Java实现浏览器端大文件分片上传

目录

• 背景介绍
• 项目介绍
• 需要知识点
• 启动项目
• 项目示范
• 核心讲解
  • 核心原理
• 功能分析
  • 分块上传
  • 秒传功能
  • 断点续传
• 总结
• 参考文献

    // 实例化wu
    var uploader = WebUploader.create({
        pick: {
            id: "#picker",
            label: "点击选择文件"
        },
        formData: {
            uid: 0,
            md5: "",
            chunkSize: chunkSize
        },
        //dnd: "#dndArea",
        //paste: "#uploader",
        swf: "js/Uploader.swf",
        chunked: true,
        chunkSize: chunkSize, // 字节 1M分块
        threads: 3,
        server: "index/fileUpload",
        auto: false,

        // 禁掉全局的拖拽功能。这样不会出现图片拖进页面的时候，把图片打开。
        disableGlobalDnd: true,
        fileNumLimit: 1024,
        fileSizeLimit: 1024 * 1024 * 1024,    // 200 M
        fileSingleSizeLimit: 1024 * 1024 * 1024    // 50 M
    });

 public void uploadFileRandomAccessFile(MultipartFileParam param) throws IOException {
        String fileName = param.getName();
        String tempDirPath = finalDirPath + param.getMd5();
        String tempFileName = fileName + "_tmp";
        File tmpDir = new File(tempDirPath);
        File tmpFile = new File(tempDirPath, tempFileName);
        if (!tmpDir.exists()) {
            tmpDir.mkdirs();
        }

        RandomAccessFile accessTmpFile = new RandomAccessFile(tmpFile, "rw");
        long offset = CHUNK_SIZE * param.getChunk();
        //定位到该分片的偏移量
        accessTmpFile.seek(offset);
        //写入该分片数据
        accessTmpFile.write(param.getFile().getBytes());
        // 释放
        accessTmpFile.close();

        boolean isOk = checkAndSetUploadProgress(param, tempDirPath);
        if (isOk) {
            boolean flag = renameFile(tmpFile, fileName);
            System.out.println("upload complete !!" + flag + " name=" + fileName);
        }
    }

    public void uploadFileByMappedByteBuffer(MultipartFileParam param) throws IOException {
            String fileName = param.getName();
            String uploadDirPath = finalDirPath + param.getMd5();
            String tempFileName = fileName + "_tmp";
            File tmpDir = new File(uploadDirPath);
            File tmpFile = new File(uploadDirPath, tempFileName);
            if (!tmpDir.exists()) {
                tmpDir.mkdirs();
            }

            RandomAccessFile tempRaf = new RandomAccessFile(tmpFile, "rw");
            FileChannel fileChannel = tempRaf.getChannel();

            //写入该分片数据
            long offset = CHUNK_SIZE * param.getChunk();
            byte[] fileData = param.getFile().getBytes();
            MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, offset, fileData.length);
            mappedByteBuffer.put(fileData);
            // 释放
            FileMD5Util.freedMappedByteBuffer(mappedByteBuffer);
            fileChannel.close();

            boolean isOk = checkAndSetUploadProgress(param, uploadDirPath);
            if (isOk) {
                boolean flag = renameFile(tmpFile, fileName);
                System.out.println("upload complete !!" + flag + " name=" + fileName);
            }
        }

/**
     * 秒传判断，断点判断
     *
     * @return
     */
    @RequestMapping(value = "checkFileMd5", method = RequestMethod.POST)
    @ResponseBody
    public Object checkFileMd5(String md5) throws IOException {
        Object processingObj = stringRedisTemplate.opsForHash().get(Constants.FILE_UPLOAD_STATUS, md5);
        if (processingObj == null) {
            return new ResultVo(ResultStatus.NO_HAVE);
        }
        String processingStr = processingObj.toString();
        boolean processing = Boolean.parseBoolean(processingStr);
        String value = stringRedisTemplate.opsForValue().get(Constants.FILE_MD5_KEY + md5);
        if (processing) {
            return new ResultVo(ResultStatus.IS_HAVE, value);
        } else {
            File confFile = new File(value);
            byte[] completeList = FileUtils.readFileToByteArray(confFile);
            List<String> missChunkList = new LinkedList<>();
            for (int i = 0; i < completeList.length; i++) {
                if (completeList[i] != Byte.MAX_VALUE) {
                    missChunkList.add(i + "");
                }
            }
            return new ResultVo<>(ResultStatus.ING_HAVE, missChunkList);
        }
    }