disposition", "attachment; filename=video.mp4" );
                    //设置文件长度
                    response.setHeader("Content-Length", String.valueOf(fileLength));
                    //解决编码问题
                    response.setHeader("Content-Type","application/octet-stream");
                }
                byte[] cache = new byte[1024 * 300];
                int flag;
                while ((flag = targetFile.read(cache))!=-1){
                    outputStream.write(cache, 0, flag);
                }
            }else {
                String message = "file: not exists";
                //解决编码问题
                response.setHeader("Content-Type","application/json");
                outputStream.write(message.getBytes(StandardCharsets.UTF_8));
            }
            outputStream.flush();
            outputStream.close();
        } catch (Exception e) {

        }
    }