vue通过实现大文件切片上传

Vue可以通过以下步骤实现大文件切片上传：

1. 将大文件切成多个小文件。可以使用JavaScript中的Blob.slice()方法将文件分成多个块。

2. 使用XMLHttpRequest对象将每个块上传到服务器。可以使用Vue的axios库来发送HTTP请求。

3. 在服务器端将每个块合并成一个完整的文件。可以使用Node.js的fs模块来处理文件操作。

4. 如果需要，可以在上传过程中显示上传进度。可以使用Vue的组件来显示进度条。

以下是一个示例代码：

<template>
  <div>
    <input type="file" @change="handleFileChange" />
    <button @click="uploadFile">Upload</button>
    <div v-if="uploading">
      Uploading... {{ progress }}%
    </div>
  </div>
</template>

<script>
import axios from 'axios';

export default {
  data() {
    return {
      file: null,
      uploading: false,
      progress: 0,
    };
  },
  methods: {
    handleFileChange(event) {
      this.file = event.target.files[0];
    },
    async uploadFile() {
      const CHUNK_SIZE = 1000000; // 1MB
      const fileSize = this.file.size;
      const chunks = Math.ceil(fileSize / CHUNK_SIZE);
      let currentChunk = 0;

      this.uploading = true;

      while (currentChunk < chunks) {
        const start = currentChunk * CHUNK_SIZE;
        const end = Math.min(start + CHUNK_SIZE, fileSize);
        const chunk = this.file.slice(start, end);

        const formData = new FormData();
        formData.append('file', chunk);
        formData.append('chunk', currentChunk);
        formData.append('chunks', chunks);

        await axios.post('/upload', formData, {
          onUploadProgress: (progressEvent) => {
            this.progress = Math.round((100 * progressEvent.loaded) / progressEvent.total);
          },
        });

        currentChunk++;
      }

      this.uploading = false;
      this.progress = 0;
    },
  },
};
</script>

在服务器端，可以使用以下代码来处理文件上传和合并：

const fs = require('fs');
const path = require('path');
const express = require('express');
const app = express();

app.post('/upload', (req, res) => {
  const file = req.files.file;
  const chunk = parseInt(req.body.chunk);
  const chunks = parseInt(req.body.chunks);

  const fileName = file.name;
  const filePath = path.join(__dirname, 'uploads', fileName);

  const stream = fs.createWriteStream(filePath, { flags: chunk === 0 ? 'w' : 'a' });
  stream.on('finish', () => {
    if (chunk === chunks - 1) {
      // All chunks have been uploaded. Merge the file.
      const mergedFilePath = path.join(__dirname, 'uploads', `merged-${fileName}`);
      const mergedStream = fs.createWriteStream(mergedFilePath);
      for (let i = 0; i < chunks; i++) {
        const chunkFilePath = path.join(__dirname, 'uploads', `${fileName}.${i}`);
        const chunkStream = fs.createReadStream(chunkFilePath);
        chunkStream.pipe(mergedStream, { end: false });
        chunkStream.on('end', () => {
          fs.unlink(chunkFilePath, (error) => {
            if (error) {
              console.error(`Error deleting chunk file ${chunkFilePath}: ${error.message}`);
            }
          });
        });
      }
      mergedStream.on('finish', () => {
        res.status(200).send('File uploaded successfully!');
      });
      mergedStream.on('error', (error) => {
        console.error(`Error merging file: ${error.message}`);
        res.status(500).send('Error merging file');
      });
    } else {
      res.status(200).send('Chunk uploaded successfully!');
    }
  });
  stream.on('error', (error) => {
    console.error(`Error writing chunk file: ${error.message}`);
    res.status(500).send('Error writing chunk file');
  });

  file.pipe(stream);
});

app.listen(3000, () => {
  console.log('Server started on port 3000');
});