plus.downloader.createDownload 发送 POST 请求并携带 token

 

 

/**
 * 创建下载任务
 * @param {string} url - 下载地址
 * @param {Object} params - POST参数
 * @param {Object} [options] - 下载配置选项
 * @returns {Promise} 下载结果Promise
 */
export const createPostDownload = (url, params, options = {}) => {
	return new Promise((resolve, reject) => {
		try {
			// 默认配置
			const defaultOptions = {
				method: 'POST',
				filename: '_downloads/',
				timeout: 120,
				retry: 1,
				...options
			}

			const headers = {
				'Content-Type': 'application/json',
				Accept: '*/*',
				...options.headers
			}

			console.log('开始下载，参数：', {
				url,
				params,
				headers
			})

			// 创建下载任务
			const downloadTask = plus.downloader.createDownload(
				url,
				{
					...defaultOptions,
					// 使用数组形式设置请求头
					headers,
					data: JSON.stringify(params)
				},
				(download, status) => {
					console.log('下载完成回调：', status, download)
					if (status === 200) {
						resolve({
							status,
							filename: download.filename,
							totalSize: download.totalSize,
							downloadedSize: download.downloadedSize
						})
					} else {
						reject(
							new Error(`Download failed with status: ${status}`)
						)
					}
				}
			)
			// 设置请求头
			for (const name in headers) {
				downloadTask.setRequestHeader(name, headers[name])
			}
			// 监听状态变化
			downloadTask.addEventListener('statechanged', (task, status) => {
				console.log('状态变化：', {
					status,
					state: task.state,
					downloadedSize: task.downloadedSize,
					totalSize: task.totalSize
				})

				// 处理不同的下载状态
				switch (task.state) {
					case 1: // 开始
						console.log('开始下载')
						break
					case 2: // 下载中
						handleProgress(task)
						break
					case 3: // 完成
						console.log('下载完成')
						break
					case 4: // 暂停
						console.log('下载暂停')
						break
					case -1: // 错误
						handleError(task)
						break
				}
			})

			// 处理进度
			const handleProgress = (task) => {
				if (typeof options.onProgress === 'function') {
					const progress =
						task.totalSize > 0
							? Math.floor(
									(task.downloadedSize / task.totalSize) * 100
							  )
							: 0

					options.onProgress({
						progress: Math.min(100, Math.max(0, progress)),
						downloadedSize: task.downloadedSize,
						totalSize: task.totalSize,
						state: task.state
					})
				}
			}

			// 处理错误
			const handleError = (task) => {
				console.error('下载错误：', task)
				reject(new Error('Download failed'))

				// 可以尝试重新下载
				if (defaultOptions.retry > 0) {
					console.log('尝试重新下载...')
					defaultOptions.retry--
					task.abort()
					setTimeout(() => {
						task.start()
					}, 1000)
				}
			}

			// 设置超时
			const timeout = setTimeout(() => {
				console.log('下载超时')
				downloadTask.abort()
				reject(new Error('Download timeout'))
			}, defaultOptions.timeout * 1000)

			// 开始下载
			console.log('启动下载任务')
			downloadTask.start()
			// downloadTask.sendData(JSON.stringify(params))
		} catch (error) {
			console.error('下载过程出错：', error)
			reject(error)
		}
	})
}

使用实例

 

// 使用示例
const downloadFile = async () => {
    try {
      const url = 'https://api.example.com/download';
      const params = {
        fileId: '123'
      };
  
      await createPostDownload(url, params, {
        filename: '_downloads/myfile.pdf',
        onProgress: (info) => {
          if (info.indeterminate) {
            console.log(`正在下载...已下载: ${info.downloadedSize} bytes`);
          } else {
            console.log(`下载进度：${info.progress}%`);
            console.log(`已下载：${info.downloadedSize} / ${info.totalSize} bytes`);
          }
  
          // 根据状态显示不同信息
          switch(info.state) {
            case 1:
              console.log('开始下载');
              break;
            case 2:
              console.log('正在下载');
              break;
            case 3:
              console.log('下载完成');
              break;
            case 4:
              console.log('下载暂停');
              break;
          }
        }
      });
  
      console.log('下载成功');
    } catch (error) {
      console.error('下载失败：', error);
    }
  };
  
  // 带进度条的UI示例
  const downloadWithProgressBar = async () => {
    const progressBar = document.querySelector('.progress-bar');
    const progressText = document.querySelector('.progress-text');
  
    try {
      await createPostDownload(url, params, {
        filename: '_downloads/myfile.pdf',
        onProgress: (info) => {
          if (!info.indeterminate) {
            // 更新进度条
            progressBar.style.width = `${info.progress}%`;
            progressText.textContent = `${info.progress}%`;
  
            // 添加下载速度计算
            const speed = calculateSpeed(info.downloadedSize, Date.now());
            const speedText = formatSpeed(speed);
  
            progressText.textContent =
              `${info.progress}% - ${speedText}`;
          } else {
            progressText.textContent = '准备下载...';
          }
        }
      });
    } catch (error) {
      progressText.textContent = '下载失败';
      console.error(error);
    }
  };
  
  // 下载速度计算辅助函数
  let lastSize = 0;
  let lastTime = Date.now();
  
  function calculateSpeed(currentSize, currentTime) {
    const sizeDiff = currentSize - lastSize;
    const timeDiff = currentTime - lastTime;
  
    lastSize = currentSize;
    lastTime = currentTime;
  
    return timeDiff > 0 ? (sizeDiff / timeDiff) * 1000 : 0; // bytes per second
  }
  
  function formatSpeed(bytesPerSecond) {
    if (bytesPerSecond < 1024) return `${bytesPerSecond.toFixed(1)} B/s`;
    if (bytesPerSecond < 1024 * 1024) return `${(bytesPerSecond / 1024).toFixed(1)} KB/s`;
    return `${(bytesPerSecond / (1024 * 1024)).toFixed(1)} MB/s`;
  }