HarmonyNext使用request.agent.download實現斷點下載

filedownlaod(API12)

📚簡介

filedownload 這是一款支持大文件斷點下載的開源插件，退出應用程序進程殺掉以后或無網絡情況下恢復網絡后，可以在上次位置繼續恢復下載等

版本更新—請查看更新日志!!! 修復已知bug,demo已經更新

📚下載安裝

ohpm install @ohos_lib/filedownload

1、添加權限在應用主模塊entry/src/main/ets/module.json5下

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

2、在應用主模塊entry入口EntryAbility onCreate生命周期里下面添加初始化數據庫操作

 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、在應用主模塊entry入口Index.ts AboutToAppear()生命周期里添加如下代碼

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

4.首先確定服務器是否支持斷點下載，否則通過request.agent.create無法實現斷點下載

 curl -I -H "Range: bytes=0-100" 下載路徑

出現206 Partial Content 就代表著服務器支持斷點續傳與下載 —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相關 API

方法	介紹
persistActiveDownloads()	斷點下載的主要方法「內置更改數據庫狀態，把斷點前后字節數統一合并成一個文件」
static async pause(taskId: string):Promise	下載暫停方法「內置更改數據庫狀態」
static async resume(downloadInfo: IFileDownloader):Promise	下載恢復方法「內置更改數據庫狀態」
static async delete(userId: string, downloadId: string):Promise	刪除「取消下載」方法「刪除數據庫表記錄，刪除文件系統下載文件、」
static async downloadFile(data: T, isBatchInsertQueue?: boolean)	通用下載方法
GTNetworkUtil	網絡相關工具類「監聽有網、無網狀態」
FileUtil	文件操作相關工具類「沙盒文件存儲、刪除等操作」
SqliteHelper	數據庫操作類、「增刪改查」
static addListener(eventName:string,callback:(download:IFileDownloader)=>void)	下載統一監聽回調類「進度監聽、失敗、恢復、成功、暫停」

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';//登錄用戶信息id 這里寫四Mockprivate networkCallback:NetworkCallback={netAvailableCallback: (netHandle: ESObject) => {promptAction.showToast({message:'網絡可用~'})},netLostCallback: (_: ESObject) => {promptAction.showToast({message:'網絡連接已斷開，請檢查~'})//無網絡情況下，恢復網絡后繼續保持在上次位置下載 --只需要調用如下一行代碼即可// 本質邏輯內部還是發送了一個監聽，統一在DownloadManager.addListener監聽處理DownloaderUtil.persistActiveDownloads()}}@Local data: IResponseData[] = [];async aboutToAppear() {this.loadData();getContext().eventHub.on('reQuery',()=>{this.loadData();})DownloadManager.addListener(DownloadManager.eventName,(downloadInfo:IFileDownloader)=>{console.log('更新回調',downloadInfo.downloadSize)//進度監聽更新回調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;})//完善在無網絡情況下，下載任務暫停，并且恢復網絡后繼續下載GTNetworkUtil.register(this.networkCallback)}//TODO tips: 下載失敗，首先檢查url是否可以正常訪問，或者瀏覽器是否可以正常在線下載async loadData(){// TODO 假設從網絡獲取數據數據結構為: response=[{classNumber:'76432121445578293',className:'第一章 第一講：At the Airport在機場'}]//轉換數據結構response時接口類型必須要繼承 extends IFileDownloader IFileDownloader接口類型初始化至少包含三個字段userId ,downloadId,url userId登錄用戶的userId//因此extends IFileDownloader過的IResponseData接口類型 對應轉換后的數據如下所示let result:IResponseData[] =[{classNumber:'76432121445578293',downloadId:'76432121445578293',className:'第一章 第一講：At the Airport在機場',"url": "http://dal-video.wenzaizhibo.com/13c7d34a1181dddad67cfbe387977842/6836c525/00-x-upload/video/209245033_3aaf16a38aff214594fffec92839d37e_n8kGbGC8.mp4",       userId:this.userId}]//從數據庫讀取獲取上次的下載進度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 '下載完成'case DownloadStatus.PAUSE:return '暫停'case DownloadStatus.FAILED:return '下載失敗'case DownloadStatus.RUNNING:return '下載中'default :return '下載'}}@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) { //下載中---->點擊觸發取消下載【刪除下載】let number =  await DownloaderUtil.delete(item.userId,item.downloadId);if(number>0){this.loadData();}} else if (item?.status === DownloadStatus.FAILED) { //下載失敗----> 重新下載DownloaderUtil.downloadFile(item);} else if (item?.status === DownloadStatus.PAUSE) { //下載暫停----->代表要恢復下載await DownloaderUtil.resume(item);} else if(item.status===DownloadStatus.COMPLETED) { //下載完成 ---->去播放router.pushUrl({url: 'pages/VideoPlayerPage',params:{url:'file:///'+item.filePath+'/'+item.fileName,}})}else{ //未下載 -->去下載promptAction.showToast({message:'開始下載',})DownloaderUtil.downloadFile(item);}}).padding({left: 16,right: 16}).margin({top: 32})})}.layoutWeight(1)Button('查看下載').type(ButtonType.Capsule).onClick(()=>{router.pushUrl({url:'pages/DownloadManagerPage',params:{data:this.data,userId:this.userId}})}).backgroundColor(Color.Red)}.height('100%').width('100%')}
}