HarmonyNext使用request.agent.download实现断点下载

filedownlaod(API12)

📚简介

filedownload 这是一款支持大文件断点下载的开源插件，退出应用程序进程杀掉以后或无网络情况下恢复网络后，可以在上次位置继续恢复下载等

版本更新—请查看更新日志!!! 修复已知bug,demo已经更新

📚下载安装

ohpm install @ohos_lib/filedownload

1、添加权限在应用主模块entry/src/main/ets/module.json5下

"requestPermissions": [{"name" : "ohos.permission.INTERNET"},{"name" : "ohos.permission.GET_NETWORK_INFO"},]

2、在应用主模块entry入口EntryAbility onCreate生命周期里下面添加初始化数据库操作

 onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {this.context.getApplicationContext().setColorMode(ConfigurationConstant.ColorMode.COLOR_MODE_NOT_SET);hilog.info(DOMAIN, 'testTag', '%{public}s', 'Ability onCreate');SqliteHelper.getInstance(this.context).initRDB();
}

3、在应用主模块entry入口Index.ts AboutToAppear()生命周期里添加如下代码

 try {await DownloaderUtil.persistActiveDownloads();
}catch (e) {
}

4.首先确定服务器是否支持断点下载，否则通过request.agent.create无法实现断点下载

 curl -I -H "Range: bytes=0-100" 下载路径

出现206 Partial Content 就代表着服务器支持断点续传与下载 —如下

yanruifeng@bogon video % curl -I -H "Range: bytes=0-100" https://dal-video.wenzaizhibo.com/a6dac8c6371a54477a5692f46ea9698e/6825c7da/00-x-upload/video/205971345_ae77bc38ae8b689a5a534e51b3153c8b_Kg3W8sai.mp4HTTP/1.1 206 Partial Content

filedownload相关 API

方法	介绍
persistActiveDownloads()	断点下载的主要方法「内置更改数据库状态，把断点前后字节数统一合并成一个文件」
static async pause(taskId: string):Promise	下载暂停方法「内置更改数据库状态」
static async resume(downloadInfo: IFileDownloader):Promise	下载恢复方法「内置更改数据库状态」
static async delete(userId: string, downloadId: string):Promise	删除「取消下载」方法「删除数据库表记录，删除文件系统下载文件、」
static async downloadFile(data: T, isBatchInsertQueue?: boolean)	通用下载方法
GTNetworkUtil	网络相关工具类「监听有网、无网状态」
FileUtil	文件操作相关工具类「沙盒文件存储、删除等操作」
SqliteHelper	数据库操作类、「增删改查」
static addListener(eventName:string,callback:(download:IFileDownloader)=>void)	下载统一监听回调类「进度监听、失败、恢复、成功、暂停」

