上节我们把服务器、路由和请求处理程序结合在一起了，下面就编写一个具体的 web 应用。
上传图片的 web 应用
服务器模块（server.js）
var http = require('http'); var url = require('url'); function start(route, handler) { function onRequest(request, response) { var pathname = url.parse(request.url).pathname; console.log('Request ' + pathname + ' received.'); route(handler, pathname, response, request); } http.createServer(onRequest).listen(8888); console.log('Server has started.'); } exports.start = start;
路由模块（route.js）
function route(handler, pathname, response, request) { console.log('Route a request for ' + pathname); if (typeof handler[pathname] === 'function') { handler[pathname](response, request); } 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;
请求处理程序模块（requestHandlers.js）
var querystring = require('querystring'), fs = require('fs'), formidable = require('formidable'); // 如果 formidable 模块是全局安装，只能绝对路径调用，如果本地安装，require(formidable) 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" enctype="multipart/form-data" method="post">' + '<input type="file" name="upload">' + '<input type="submit" value="Upload file">' + '</form>' + '</body>' + '</html>'; response.writeHead(200, { 'Content-Type': 'text/html' }); response.write(body); response.end(); } function upload(response, request) { console.log('Request handler "upload" was called.'); var form = new formidable.IncomingForm(); form.uploadDir = 'tmp'; form.parse(request, function(error, fields, files) { console.log('parsing done'); fs.renameSync(files.upload.path, './tmp/test.png'); response.writeHead(200, { 'Content-Type': 'text/html' }); response.write('Received image:<br>'); response.write('<img src="/show">'); response.end(); }); } function show(response) { console.log('Request handler "show" was called.'); fs.readFile('./tmp/test.png', 'binary', function(error, file) { if (error) { response.writeHead(500, { 'Content-Type': 'text/plain' }); response.write(error + ' '); response.end(); } else { response.writeHead(200, { 'Content-Type': 'image/png' }); response.write(file, 'binary'); response.end(); } }); } exports.start = start; exports.upload = upload; exports.show = show;
主文件（index.js）
var server = require('./server'); var route = require('./route'); var requestHandlers = require('./requestHandlers'); var handler = {}; handler['/'] = requestHandlers.start; handler['/start'] = requestHandlers.start; handler['/upload'] = requestHandlers.upload; handler['/show'] = requestHandlers.show; server.start(route.route, handler);
打开终端，启动服务器 node index，浏览器输入 http://localhost:8888/start，上传图片功能就可以使用了。选择一张本地图片，将其上传到服务器，然后浏览器就会显示该图片。