js 上传文件流

// 使用 XMLHttpRequest 显示上传进度
const xhr = new XMLHttpRequest();
xhr.upload.addEventListener('progress', (event) => {
  if (event.lengthComputable) {
    const percentComplete = (event.loaded / event.total) * 100;
    console.log(`Upload progress: ${percentComplete}%`);
  }
});
xhr.open('POST', '/upload');
xhr.send(file);

// 使用 Fetch API 显示上传进度（需要服务器支持）
async function uploadFile(file) {
  const response = await fetch('/upload', {
    method: 'POST',
    body: file,
  });
  const reader = response.body.getReader();
  const contentLength = response.headers.get('Content-Length');
  let receivedLength = 0;
  while (true) {
    const { done, value } = await reader.read();
    if (done) break;
    receivedLength += value.length;
    const percentComplete = (receivedLength / contentLength) * 100;
    console.log(`Upload progress: ${percentComplete}%`);
  }
}

try {
  const response = await fetch('/upload', {
    method: 'POST',
    body: file,
  });
  if (!response.ok) {
    throw new Error('Upload failed');
  }
  console.log('Upload successful');
} catch (error) {
  console.error('Error uploading file:', error);
}