java Socket实现简单模拟HTTP服务器

2019-11-26 12:19:50

字体：大中小

来源：转载

供稿：网友

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：

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