SpringBoot上传文件返回进度

　　导入的包    commons-fileupload    commons-fileupload    1.4   // 根据自己需要     org.projectlombok    lombok    true 进度返回类**  * @author Linux＂s user: FB  * device: Windows 11  * create time: 2022/3/2  * remarks: []  */ @Data public class Progress implements Cloneable {      private long bytesRead;     private long contentLength;     private long items;      private static final Progress progress = new Progress();      public static Progress getInstance() {         return progress.clone();     }      @Override     public Progress clone() {         try {             return (Progress) super.clone();         } catch (CloneNotSupportedException e) {             throw new AssertionError();         }     } }文件上传监听器@Component public class FileUploadListener implements ProgressListener {      private final Map map = new ConcurrentHashMap<>();      private final HttpServletRequest request;      public FileUploadListener(HttpServletRequest request) {         this.request = request;     }      /**      * @param bytesRead 当前上传大小      * @param contentLength 总大小      * @param items 当前上传个数      */     @Override     public void update(long bytesRead, long contentLength, int items) {         Progress progress = Progress.getInstance();         progress.setBytesRead(bytesRead);         progress.setContentLength(contentLength);         progress.setItems(items);         // 可替换成 redis / session         map.put(request.getHeader(＂file＂), progress);     }      public Progress getMap(String header) {         return map.get(header);     } }  文件上传解析器@Component public class CustomMultipartResolver extends CommonsMultipartResolver {      private final FileUploadListener fileUploadListener;      public CustomMultipartResolver(FileUploadListener fileUploadListener) {         this.fileUploadListener = fileUploadListener;     }      @Override     protected MultipartParsingResult parseRequest(HttpServletRequest request) throws MultipartException {         String encoding = determineEncoding(request);         FileUpload fileUpload = prepareFileUpload(encoding);         // 设置上传监听器         fileUpload.setProgressListener(fileUploadListener);         try {             List fileItems = ((ServletFileUpload)fileUpload).parseRequest(request);             return this.parseFileItems(fileItems, encoding);         } catch (FileUploadBase.SizeLimitExceededException var5) {             throw new MaxUploadSizeExceededException(fileUpload.getSizeMax(), var5);         } catch (FileUploadBase.FileSizeLimitExceededException var6) {             throw new MaxUploadSizeExceededException(fileUpload.getFileSizeMax(), var6);         } catch (FileUploadException var7) {             throw new MultipartException(＂Failed to parse multipart servlet request＂, var7);         }     } } Controller 接口@RestController public class UploadController {      private final UploadService uploadService;      public UploadController(UploadService uploadService) {         this.uploadService = uploadService;     }      @PostMapping(＂/upload＂)     public R upload (MultipartFile[] file) {         uploadService.upload(file);         return R.ok().message(＂上传成功＂);     }      @GetMapping(＂/progress＂)     public R progress (HttpServletRequest request) {         String file = request.getHeader(＂file＂);         if (StringUtils.isNullOrEmpty(file)) return R.error().message(＂需要 header: [file=xxx] 标识＂);          return R.ok().message(uploadService.getUploadDone(file) ? ＂上传完成＂ : ＂上传中...＂).data(uploadService.getProgressStyle(file));     } } Service 实现类@Service public class UploadServiceImpl implements UploadService {      private final StringBuilder stringBuilder = new StringBuilder();      private final Map map = new HashMap<>(4);      // 构造注入上传监听     private final FileUploadListener listener;      public UploadServiceImpl(FileUploadListener listener) {         this.listener = listener;     }      /**      * 返回进度参数信息      *         ＂progress＂: ＂[##########] 100%＂,      *         ＂item＂: 3,      *         ＂percent＂: 100,      *         ＂status＂: ＂over＂      * @param header 文件标识      * @return Map      */     // 进度 Map     @Override     public Map getProgressStyle (String header) {         Progress progress = listener.getMap(header);         if (progress == null) throw new CustomException(＂未上传文件＂);          long read = progress.getBytesRead();         long percent = 0;         if (read != 0) percent = (read * 100) / progress.getContentLength();         map.put(＂percent＂, percent);         map.put(＂status＂, percent == 100 ? ＂over＂ : ＂active＂);         map.put(＂progress＂, getStyleOfCount(percent));         map.put(＂item＂, progress.getItems());         return map;     }      /**      * 判断文件是否上传文成      * @param header 文件标识      * @return true / false      */     @Override     public boolean getUploadDone(String header) {         Progress progress = listener.getMap(header);         if (progress == null) throw new CustomException(＂未上传文件＂);          return progress.getBytesRead() == progress.getContentLength();     }      /**      * 文件保存操作      * 这里做存储文件等其他操作操作      * 这里也需要返回进度的话，上面的进度需要 / 2，各记 50%      * @param file 文件      */     @Override     public void upload(MultipartFile[] file) {         Arrays.asList(file).forEach(f -> {             if (f.isEmpty()) {                 throw new CustomException(＂文件为空＂);             } else {                 System.out.println(＂文件名：＂ + f.getOriginalFilename());                 System.out.println(＂文件大小：＂ + f.getSize());                 System.out.println(＂文件类型：＂ + f.getContentType());             }         });     }      /**      * 进度样式      * @param percent 进度百分比      * @return [###       ] 30%      */     private String getStyleOfCount (long percent) {         stringBuilder.setLength(0);         stringBuilder.append(＂[＂);         for (int i = 0; i < percent / 10; i++) {             stringBuilder.append(＂#＂);         }         for (int i = 0; i < 10 - (percent / 10); i++) {             stringBuilder.append(＂ ＂);         }         stringBuilder.append(＂] ＂).append(percent).append(＂%＂);         return stringBuilder.toString();     } } 效果
　　上传准备
　　点击上传后，file 是文件的唯一标识，上传时也需要传入
　　然后看效果（item 是文件个数）
　　项目地址：
　　Spring Boot 上传返回进度【最新】 - 小波博客