前端技术前沿7

达达前端

发布于 2019-07-03 10:37:35

4870

发布于 2019-07-03 10:37:35

//加载一个http模块

var http = require('http');

//creatServer来创建WEB服务器名为server

var server= http.createServer(function(req,res){//函数的两个参数分别为req和res，作用分别是请求和响应

res.writeHead(200,{'content-Type':'text/pain'});//返回的请求头上写状态码是200，返回的文本内容的类型是纯文本

res.end('Hellow Nodejs\n');

});

server.listen(1337, '127.0.0.1');//listen在1337端口监听请求，服务器就可以收到任何来自端口的请求 

console.log('Server running at http://127.0.0.1:1337/');

var http = require("http");

http.crateServer(function(request, response) {
    response.writeHead(200, {"Content-Type": "text/plain"});
    response.write("Hello World");
    response.end();
}).listen(8888);

var http = require("http");
function onRequest(request, response) {
    response.writeHead(200, {"Content-Type": "text/plain"});
    response.write("Hello World");
    response.end();
}
http.createServer(onRequest).listen(8888);

//加载一个http模块

var http = require('http');

//creatServer来创建WEB服务器名为server

var server= http.createServer(function(req,res){//函数的两个参数分别为req和res，作用分别是请求和响应

res.writeHead(200,{'content-Type':'text/pain'});//返回的请求头上写状态码是200，返回的文本内容的类型是纯文本

res.end('Hellow Nodejs\n');

});

server.listen(1337, '127.0.0.1');//listen在1337端口监听请求，服务器就可以收到任何来自端口的请求 

console.log('Server running at http://127.0.0.1:1337/');

服务器是如何处理请求的

使用response.writeHead()函数发送一个HTTP状态200和HTTP头的内容类型content-type，使用response.write()函数在HTTP相应主体中发送文本。

调用response.end()完成响应

var http = require("http");
http.createServer(...);

请求服务器模块的脚本仅仅需要启动服务器而已。

var http = require("http");

function start() {
 function onRequest(request, response) {
  console.log("Request received");
  response.writeHead(200, {"Context-Type": "text/plain"});
  response.write("Hello World");
  response.end();
 }
 http.createServer(onRequest).listen(8888);
 console.log("Server has started");
}
exports.start = start;

var server = require("./server");
server.start();

路由选择 onRequest()回调函数的第一个参数传递 url和 querystring模块

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var http = require("http");
var url = require("url");
function start() {
function onRequest(request, response) {
var pathname = url.parse(request.url).pathname;
console.log("Request for " + pathname + " received.");
response.writeHead(200, {"Content-Type": "text/plain"});
response.write("Hello World");
response.end();
}
http.createServer(onRequest).listen(8888);
console.log("Server has started.");
}
exports.start = start;

function route(pathname) {
console.log("About to route a request for " + pathname);
}
exports.route = route;

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requestHandler.js修改

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function start(response) {
console.log("Request handler 'start' was called.");
var body = '<html>'+
'<head>'+
'<meta http-equiv="Content-Type" content="text/html; '+
'charset=UTF-8" />'+
'</head>'+
'<body>'+
'<form action="/upload" method="post">'+
'<textarea name="text" rows="20" cols="60"></textarea>'+
'<input type="submit" value="Submit text" />'+
'</form>'+
'</body>'+
'</html>';
response.writeHead(200, {"Content-Type": "text/html"});
response.write(body);
response.end();
}
function upload(response) {
console.log("Request handler 'upload' was called.");
response.writeHead(200, {"Content-Type": "text/plain"});
response.write("Hello Upload");
response.end();
}
exports.start = start;
exports.upload = upload;

如下所示：
request.addListener("data", function(chunk) {
// called when a new chunk of data was received
});
request.addListener("end", function() {
// called when all chunks of data have been received
});

先从 server.js开始：
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 + " received.");
request.setEncoding("utf8");
request.addListener("data", function(postDataChunk) {
postData += postDataChunk;
console.log("Received POST data chunk '"+
postDataChunk + "'.");
});
request.addListener("end", function() {
route(handle, pathname, response, postData);
});
}
http.createServer(onRequest).listen(8888);
console.log("Server has started.");
}
exports.start = start;

function route(handle, pathname, response, postData) {
console.log("About to route a request for " + pathname);
if (typeof handle[pathname] === 'function') {
handle[pathname](response, postData);
} else {
console.log("No request handler found for " + pathname);
response.writeHead(404, {"Content-Type": "text/plain"});
response.write("404 Not found");
response.end();
}
}
exports.route = route;

在 requestHandlers.js中，我们将数据包含在对 upload请求的响应中：

function start(response, postData) {
console.log("Request handler 'start' was called.");
var body = '<html>'+
'<head>'+
'<meta http-equiv="Content-Type" content="text/html; '+
'charset=UTF-8" />'+
'</head>'+
'<body>'+
'<form action="/upload" method="post">'+
'<textarea name="text" rows="20" cols="60"></textarea>'+
'<input type="submit" value="Submit text" />'+
'</form>'+
'</body>'+
'</html>';
response.writeHead(200, {"Content-Type": "text/html"});
response.write(body);
response.end();
}
function upload(response, postData) {
console.log("Request handler 'upload' was called.");
response.writeHead(200, {"Content-Type": "text/plain"});
response.write("You've sent: " + postData);
response.end();
}
exports.start = start;
exports.upload = upload;

querystring模块来实现：

var querystring = require("querystring");
function start(response, postData) {
console.log("Request handler 'start' was called.");
构建应用的模块 33
var body = '<html>'+
'<head>'+
'<meta http-equiv="Content-Type" content="text/html; '+
'charset=UTF-8" />'+
'</head>'+
'<body>'+
'<form action="/upload" method="post">'+
'<textarea name="text" rows="20" cols="60"></textarea>'+
'<input type="submit" value="Submit text" />'+
'</form>'+
'</body>'+
'</html>';
response.writeHead(200, {"Content-Type": "text/html"});
response.write(body);
response.end();
}
function upload(response, postData) {
console.log("Request handler 'upload' was called.");
response.writeHead(200, {"Content-Type": "text/plain"});
response.write("You've sent the text: "+
querystring.parse(postData).text);
response.end();
}
exports.start = start;
exports.upload = upload;

处理文件上传

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node-formidable 官方的例子展示了这两部分是如何融合在一起工作的：
var formidable = require('formidable'),
http = require('http'),
sys = require('sys');
http.createServer(function(req, res) {
if (req.url == '/upload' && req.method.toLowerCase() == 'post') {
// parse a file upload
var form = new formidable.IncomingForm();
form.parse(req, function(err, fields, files) {
res.writeHead(200, {'content-type': 'text/plain'});
res.write('received upload:\n\n');
res.end(sys.inspect({fields: fields, files: files}));
});
return;
}
// show a file upload form
res.writeHead(200, {'content-type': 'text/html'});
res.end(
'<form action="/upload" enctype="multipart/form-data" '+
'method="post">'+
'<input type="text" name="title"><br>'+
'<input type="file" name="upload" multiple="multiple"><br>'+
'<input type="submit" value="Upload">'+
'</form>'
);
}).listen(8888);