最近复习计算机网络,复习完应用层之后对于理论知识还是没有一个深刻的概念,索性就动手用Java Socket API 模拟做一个HTTP服务器,巩固一下应用层的知识。
HTTP基于TCP协议,协议采用了请求/响应模型。客户端向服务器发送一个请求,请求头包含请求的方法、URL、协议版本、以及包含请求修饰符、客户信息和内容的类似于MIME的消息结构。服务器以一个状态行作为响应,响应的内容包括消息协议的版本,成功或者错误编码加上包含服务器信息、实体元信息以及可能的实体内容——百度百科。
话不多说,还是直接上图。
具体字段这里不作解释,不懂的请先自己了解http协议。这里主要是根据请求响应这一过程模拟HTTP服务器。
下面是代码:
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package com.example.httpserver; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.ServerSocket; import java.net.Socket; public class HttpServer { private static final Integer port = 80 ; //HTTP默认端口80 public static void main(String[] args) { ServerSocket serverSocket; try { //建立服务器Socket,监听客户端请求 serverSocket = new ServerSocket(port); System.out.println( "Server is running on port:" +serverSocket.getLocalPort()); //死循环不间断监听客户端请求 while ( true ){ final Socket socket = serverSocket.accept(); System.out.println( "biuld a new tcp link with client,the cient address:" + socket.getInetAddress()+ ":" +socket.getPort()); //并发处理HTTP客户端请求 service(socket); } } catch (IOException e) { e.printStackTrace(); } } public static void service(Socket socket) { new Thread(){ public void run(){ InputStream inSocket; try { //获取HTTP请求头 inSocket = socket.getInputStream(); int size = inSocket.available(); byte [] buffer = new byte [size]; inSocket.read(buffer); String request = new String(buffer); System.out.println( "ClientBrowser:\n" +request+ "\n" + "------------------------------------------------------------------" ); String firstLineOfRequest = "" ; String[] heads; String uri = "/index.html" ; String contentType = "" ; if (request.length() > 0 ){ firstLineOfRequest = request.substring( 0 ,request.indexOf( "\r\n" )); heads = firstLineOfRequest.split( " " ); uri = heads[ 1 ]; if (uri.indexOf( "html" ) != - 1 ){ contentType = "text/html" ; } else { contentType = "application/octet-stream" ; } } //将响应头发送给客户端 String responseFirstLine = "HTTP/1.1 200 OK\r\n" ; String responseHead = "Content-Type:" + contentType + "\r\n" ; OutputStream outSocket = socket.getOutputStream(); System.out.println( "ServerResponse:\n" +responseFirstLine+ "\n" +responseHead+ "\n" + "--------------------------------------------------------------------" ); outSocket.write(responseFirstLine.getBytes()); outSocket.write(responseHead.getBytes()); //通过HTTP请求中的uri读取相应文件发送给客户端 FileInputStream writehtml = new FileInputStream( new File( "wwwroot" +uri)); outSocket.write( "\r\n" .getBytes()); byte [] htmlbuffer = new byte [writehtml.available()]; if (writehtml != null ){ int len = 0 ; System.out.println( "writeHtml" ); while ((len = writehtml.read(htmlbuffer)) != - 1 ){ outSocket.write(htmlbuffer, 0 ,len); } } outSocket.close(); socket.close(); } catch (IOException e) { e.printStackTrace(); } } }.start(); } } |
代码看注释也很容易理解。现在我们在浏览器中输入服务器地址+要访问的文件
在看我们控制台输出的内容:
以上就是Java Socket 简单的模拟HTTP服务器全过程。希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:http://www.jianshu.com/p/2ff10a02b2b8#