9

我在使用 Node.js 时遇到了一种奇怪的行为http.get。我使用 ajax 向 url 发出请求，并希望将结果输入我的浏览器。但我只得到一些<head>标签内容，仅此而已，没有<body>内容。但是，如果我将结果发送到系统控制台 ( console.log(chunk))，我会得到我想要的结果 - 整页。这是我的步骤：

// Simple jQuery Ajax GET
$.ajax({
    type: "GET",
    url: "/myapppath",   // send to my app's url
    data: {foo: "bar"},
    success: onLoad,    // the callback, see just bellow
    error: onError,
    dataType: "text"
});

// With this callback function I want to insert the result into <div id="baz">
function onLoad(resp) {
   document.getElementById("baz").innnerHTML = resp;
}

// In /myapppath
http.get("http://stackoverflow.com/", function(result) {
   result.setEncoding('utf8');
   result.on("data", function(chunk) {
      console.log(chunk); // this successfully returns the whole page but into system console
      res.end(chunk);   // this returns just a piece of <head> tag into the browser.
   });
});

所以在我的<div id="baz">我只得到一些请求标签，没有<head>标签及其内容。这就是我得到的所有内容，而不是整个页面：http://stackoverflow.com/<body><div id="baz">

<!DOCTYPE html>
<html>
<head> 
    <title>Stack Overflow</title>
    <link rel="shortcut icon" href="https://cdn.sstatic.net/stackoverflow/img/favicon.ico">
    <link rel="apple-touch-icon image_src" href="https://cdn.sstatic.net/stackoverflow/img/apple-touch-icon.png">
    <link rel="search" type="application/opensearchdescription+xml" title="Stack Overflow" href="/opensearch.xml">

    <script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
    <script type="text/javascript" src="https://cdn.sstatic.net/js/stub.js?v=dd6898efd655"></script>
    <link rel="stylesheet" type="text/css" href="https://cdn.sstatic.net/stackoverflow/all.css?v=8a5907e853ab">

    <link rel="alternate" type="application/atom+xml" title="Feed of recent questions" href="/feeds">
        <script type="text/javascript" defer>
        </script>    
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</h

但是，console.log(chunk)正如我上面所说，我在控制台中打印了整个页面。

到底是怎么回事？为什么http.get不向浏览器返回完整响应？我错过了什么？什么削减了反应？

4

2 回答 2

14

console.log(chunk);实际上并没有一次记录整个页面，但是chunk随着更多页面的'data'到来，它确实会继续记录每个页面。

res.end()另一方面，在第一次调用后关闭连接时变为无操作，因此仅chunk包括第一次。

你可以做的是res.write()每chunk一个，'data'等待：'end'res.end()

http.get("http://stackoverflow.com/", function (result) {
    result.on('data', function (chunk) {
        res.write(chunk);
    });
    result.on('end', function () {
        res.end();
    });
});

或者，因为result是Stream.Readable ( IncomingMessage) 并且res可能是Stream.Writable（猜测 a ServerResponse），你应该能够.pipe()：

http.get('http://stackoverflow.com', function (result) {
    result.pipe(res);
});
于 2013-07-25T17:40:12.747 回答
11

您的数据事件会触发多次，但您只能“结束”一次输出...您可能应该按如下方式重构您的处理程序... 

// In /myapppath
http.get("http://stackoverflow.com/", function(result) {
    var responseParts = [];
    result.setEncoding('utf8');
    result.on("data", function(chunk) {
        //add this chunk to the output to send
        responseParts.push(chunk);
    });
    result.on("end", function(){
        //now send your complete response
        res.end(responseParts.join(''));
    });
});
于 2013-07-25T17:27:56.810 回答