java 播放本地视屏

浅浅的花香味﹌ 2024-03-22 15:11 39阅读 0赞

前端 src：视频请求路径

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) {
        
    
            }
        }