【HarmonyOS NEXT】鸿蒙应用压缩和解压处理
一、前言
鸿蒙应用中经常会遇到使用压缩包的场景。例如H5的离线包逻辑，需要提前将资源包下载到本地，进行压缩操作获取资源。
二、方案思路
鸿蒙中提供@ohos.zlib (Zip模块)进行压缩和解压的处理。
需要注意的是，操作路径需要在沙箱中，那如果压缩包在项目工程资源文件夹中，需要提前对压缩包文件进行拷贝到沙箱路径的操作。
zlib.compressFile 进行压缩
zlib.decompressFile 进行解压
三、源码示例
import { zlib, BusinessError } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';
import { common } from '@kit.AbilityKit';
import { util } from '@kit.ArkTS';
import { buffer } from '@kit.ArkTS';
@Entry
@Component
struct ZipTestPage {
private TAG: string = "ZipTestPage";
@State mZipTestContent: string = "";
// 指定的待解压缩文件的文件路径，文件后缀需要以.zip结尾。文件路径必须为沙箱路径，沙箱路径可以通过context获取
private inFile = '/xx/xxx.zip';
// 指定的解压后的文件夹路径，文件夹目录路径需要在系统中存在，不存在则会解压失败。
// 路径必须为沙箱路径，沙箱路径可以通过context获取
// 如果待解压的文件或文件夹在解压后的路径下已经存在，则会直接覆盖同名文件或同名文件夹中的同名文件。多个线程同时解压文件时，outFile不能相同。
private outFileDir = '/xxx';
// 解压的配置参数。
private options: zlib.Options = {
// 压缩率 默认压缩等级。
level: zlib.CompressLevel.COMPRESS_LEVEL_DEFAULT_COMPRESSION
};
aboutToAppear(): void {
// 准备zip到沙箱路径下
this.copyRawFileToLocal();
// 填充待解压文件路径和解压后的文件路径
this.setting();
}
private setting(){
let pathDir: string = getContext().filesDir;
console.info(this.TAG, "setting pathDir: " + pathDir);
this.inFile = pathDir + '/test.zip';
console.info(this.TAG, "setting inFile: " + this.inFile);
this.outFileDir = pathDir;
console.info(this.TAG, "setting outFileDir: " + this.outFileDir);
}
/**
* 点击解压
*/
onUnZip = async ()=>{
try {
console.info(this.TAG, "onUnZip start");
// 解压文件，解压的结果回调
zlib.decompressFile(this.inFile, this.outFileDir, this.options, (errData: BusinessError) => {
if (errData !== null) {
console.error(this.TAG, `errData is errCode:${errData.code} message:${errData.message}`);
}
console.info(this.TAG, "onUnZip done");
// 解压成功后，则去输出的路径下outFileDir，读取文件
let fileTarget = fs.openSync(this.outFileDir + "/test.txt", fs.OpenMode.READ_ONLY);
let size = fs.statSync(fileTarget.fd).size;
console.info(this.TAG, "onUnZip size: " + size);
let bufferRes = new ArrayBuffer(size);
let readLen = fs.readSync(fileTarget.fd, bufferRes);
fs.closeSync(fileTarget);
console.info(this.TAG, "onUnZip readLen: " + readLen);
let decoder = util.TextDecoder.create('utf-8');
let temp = new Uint8Array(bufferRes);
let result = decoder.decodeToString(temp);
console.info(this.TAG, "onUnZip text: " + result);
this.mZipTestContent = result;
// let pathDir: string = getContext().filesDir;
// let filePath = pathDir + "/test.txt";
// let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE);
// let arrayBuffer = new ArrayBuffer(4096);
// fs.read(file.fd, arrayBuffer, (err: BusinessError, readLen: number) => {
// if (err) {
// console.error(this.TAG,"read failed with error message: " + err.message + ", error code: " + err.code);
// } else {
// console.info(this.TAG, "read file data succeed");
// let buf = buffer.from(arrayBuffer, 0, readLen);
// console.info(this.TAG, `The content of file: ${buf.toString()}`);
// }
// fs.closeSync(file);
// });
})
} catch (errData) {
let code = (errData as BusinessError).code;
let message = (errData as BusinessError).message;
console.error(this.TAG, `errData is errCode:${code} message:${message}`);
}
}
private copyRawFileToLocal() {
let context = getContext(this) as common.UIAbilityContext; // 获取设备A的UIAbilityContext信息
try {
let val: Uint8Array = context.resourceManager.getRawFileContentSync("test.zip");
console.info(this.TAG, "getRawFileContentSync done");
let pathDir: string = context.filesDir; // /data/storage/el2/base/haps/entry/files
console.info(this.TAG, "pathDir: " + pathDir);
// 待拷贝文件沙箱路径
let filePath: string = pathDir + '/test.zip';
console.info(this.TAG, "filePath: " + filePath);
// 若文件不存在，则创建文件。
let fileTarget = fs.openSync(filePath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
console.info(this.TAG, "file done");
let writeLen = fs.writeSync(fileTarget.fd, val.buffer as ArrayBuffer);
console.info(this.TAG, "write data to file succeed and size is:" + writeLen);
fs.closeSync(fileTarget);
} catch (error) {
let code = (error as BusinessError).code;
let message = (error as BusinessError).message;
console.error(this.TAG,`getRawFileContentSync failed, error code: ${code}, message: ${message}.`);
}
}
build() {
RelativeContainer() {
Text("点击解压，内容： " + this.mZipTestContent)
.id('ZipTestPageHelloWorld')
.fontSize(50)
.fontWeight(FontWeight.Bold)
.alignRules({
center: { anchor: '__container__', align: VerticalAlign.Center },
middle: { anchor: '__container__', align: HorizontalAlign.Center }
})
.onClick(this.onUnZip)
}
.height('100%')
.width('100%')
}
}