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 + '\n');
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。