Node入门
本书最后实现了一个简易Node应用，对于入门Node的同学，理解模块、阻塞、事件驱动等概念有很大帮助。
server.js
var formidable = require("formidable");
var http = require("http");
var url = require("url");
function start(route,handler) {
function onRequest(req,res) {
var postData = "";
var pathname = url.parse(req.url).pathname;
console.log("Request for " + pathname + " received.");
if (pathname === "/favicon.ico") return;
route(handler,pathname,res,req);
}
http.createServer(onRequest).listen(8888);
console.log("Server has started for : http://localhost:8888");
}
exports.start = start;
router.js
function route(handle,pathname,res,req) {
console.log("About to route a request for " + pathname);
if (typeof handle[pathname] === "function") {
return handle[pathname](res,req);
} else {
console.log("Error! No request handler found for " + pathname);
}
}
exports.route = route;
reqHandlers.js
var querystring = require("querystring"),
fs = require("fs"),
formidable = require("formidable");
function start(res) {
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" enctype="multipart/form-data" ' +
'method="post">' +
'<input type="file" name="upload">' +
'<input type="submit" value="Upload file" />' +
'</form>' +
'</body>' +
'</html>';
res.writeHead(200,{"Content-Type":"text/html"});
res.write(body);
res.end();
}
function upload(res,req) {
console.log("Request handler 'upload' was called.");
// 可以试着打印req对象，查看如何解析的
var form = new formidable.IncomingForm();
console.log("form 正在解析 post");
form.parse(req,function(error,fields,files) {
console.log("解析完成");
// 重命名图片，确保show正确
console.log(files.upload.path);
fs.renameSync(files.upload.path, "./tmp/test.png");
res.writeHead(200, {"Content-Type": "text/html"});
res.write("received image:<br/>");
res.write("<img src='/show' />");
res.end();
})
}
function show(res) {
console.log("Request handler 'show' was called");
fs.readFile("./tmp/test.png","binary",function(error,file) {
if (error) {
res.writeHead(500, {"Content-Type": "text/plain"});
res.write(error + "\n");
res.end();
} else {
res.writeHead(200, {"Content-Type": "image/png"});
res.write(file, "binary");
res.end();
}
})
}
exports.start = start;
exports.upload = upload;
exports.show = show;
main.js
var server = require("./server");
var router = require("./router");
var reqhandlers = require("./reqHandlers");
var handler = {};
handler["/"] = reqhandlers.start;
handler["/start"] = reqhandlers.start;
handler["/upload"] = reqhandlers.upload;
handler["/show"] = reqhandlers.show;
server.start(router.route,handler);
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