npm i axios spark-md5

import axios from 'axios';
import { useRef, useState } from 'react';

// 定義文件分片大?。ɡ?5MB）
const CHUNK_SIZE = 5 * 1024 * 1024;

/** 解析當(dāng)前頁面功能 */
export default function FileUploader() {
  const [file, setFile] = useState(null); // 用于存儲(chǔ)用戶選擇的文件
  const [uploadProgress, setUploadProgress] = useState(0); // 上傳進(jìn)度
  const uploading = useRef(false); // 用于防止重復(fù)觸發(fā)上傳邏輯

  // 當(dāng)用戶選擇文件時(shí)觸發(fā)
  const handleFileChange = (e) => {
    setFile(e.target.files[0]); // 將選擇的文件存入狀態(tài)
    setUploadProgress(0); // 重置上傳進(jìn)度
  };

  // 計(jì)算文件的唯一標(biāo)識(shí) (哈希)
  const calculateFileHash = async (file) => {
    return new Promise((resolve) => {
      const reader = new FileReader();
      reader.onload = (e) => {
        const sparkMD5 = require('spark-md5');
        const hash = sparkMD5.ArrayBuffer.hash(e.target.result);
        resolve(hash);
      };
      reader.readAsArrayBuffer(file);
    });
  };

  // 開始文件上傳
  const handleUpload = async () => {
    if (!file || uploading.current) return; // 如果未選擇文件或正在上傳，則直接返回

    uploading.current = true; // 標(biāo)記為正在上傳
    const fileHash = await calculateFileHash(file); // 獲取文件的唯一標(biāo)識(shí)（哈希值）
    console.log('fileHash', fileHash);
    const totalChunks = Math.ceil(file.size / CHUNK_SIZE); // 計(jì)算文件分片總數(shù)
    // 檢查哪些分片已經(jīng)上傳
    const { data: uploadedChunks } = await axios.post(
      'http://localhost:5000/check',
      {
        fileName: file.name,
        fileHash,
      },
    );

    // 上傳未完成的分片
    for (let chunkIndex = 0; chunkIndex < totalChunks; chunkIndex++) {
      if (uploadedChunks?.includes(chunkIndex)) {
        console.log('跳過chunkIndx', chunkIndex);
        setUploadProgress(((chunkIndex + 1) / totalChunks) * 100); // 更新進(jìn)度
        continue; // 跳過已經(jīng)上傳的分片
      }
      console.log('上傳chunkIndx', chunkIndex);
      // 創(chuàng)建當(dāng)前分片
      const start = chunkIndex * CHUNK_SIZE; // 分片起始字節(jié)
      const end = Math.min(file.size, start + CHUNK_SIZE); // 分片結(jié)束字節(jié)
      const chunk = file.slice(start, end); // 獲取分片

      // 上傳分片
      const formData = new FormData();
      formData.append('chunk', chunk); // 當(dāng)前分片
      formData.append('fileName', file.name); // 文件名
      formData.append('fileHash', fileHash); // 文件唯一標(biāo)識(shí)
      formData.append('chunkIndex', chunkIndex); // 分片索引

      await axios.post(
        `http://localhost:5000/upload?fileHash=${fileHash}&chunkIndex=${chunkIndex}&fileName=${file.name}`,
        formData,
        {
          onUploadProgress: (progressEvent) => {
            const progress =
              ((chunkIndex + progressEvent.loaded / progressEvent.total) /
                totalChunks) *
              100;
            setUploadProgress(progress); // 實(shí)時(shí)更新上傳進(jìn)度
          },
        },
      );
    }

    // 通知服務(wù)端合并分片
    await axios.post('http://localhost:5000/merge', {
      fileName: file.name,
      fileHash,
      totalChunks,
    });

    alert('上傳成功！');
    uploading.current = false; // 標(biāo)記上傳完成
  };

  return (
    <div style={{ padding: '20px' }}>
      <p>大文件上傳（支持?jǐn)帱c(diǎn)續(xù)傳）</p>
      <input type="file" onChange={handleFileChange} />
      <button onClick={handleUpload}>提交上傳文件</button>
      <div style={{ marginTop: '20px' }}>
        <progress value={uploadProgress} max="100" />
        <div>上傳進(jìn)度：{uploadProgress.toFixed(2)}%</div>
      </div>
    </div>
  );
}

npm i multer fs-extra express cors body-parser

// 文件：server.js
const express = require("express");
const multer = require("multer");
const fs = require("fs");
const bodyParser = require("body-parser");
const path = require("path");
const cors = require("cors");
const app = express();
const uploadDir = path.join(__dirname, "uploads"); // 上傳目錄

// 確保上傳目錄存在
if (!fs.existsSync(uploadDir)) {
  fs.mkdirSync(uploadDir);
}

app.use(cors()); // 允許跨域請(qǐng)求
app.use(bodyParser.json());
app.use(express.json()); // 解析 JSON 請(qǐng)求體

// 檢查已上傳的分片
app.post("/check", (req, res) => {
  const { fileHash } = req.body;
  console.log("fileHash check",fileHash)

  const fileChunkDir = path.join(uploadDir, fileHash); // 分片存儲(chǔ)目錄
  if (!fs.existsSync(fileChunkDir)) {
    return res.json([]); // 如果目錄不存在，返回空數(shù)組
  }

  // 返回已上傳的分片索引
  const uploadedChunks = fs.readdirSync(fileChunkDir).map((chunk) => {
    return parseInt(chunk.split("-")[1]); // 提取分片索引
  });
  res.json(uploadedChunks);
});


// 設(shè)置 multer 中間件，用于處理文件上傳
const storage = multer.diskStorage({
  destination: (req, file, cb) => {
    const fileHash = req.query.fileHash; // 從查詢參數(shù)獲取 fileHash
    const chunkDir = path.join(uploadDir, fileHash);
    // 確保切片目錄存在
    if (!fs.existsSync(chunkDir)) {
      fs.mkdirSync(chunkDir, { recursive: true });
    }
    cb(null, chunkDir);
  },
  filename: (req, file, cb) => {
    const { chunkIndex } = req.query;
    cb(null, `chunk-${chunkIndex}`);
  },
});

const upload = multer({ storage:storage });

// 上傳文件分片
app.post("/upload", upload.single("chunk"), (req, res) => {
    const { fileHash } = req.body;
    res.status(200).send("分片上傳成功");
});


// 合并分片
app.post("/merge", (req, res) => {
  const { fileName, fileHash, totalChunks } = req.body;
  console.log("fileName",req.body)
  const fileChunkDir = path.join(uploadDir, fileHash);
  const filePath = path.join(uploadDir, fileName);

  // 創(chuàng)建可寫流用于最終合并文件
  const writeStream = fs.createWriteStream(filePath);

  for (let i = 0; i < totalChunks; i++) {
    const chunkPath = path.join(fileChunkDir, `chunk-${i}`);
    const data = fs.readFileSync(chunkPath); // 讀取分片
    writeStream.write(data); // 寫入最終文件
    // fs.unlinkSync(chunkPath); // 刪除分片文件--留下來，可以看上傳記錄
  }

  writeStream.end(); // 關(guān)閉流
//   fs.rmdirSync(fileChunkDir); // 刪除分片目錄--留下來，可以看上傳記錄
  res.send("文件合并完成");
});

app.listen(5000, () => {
  console.log("服務(wù)器已啟動(dòng)：http://localhost:5000");
});