web 服务器 路由

var http = require("http");
var fs = require("fs");

var server = http.createServer(function (request, response) {

    var url = request.url;
    if (url === "/" || url === "/index") {
        response.writeHead(200, { "Content-type": "text/html" })
        var stream = fs.createReadStream(__dirname + "/index.html", "utf-8");
        stream.pipe(response);
    }
    else if (url === "/home") {
        response.writeHead(200, { "Content-type": "text/html" })
        var stream = fs.createReadStream(__dirname + "/home.html", "utf-8");
        stream.pipe(response);
    }
    else {
        response.writeHead(200, { "Content-type": "text/html" })
        var stream = fs.createReadStream(__dirname + "/error.html", "utf-8");
        stream.pipe(response);
    }
});

server.listen(4000, "127.0.0.1");

server.on("error", function (e) {

    if (e.code == "EADDRINUSE") {
        console.log("in error")
        setTimeout(function () {
            server.close();
            server.listen(4000, "127.0.0.1")
        }, 1000);
    }
})

console.log("server has started")