import request from '@ohos.request';
import fs from '@ohos.file.fs';
import { BusinessError } from '@kit.BasicServicesKit';
import { common, Want } from '@kit.AbilityKit';export  class DownloadUtils{/*** 下载文件* @param mContext* @param url* @param destFileDir* @param fileName* @param callback*/public static downloadFile(mContext:Context,url: string, destFileDir: string, fileName: string ,callback: FileCallback): void{//  const filePath = mContext.filesDir + '/' + fileName;const filePath =   destFileDir + '/' + fileName;try {// 判定文件是否存在if (fs.accessSync(filePath)) {// 删除文件fs.unlinkSync(filePath)}let isHaveFile=fs.accessSync(destFileDir)if(!isHaveFile){fs.mkdirSync(destFileDir)}// 下载文件request.downloadFile(mContext, { url: url, filePath: filePath, enableMetered: true,enableRoaming: true }, (err, data) => {if (err) {console.error('Failed to request the download. Cause: ' + JSON.stringify(err));callback.onError()}// 监听文件下载的实时情况 receivedSize已下载 totalSize总大小data.on('progress', (receivedSize, totalSize) => {console.info("upload totalSize:" + totalSize + "  receivedSize:" + receivedSize);callback.inProgress(receivedSize,totalSize)})// 监听文件下载完成data.on('complete', () => {console.info('Download task completed.');callback.onSuccess(filePath)})});} catch (err) {console.error('err.code : ' + err.code + ', err.message : ' + err.message);callback.onError()}}}interface FileCallback {onError: () => void;inProgress: (progress: number, total: number) => void;onSuccess: (file: string) => void;
}

使用方法

let context = getContext(this) as common.UIAbilityContext;
let url="http://www.fao.fudan.edu.cn/_upload/article/files/f5/53/8b40af524563b9b60049899b2dd3/c9a205b4-4188-4af3-863e-bc4e56872e33.pdf"
const filePath = context.filesDir + '/' + "111.pdf";
DownloadUtils.downloadFile(context, url, filePath, "111.pdf", {onError: () => {console.error("下载失败");},inProgress: (progress, total) => {console.log(`下载进度：${progress}/${total}`);},onSuccess: (file) => {console.log(`下载成功，文件保存在: ${file}`);}
});