基本用法

import { IFileDownloader } from '@ohos_lib/filedownload/src/main/ets/interface/IFileDownloader';
import {DownloaderUtil,DownloadManager, NetworkCallback, SqliteHelper,GTNetworkUtil} from '@ohos_lib/filedownload'
import { DownloadStatus } from '@ohos_lib/filedownload/src/main/ets/constants/DownloadStatus';
import { relationalStore } from '@kit.ArkData';
import { promptAction, router } from '@kit.ArkUI';
import { IResponseData } from '../interfaces/IResponseData';@Entry
@ComponentV2
struct SingleFileDownload {@Local userId:string ='722134343434343434';//登录用户信息id 这里写四Mockprivate networkCallback:NetworkCallback={netAvailableCallback: (netHandle: ESObject) => {promptAction.showToast({message:'网络可用~'})},netLostCallback: (_: ESObject) => {promptAction.showToast({message:'网络连接已断开，请检查~'})//无网络情况下，恢复网络后继续保持在上次位置下载 --只需要调用如下一行代码即可// 本质逻辑内部还是发送了一个监听，统一在DownloadManager.addListener监听处理DownloaderUtil.persistActiveDownloads()}}@Local data: IResponseData[] = [];async aboutToAppear() {this.loadData();getContext().eventHub.on('reQuery',()=>{this.loadData();})DownloadManager.addListener(DownloadManager.eventName,(downloadInfo:IFileDownloader)=>{console.log('更新回调',downloadInfo.downloadSize)//进度监听更新回调let newData =  this.data?.map((item)=>{if(item.downloadId===downloadInfo.downloadId){item.taskId = downloadInfo.taskId;item.filePath = downloadInfo.filePath;item.fileName =downloadInfo.fileName;item.downloadSize = downloadInfo.downloadSize;item.fileSize = downloadInfo.fileSize;item.isBackgroundPause =downloadInfo.isBackgroundPause;item.exitFrequency = downloadInfo.exitFrequency;item.status = downloadInfo.status;item.begins = downloadInfo.begins;return item;}return item;})this.data =newData;})//完善在无网络情况下，下载任务暂停，并且恢复网络后继续下载GTNetworkUtil.register(this.networkCallback)}//TODO tips: 下载失败，首先检查url是否可以正常访问，或者浏览器是否可以正常在线下载async loadData(){// TODO 假设从网络获取数据数据结构为: response=[{classNumber:'76432121445578293',className:'第一章 第一讲：At the Airport在机场'}]//转换数据结构response时接口类型必须要继承 extends IFileDownloader IFileDownloader接口类型初始化至少包含三个字段userId ,downloadId,url userId登录用户的userId//因此extends IFileDownloader过的IResponseData接口类型 对应转换后的数据如下所示let result:IResponseData[] =[{classNumber:'76432121445578293',downloadId:'76432121445578293',className:'第一章 第一讲：At the Airport在机场',"url": "http://dal-video.wenzaizhibo.com/13c7d34a1181dddad67cfbe387977842/6836c525/00-x-upload/video/209245033_3aaf16a38aff214594fffec92839d37e_n8kGbGC8.mp4",       userId:this.userId}]//从数据库读取获取上次的下载进度let predicates =new relationalStore.RdbPredicates(SqliteHelper.tableName);predicates.equalTo('userId',this.userId);let queryList = await SqliteHelper.getInstance(getContext()).queryData(predicates);if(queryList.length>0){let newData = result.map((item:IResponseData)=>{let obj =queryList.find(el=>el.downloadId===item.downloadId);if(obj) {item.taskId = obj.taskId;item.filePath = obj.filePath;item.fileName =obj.fileName;item.downloadSize = obj.downloadSize;item.fileSize = obj.fileSize;item.isBackgroundPause =obj.isBackgroundPause;item.exitFrequency = obj.exitFrequency;item.status = obj.status;item.begins = obj.begins;return item;}return item;})this.data= newData;}else{this.data = result;}}aboutToDisappear(): void {GTNetworkUtil.unregister();DownloadManager.removeListener(DownloadManager.eventName)getContext().eventHub.off('reQuery');}getStatus(status:number|undefined){switch (status){case DownloadStatus.COMPLETED:return '下载完成'case DownloadStatus.PAUSE:return '暂停'case DownloadStatus.FAILED:return '下载失败'case DownloadStatus.RUNNING:return '下载中'default :return '下载'}}@Builder imageAnimator(item:IResponseData){ImageAnimator().images([{src: $r('app.media.ic_downloading_1')},{src: $r('app.media.ic_downloading_2')},{src: $r('app.media.ic_downloading_3')},{src: $r('app.media.ic_downloading_4')},{src: $r('app.media.ic_downloading_5')}]).duration(1000).state(item.status===DownloadStatus.RUNNING?AnimationStatus.Running:AnimationStatus.Initial).reverse(false).fillMode(FillMode.None).iterations(-1).width(24).height(24).onStart(() => {console.info('Start')}).onPause(() => {console.info('Pause')}).onRepeat(() => {console.info('Repeat')}).onCancel(() => {console.info('Cancel')}).onFinish(() => {console.info('Finish')})}build() {Column() {Stack({alignContent:Alignment.TopStart}){ForEach(this.data,(item:IResponseData)=>{Flex({direction:FlexDirection.Row,alignItems:ItemAlign.Center,justifyContent:FlexAlign.SpaceBetween}) {Row(){Text(item?.className).fontSize(16).fontWeight(FontWeight.Bold)}.layoutWeight(1)if(item.status===DownloadStatus.COMPLETED){Image($r('app.media.ic_download_completed')).width(24).height(24)}else if(item.status===DownloadStatus.RUNNING) {this.imageAnimator(item);}else if(item.status===DownloadStatus.FAILED){Image($r('app.media.ic_download_fail')).width(24).height(24)}else if(item.status===DownloadStatus.PAUSE){Image($r('app.media.ic_download_start')).width(24).height(24)}}.width('100%').height(44).onClick(async ()=>{if (item?.status === DownloadStatus.RUNNING) { //下载中---->点击触发取消下载【删除下载】let number =  await DownloaderUtil.delete(item.userId,item.downloadId);if(number>0){this.loadData();}} else if (item?.status === DownloadStatus.FAILED) { //下载失败----> 重新下载DownloaderUtil.downloadFile(item);} else if (item?.status === DownloadStatus.PAUSE) { //下载暂停----->代表要恢复下载await DownloaderUtil.resume(item);} else if(item.status===DownloadStatus.COMPLETED) { //下载完成 ---->去播放router.pushUrl({url: 'pages/VideoPlayerPage',params:{url:'file:///'+item.filePath+'/'+item.fileName,}})}else{ //未下载 -->去下载promptAction.showToast({message:'开始下载',})DownloaderUtil.downloadFile(item);}}).padding({left: 16,right: 16}).margin({top: 32})})}.layoutWeight(1)Button('查看下载').type(ButtonType.Capsule).onClick(()=>{router.pushUrl({url:'pages/DownloadManagerPage',params:{data:this.data,userId:this.userId}})}).backgroundColor(Color.Red)}.height('100%').width('100%')}
}