[nodejs] day1-创建服务器

一、使用匿名函数(新建文件service.js)创建一个服务器：

 var http = require("http"); //Node.js自带的 http 模块，并且把它赋值给 http 变量
  //使用匿名函数的方法
 http.createServer(function(request, response){ //调用http模块提供的函数： createServer
     console.log("Request received");
     response.writeHead(200,{"Content-Type":"text/plain"});
     response.write("hello world");
     response.end();
 }).listen(8088); //指定这个HTTP服务器监听的端口号

运行node service.js，在浏览器输入127.0.0.1:8088，就可以看到熟悉的hello world了~

二、使用非匿名函数(新建文件service.js)创建服务器：

 var http = require("http"); //Node.js自带的 http 模块，并且把它赋值给 http 变量
 
 //使用传递函数的方法
 var myfunction = function(request, response){
     response.writeHead(200,{"Content-Type":"text/plain"});
     response.write("hello");
     response.end();
 }
 var myservice = http.createServer(myfunction);
 myservice.listen(8088);

运行node service.js，在浏览器输入127.0.0.1:8088，就可以看到熟悉的hello world了~

三、使用模块分离的方式来创建一个服务器，新建service.js，输入：

 var http = require("http"); //Node.js自带的 http 模块，并且把它赋值给 http 变量
 function start(){
     function onRequest(request,response){
         console.log('Request received.')
         response.writeHead(200,{"Content-Type":"text/plain"});
         response.write("hello world");
         response.end();
     }
 
     http.createServer(onRequest).listen(8088);
     console.log("Server has started.");
 }
 
 exports.start = start;//模块函数导出

创建index.js ，输入：

 var service = require("./service");
 service.start();

运行node index.js，在浏览器输入127.0.0.1:8088，就可以看到熟悉的hello world了~

四、为服务器增加一个路由模块，并注入到service.js中：

service.js:

 var http = require("http"); //Node.js自带的 http 模块，并且把它赋值给 http 变量
 var url = require("url");//对路由进行解析的模块
 function start(route){ //传递了一个参数给start,在index.js中，回把路由注入进去
     function onRequest(request,response){
         /*
         * 对于一个URL: http://localhost:8088/start?foo=bar&hello=world
         * 以下的pathname得到的是"start"
         * */
         var pathname = url.parse(request.url).pathname;
         console.log("Request for "+pathname+"received");
 
         route(pathname);//将参数传递给路由
 
         console.log('Request received.')
         response.writeHead(200,{"Content-Type":"text/plain"});
         response.write("hello world");
         response.end();
     }
 
     http.createServer(onRequest).listen(8088);
     console.log("Server has started.");
 }
 
 exports.start = start;

route.js:

 function route(pathname){
     console.log("About to route a request for "+pathname);
 }
 
 exports.route = route;

最后，index.js:

 var service = require("./service");//使service模块可以被注入到服务器中
 var route = require("./route");//使route模块可以被注入到服务器中
 service.start(route.route);

运行node index.js，启动服务，在浏览器中输入 http://localhost:8088/start?foo=bar&hello=world，

在交互窗口可以看到输入的对路由的解析哦~

五、为服务器将路由模块和路由的处理函数分离开来，用数组关联在一起（松耦合）

路由对应的处理方法：requestHandles.js

 //为不同请求提供出来方法
 function start(){
     console.log("Request handler 'start' was called.");
 }
 
 function upload(){
     console.log("Request handler 'upload' was called.");
 }
 
 exports.start = start;
 exports.upload = upload;

将路由处理方法和路由的路径耦合在一起，index.js:

 var service = require("./service");//使service模块可以被注入到服务器中
 var route = require("./route");//使route模块可以被注入到服务器中
 var requestHandlers = require("./requestHandlers");
 
 var handle = {}
 handle["/"] = requestHandlers.start;
 handle["/start"] = requestHandlers.start;
 handle["/upload"] = requestHandlers.upload;
 
 service.start(route.route, handle);

路由处理，route.js:

 function route(handle,pathname){
     console.log("About to route a request for "+pathname);
     if(typeof handle[pathname] === 'function'){
         handle[pathname]();
     }else{
         console.log("No request handler found for "+pathname);
     }
 }
 
 exports.route = route;

service.js:

 var http = require("http"); //Node.js自带的模块，并且把它赋值给变量
 var url = require("url");
 
 function start(route, handle){ //依赖注入，将路由和处理都注入
     function onRequest(request,response){
         /*
         * 对于一个URL: http://localhost:8088/start?foo=bar&hello=world
         * 以下的pathname得到的是"start"
         * */
         var pathname = url.parse(request.url).pathname;
         console.log("Request for "+pathname+"received");
 
         route(handle,pathname);//将参数传递给路由
 
         console.log('Request received.')
         response.writeHead(200,{"Content-Type":"text/plain"});
         response.write("hello world");
         response.end();
     }
 
     http.createServer(onRequest).listen(8088);
     console.log("Server has started.");
 }
 
 exports.start = start;

入口模块：index.js

 var service = require("./service");//使service模块可以被注入到服务器中
 var route = require("./route");//使route模块可以被注入到服务器中
 var requestHandlers = require("./requestHandlers");
 
 var handle = {}
 handle["/"] = requestHandlers.start;
 handle["/start"] = requestHandlers.start;
 handle["/upload"] = requestHandlers.upload;
 
 service.start(route.route, handle);