通过请求获取Node.js格式的下载进度
通过请求获取Node.js格式的下载进度
提问于 2013-08-20 05:08:06
我正在创建一个使用Node模块request下载应用程序文件的更新程序。如何使用chunk.length估计剩余的文件大小？下面是我的部分代码：
var file_url = 'http://foo.com/bar.zip';
var out = fs.createWriteStream('baz.zip');
var req = request({
method: 'GET',
uri: file_url
});
req.pipe(out);
req.on('data', function (chunk) {
console.log(chunk.length);
});
req.on('end', function() {
//Do something
});回答 6
Stack Overflow用户
回答已采纳
发布于 2013-08-20 06:28:59
这应该会让你得到你想要的总数：
req.on( 'response', function ( data ) {
console.log( data.headers[ 'content-length' ] );
} );我得到的内容长度是9404541
Stack Overflow用户
发布于 2013-11-26 04:51:44
function download(url, callback, encoding){
var request = http.get(url, function(response) {
if (encoding){
response.setEncoding(encoding);
}
var len = parseInt(response.headers['content-length'], 10);
var body = "";
var cur = 0;
var obj = document.getElementById('js-progress');
var total = len / 1048576; //1048576 - bytes in 1Megabyte
response.on("data", function(chunk) {
body += chunk;
cur += chunk.length;
obj.innerHTML = "Downloading " + (100.0 * cur / len).toFixed(2) + "% " + (cur / 1048576).toFixed(2) + " mb\r" + ".<br/> Total size: " + total.toFixed(2) + " mb";
});
response.on("end", function() {
callback(body);
obj.innerHTML = "Downloading complete";
});
request.on("error", function(e){
console.log("Error: " + e.message);
});
});
};Stack Overflow用户
发布于 2017-02-16 19:47:17
如果您使用的是request模块，并且希望在不使用任何额外模块的情况下显示下载百分比，您可以使用以下代码：
function getInstallerFile (installerfileURL,installerfilename) {
// Variable to save downloading progress
var received_bytes = 0;
var total_bytes = 0;
var outStream = fs.createWriteStream(installerfilename);
request
.get(installerfileURL)
.on('error', function(err) {
console.log(err);
})
.on('response', function(data) {
total_bytes = parseInt(data.headers['content-length']);
})
.on('data', function(chunk) {
received_bytes += chunk.length;
showDownloadingProgress(received_bytes, total_bytes);
})
.pipe(outStream);
};
function showDownloadingProgress(received, total) {
var platform = "win32"; // Form windows system use win32 for else leave it empty
var percentage = ((received * 100) / total).toFixed(2);
process.stdout.write((platform == 'win32') ? "\033[0G": "\r");
process.stdout.write(percentage + "% | " + received + " bytes downloaded out of " + total + " bytes.");
}用法：
getInstallerFile("http://example.com/bar.zip","bar.zip");页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/18323152
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