上节我们说了Minio怎么大文件上传,我们是进行了分段上传,然后合并处理,感兴趣的可以去这篇文章,
Springboot Minio最新版大文件上传-CSDN博客
那么今天的主题就是大文件下载,再大文件就需要分段下载,也就需要前端给下载的范围,就是下面的range的参数,我们为了好测试将此字段放入了参数了,实际你可以放入header头部。
下载的Controller类:
@Slf4j
@RestController
public class DownloadController {@Resourceprivate IDownloadProcess downloadProcess;// http://localhost:8082/download?filename=a9500aa2091875f3d02a9b84ae1ab712.mp4&range=bytes=0-52428800// 分段下载的化,支持断点下载,暂停下载,断网恢复下载等。// 我测试就采取这种方式RequestParam,大家真实场景可以放到header里 @RequestHeader(name = "Range", required = false) String range,@GetMapping("/download")public ResponseEntity downloadFile(@RequestParam String filename,@RequestParam(required = false) String range,HttpServletRequest request, HttpServletResponse response) {try {return downloadProcess.downloadFile(filename, range, request, response);} catch (Exception e) {log.error("下载异常|参数:{},{}|{}", filename, range, e);return new ResponseEntity<byte[]>(HttpStatus.INTERNAL_SERVER_ERROR);}}}
IDownloadProcess:定义下载接口
public interface IDownloadProcess {ResponseEntity downloadFile(String filename, String range, HttpServletRequest request, HttpServletResponse response) throws IOException, InvalidKeyException, InvalidResponseException, InsufficientDataException, NoSuchAlgorithmException, ServerException, InternalException, XmlParserException, ErrorResponseException, Exception;
}
DownloadProcessImpl:下载实现类,
我们可以传range参数来处理要下载的kb数范围,当然也可以不传递就是下载全部,
1.首先就是获取桶里文件信息,文件大小什么的都能获取
2.查看是范围下载还是全部下载
3.设置响应下载的类型和请求头
4.获取minio的流文件
5.将流文件遍历读取放入缓冲中
6.然后写入到OutputStream流中,然后刷新就可以啦。
@Slf4j
@Service
public class DownloadProcessImpl implements IDownloadProcess {@Resourceprivate MinioClient minioClient;@Resourceprivate MinioConfig minioConfig;// 完整文件与分片文件下载@Overridepublic ResponseEntity downloadFile(String filename, String range, HttpServletRequest request, HttpServletResponse response) throws Exception {ResponseEntity<byte[]> responseEntity = null;BufferedOutputStream os = null;GetObjectResponse stream = null;if (StringUtils.isNotBlank(filename)) {log.info("要下载的文件:{}", filename);//String range = request.getHeader("Range");log.info("current request rang:{}", range);// 获取桶里文件信息StatObjectResponse statObjectResponse = minioClient.statObject(StatObjectArgs.builder().bucket(minioConfig.getBucketName()).object(filename).build());//开始下载位置long startByte = 0;//结束下载位置long endByte = statObjectResponse.size() - 1;log.info("文件开始位置:{},文件结束位置:{},文件总长度:{}", startByte, endByte, statObjectResponse.size());// 有range的话,需要根据前端下载长度进行下载,也就是分段下载// 例如:range=bytes=0-52428800if (StringUtils.isNotBlank(range) && range.contains("bytes=") && range.contains("-")) {range = range.substring(range.lastIndexOf("=") + 1).trim();String[] ranges = range.split("-");//判断range的类型if (ranges.length == 1) {//类型一:bytes=-2343if (range.startsWith("-")) endByte = Long.parseLong(ranges[0]);//类型二:bytes=2343-if (range.endsWith("-")) startByte = Long.parseLong(ranges[0]);}//类型三:bytes=22-2343else if (ranges.length == 2) {startByte = Long.parseLong(ranges[0]);endByte = Long.parseLong(ranges[1]);}}//要下载的长度long contentLength = endByte - startByte + 1;//文件类型String contentType = request.getServletContext().getMimeType(filename);//解决下载文件时文件名乱码问题byte[] fileNameBytes = filename.getBytes(StandardCharsets.UTF_8);filename = new String(fileNameBytes, 0, fileNameBytes.length, StandardCharsets.ISO_8859_1);//各种响应头设置---------------------------------------------------------------------------------------------//支持断点续传,获取部分字节内容:response.setHeader("Accept-Ranges", "bytes");//http状态码要为206:表示获取部分内容,SC_PARTIAL_CONTENT,部分浏览器不支持,所以改成SC_OKresponse.setStatus(HttpServletResponse.SC_OK);response.setContentType(contentType);response.setHeader("Last-Modified", statObjectResponse.lastModified().toString());//inline表示浏览器直接使用,attachment表示下载,fileName表示下载的文件名response.setHeader("Content-Disposition", "attachment;filename=" + filename);response.setHeader("Content-Length", String.valueOf(contentLength));//Content-Range,格式为:[要下载的开始位置]-[结束位置]/[文件总大小]response.setHeader("Content-Range", "bytes " + startByte + "-" + endByte + "/" + statObjectResponse.size());response.setHeader("ETag", "\"".concat(statObjectResponse.etag()).concat("\""));response.setContentType("application/octect-stream;charset=UTF-8");try {// 获取文件流stream = minioClient.getObject(GetObjectArgs.builder().bucket(statObjectResponse.bucket()).object(statObjectResponse.object()).offset(startByte).length(contentLength).build());os = new BufferedOutputStream(response.getOutputStream());// 将读取的文件写入到OutputStreambyte[] buffer = new byte[1024];long bytesWritten = 0;int bytesRead = -1;while ((bytesRead = stream.read(buffer)) != -1) {if (bytesWritten + bytesRead > contentLength) {os.write(buffer, 0, (int) (contentLength - bytesWritten));break;} else {os.write(buffer, 0, bytesRead);bytesWritten += bytesRead;}}os.flush();response.flushBuffer();log.info("下载完毕");// 返回对应http状态responseEntity = new ResponseEntity<byte[]>(buffer, HttpStatus.OK);} finally {if (os != null) os.close();if (stream != null) stream.close();}}return responseEntity;}
}
测试链接:
下50M的情况
http://localhost:8082/download?filename=a9500aa2091875f3d02a9b84ae1ab712.mp4&range=bytes=0-52428800
从50m再次下载50m
http://localhost:8082/download?filename=a9500aa2091875f3d02a9b84ae1ab712.mp4&range=bytes=52428800-104857600
都下载到了前端本地以后由客户端进行合并操作就好了。