在node.js中出现奇怪的行为
我正在阅读http://www.nodebeginner.org上的教程,在数据输出中我有一个奇怪的行为。 我知道,在Stackoverflow上有类似的问题,但没有答案。 所以我有这个网络服务器的代码:
//server.js var http = require('http') var url = require('url') function start(route, handle) { function onRequest(request, response) { var postData = "" var pathname = url.parse(request.url).pathname console.log("Request for " + pathname + " recieved.") request.setEncoding('utf8') request.addListener("data", function(postDataChunk) { postData += postDataChunk console.log("Recieved POST data chunk '" + postDataChunk +"'.") }) request.addListener("end", function() { route(handle, pathname, response, postData) }) var content = route(handle, pathname, response) } http.createServer(onRequest).listen(80, '192.168.1.34') console.log("Server has started") } exports.start = start
调用requestHandler.upload的router.js代码 - 我的越野车功能
//router.js function route(handle, pathname, response, postData) { console.log("About to route a request for " + pathname) if (typeof handle[pathname] === 'function') { handle[pathname](response, postData) //calls requestHandler.upload } else { console.log("No request handler found for " + pathname) response.writeHead(404, {'Content-Type' : 'text/plain'}) response.write("404 Not found") response.end() } }
和requestHandler.upload的代码
//requestHandler.js function upload(response, postData) { console.log("Request handler 'upload' was called with POST data: " + postData); //works fine response.writeHead(200, {"Content-Type": "text/plain"}); response.write("You've sent: " + postData); //works ugly response.end(); }
假设在POST数据中有一个字符串text=123
。 这个函数的第一行输出真正的数据,如"Request handler 'upload' was called with POST data: text=123"
。 虽然,这行response.write("You've sent: " + postData);
在浏览器中输出下一条消息: You've sent: undefined
。 我究竟做错了什么?
在server.js
的代码行中:
var content = route(handle, pathname, response)
在"end"
事件侦听器中调用之前正在运行,执行该函数但省略postData
参数。 它运行...
response.write("You've sent: " + postData);
response.end();
因此,发送回浏览器的响应是:
You've sent: undefined
之后会触发"end"
事件,并且事件侦听器会调用...
route(handle, pathname, response, postData)
哪些正确传递postData
,并将其正确输出到控制台。 对response.write(...)
的调用不会第二次回发给浏览器,因为此时的响应已经结束。
我希望能解释这个问题。
编辑答案是删除电话
var content = route(handle, pathname, response)
当客户完成发布数据并且您在该点正确运行route
功能时,将会调用"end"
事件。
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