Nodejs http https模块get请求 管道下载 / 收集完转其他
import https from 'https'
import http from 'http'
const stream = fs.createWriteStream(path)
const httpName = this.fileUrl.includes('https') ? https : http
const request = httpName.get(
this.fileUrl,
{
headers: { }, // 可携带token
timeout: 0, // 0 不超时
rejectUnauthorized: false // 用于https证书
},
(res: any) => {
// 文件总长度
const len = parseInt(res.headers['content-length'])
let cur = 0
// 通过pipe管道写入
res.pipe(stream)
res.on('data', (chunk: any) => {
chunks.push(chunk)
cur += chunk.length
// 当前进度
const progress: number = Number(((100.0 * cur) / len).toFixed(2))
// 当前下载了多少M
// const currProgress = (cur / 1048576).toFixed(2)
// console.log('当前下载进度:' + progress)
})
// 下载结束 -> 后触发 stream.on('finish')
res.on('end', () => {
// 如果用了pipe，就不要用这个。 Buffer.concat(chunks).toString('base64')就可以转换为base64格式了
// stream.write(Buffer.concat(chunks))
// stream.end()
}
})
}
)
注意：如果需要对文件加解密就是对Buffer加解密，例如SM4对Buffer加解密
const sm4 = require('sm-crypto').sm4
export function stringToHex(str: string) {
const len: number = str.length
let val = ''
for (let i = 0; i < len; i++) {
val += '' + str.charCodeAt(i).toString(16)
}
return val
}
// 解密
const deChunk = sm4.decrypt(Buffer.concat(chunks), stringToHex(key), { output: 'array' })
new Blob([Buffer.from(deChunk)], { type: 'image/png' })
// 加密 （对buffer加密，加密后在转base64 或者 Blob）
const enChunk = sm4.encrypt(getBufferByFile(file), stringToHex(key), { output: 'array' })
blob -> new Blob([Buffer.from(enChunk)], { type: 'image/png' })
base64 -> Buffer.from(enChunk).toString('base64')
再调用接口上传
文件转Buffer(二进制)
const getBufferByFile = async (file: File | Blob): Promise<Buffer> => {
const arrayBuffer = await file.arrayBuffer()
return Buffer.from(arrayBuffer)
}
Buffer转Base64
Buffer.from(arrayBuffer).toString('base64')
base64转Blob
const base64ToBlob = (b64data: string, contentType: string, sliceSize = 512) => {
return new Promise((resolve) => {
// 使用 atob() 方法将数据解码
const byteCharacters = atob(b64data)
const byteArrays = []
for (let offset = 0; offset < byteCharacters.length; offset += sliceSize) {
const slice = byteCharacters.slice(offset, offset + sliceSize)
const byteNumbers = []
for (let i = 0; i < slice.length; i++) {
byteNumbers.push(slice.charCodeAt(i))
}
// 8 位无符号整数值的类型化数组。内容将初始化为 0。
// 如果无法分配请求数目的字节，则将引发异常。
byteArrays.push(new Uint8Array(byteNumbers))
}
let result = new Blob(byteArrays, {
type: contentType
})
result = Object.assign(result, {
// jartto: 这里一定要处理一下 URL.createObjectURL
preview: URL.createObjectURL(result),
name: `图片示例.png`
})
resolve(result)
})
}
blob转base64
const blobToBase64 = (blob: Blob | File): Promise<string> => {
return new Promise((resolve, reject) => {
const fileReader = new FileReader()
fileReader.onload = (e) => {
e.target ? resolve(e.target.result as string) : reject(new Error('文件流异常'))
}
fileReader.readAsDataURL(blob)
fileReader.onerror = () => {
reject(new Error('文件流异常'))
}
})
}
