Javascript 如何从节点获取调用中获取原始文件数据？

假设我有一个端点，比如

https://someurl.com/myfile.mp4

。我想获取mp4文件并将其原始数据插入字符串中，以便计算整个文件内容的sha256。如何使用节点获取库执行此操作？我在internet上找到的所有示例都假设从查询返回json对象，是否总是这样，我应该使用另一个库？下面是一个示例代码：

let urlFinal = 'https://someurl.com/myfile.mp4';
let videoFile = await fetch(urlFinal, {method: 'GET'}).then(res => { return res.blob() });
console.log('videofile: ' + videoFile) // prints out: videofile: [object Blob]
console.log('videofile: ' + JSON.stringify(videoFile)) // prints out: videofile: {}
calculateHash(videoFile)

---

我也没有在中找到关于

blob（）

函数和对象的任何信息。那么，在这种情况下，获取文件数据的最简单方法是什么？提前感谢

在内存中下载视频原始内容，如下所示：

const downloadNew = () => {
    http.get(urlFinal, (res) => {
        const { statusCode } = res;
        const contentType = res.headers['content-type'];

        let error;
        if (statusCode !== 200) {
            error = new Error('Request Failed.\n' +
                `Status Code: ${statusCode}`);
        } 
        
        if (error) {
            console.error(error.message);
            res.resume();
            return;
        }

        res.setEncoding('utf8');
        let rawData = '';
        res.on('data', (chunk) => { rawData += chunk; });
        res.on('end', () => {
            try {
                console.log(rawData);
            } catch (e) {
                console.error(e.message);
            }
        });
    }).on('error', (e) => {
        console.error(`Got error: ${e.message}`);
    });
}

const http = require('http');
const fs = require('fs');
const urlFinal = 'http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4';
const util = require("util");
const fetch = require("node-fetch");
const newFilePath = "/home/amulyakashyap/Desktop/download/BigBuckBunny.mp4";

const downloadUsingFetch => ()=>{
  fetch(urlFinal)
      .then(res => {
          const dest = fs.createWriteStream(newFilePath);
          res.body.pipe(dest);
      }).then(()=>console.log("finished"))
      .catch(console.error);
  }

const downloadUsingNative = function(cb) {
  let file = fs.createWriteStream(newFilePath);
  let request = http.get(urlFinal, function(response) {
    response.pipe(file);
    file.on('finish', function() {
     console.log("done")
      file.close(cb);

    });
  }).on('error', function(err) {
    fs.unlink(dest);
    if (cb) cb(err.message);
  });
};

const downloadUsingNativePromisified = util.promisify(downloadUsingNative);

downloadUsingNativePromisified().then(console.log).catch(console.error);

您可以使用nodefetch以及nodejs本机代码来实现这一点。我将演示在Nodejs中下载内容的两种方法（使用/不使用第三方Libs）：

使用节点获取库下载：

const downloadNew = () => {
    http.get(urlFinal, (res) => {
        const { statusCode } = res;
        const contentType = res.headers['content-type'];

        let error;
        if (statusCode !== 200) {
            error = new Error('Request Failed.\n' +
                `Status Code: ${statusCode}`);
        } 
        
        if (error) {
            console.error(error.message);
            res.resume();
            return;
        }

        res.setEncoding('utf8');
        let rawData = '';
        res.on('data', (chunk) => { rawData += chunk; });
        res.on('end', () => {
            try {
                console.log(rawData);
            } catch (e) {
                console.error(e.message);
            }
        });
    }).on('error', (e) => {
        console.error(`Got error: ${e.message}`);
    });
}

const http = require('http');
const fs = require('fs');
const urlFinal = 'http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4';
const util = require("util");
const fetch = require("node-fetch");
const newFilePath = "/home/amulyakashyap/Desktop/download/BigBuckBunny.mp4";

const downloadUsingFetch => ()=>{
  fetch(urlFinal)
      .then(res => {
          const dest = fs.createWriteStream(newFilePath);
          res.body.pipe(dest);
      }).then(()=>console.log("finished"))
      .catch(console.error);
  }

const downloadUsingNative = function(cb) {
  let file = fs.createWriteStream(newFilePath);
  let request = http.get(urlFinal, function(response) {
    response.pipe(file);
    file.on('finish', function() {
     console.log("done")
      file.close(cb);

    });
  }).on('error', function(err) {
    fs.unlink(dest);
    if (cb) cb(err.message);
  });
};

const downloadUsingNativePromisified = util.promisify(downloadUsingNative);

downloadUsingNativePromisified().then(console.log).catch(console.error);

使用本机Nodejs下载（不支持第三方Lib）：

const downloadNew = () => {
    http.get(urlFinal, (res) => {
        const { statusCode } = res;
        const contentType = res.headers['content-type'];

        let error;
        if (statusCode !== 200) {
            error = new Error('Request Failed.\n' +
                `Status Code: ${statusCode}`);
        } 
        
        if (error) {
            console.error(error.message);
            res.resume();
            return;
        }

        res.setEncoding('utf8');
        let rawData = '';
        res.on('data', (chunk) => { rawData += chunk; });
        res.on('end', () => {
            try {
                console.log(rawData);
            } catch (e) {
                console.error(e.message);
            }
        });
    }).on('error', (e) => {
        console.error(`Got error: ${e.message}`);
    });
}

const http = require('http');
const fs = require('fs');
const urlFinal = 'http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4';
const util = require("util");
const fetch = require("node-fetch");
const newFilePath = "/home/amulyakashyap/Desktop/download/BigBuckBunny.mp4";

const downloadUsingFetch => ()=>{
  fetch(urlFinal)
      .then(res => {
          const dest = fs.createWriteStream(newFilePath);
          res.body.pipe(dest);
      }).then(()=>console.log("finished"))
      .catch(console.error);
  }

const downloadUsingNative = function(cb) {
  let file = fs.createWriteStream(newFilePath);
  let request = http.get(urlFinal, function(response) {
    response.pipe(file);
    file.on('finish', function() {
     console.log("done")
      file.close(cb);

    });
  }).on('error', function(err) {
    fs.unlink(dest);
    if (cb) cb(err.message);
  });
};

const downloadUsingNativePromisified = util.promisify(downloadUsingNative);

downloadUsingNativePromisified().then(console.log).catch(console.error);

---

如果对你有用的话。请将答案向上投票。

但我不需要将文件写入磁盘，我只需要将其数据作为字符串存储在内存中。这不是我不需要用

fs

创建文件的另一种方法吗？@Fabiotk我已经更新了答案，请检查答案中的第一种方法。我希望它对你有用。另请参阅此链接：