若url为：

    http://localhost:8888/select?name=a&id=5

http.createServer(function(request,response){
        var pathname = url.parse(request.url).pathname;  //pathname => select
        var arg = url.parse(request.url).query;          //arg => name=a&id=5
        console.log("Request for " + arg );

        var name = querystring.parse(arg).name;         //name => a
        console.log("name = "+name);

        console.log("Request for " + pathname + " received.");
    }).listen(8888); 

//querystring.parse(arg)   => { name: 'a', id: '5' }

更多信息:   http://nodejs.org/api/url.html