用java写一个最简单的http Server

How to create HTTP Server in Java

import java.io.IOException;
import java.net.ServerSocket; 
import java.net.Socket; 
import java.util.Date; 
/** * Java program to create a simple HTTP Server to demonstrate how to use * ServerSocket and Socket class. * * 
@author Javin Paul*/ 
public class SimpleHTTPServer 
{ 
    public static void main(String args[]) throws IOException 
    { 
        ServerSocket server = new ServerSocket(8080);
        System.out.println("Listening for connection on port 8080 ...."); 
        while (true) 
        { 
          try (Socket socket = server.accept()) 
          { 
              //读取request
              InputStreamReader isr = new InputStreamReader(socket.getInputStream()); 
              BufferedReader reader = new BufferedReader(isr); 
              String line = reader.readLine(); 
              while (!line.isEmpty()) 
              { 
                  System.out.println(line); 
                  line = reader.readLine();
              } 
              //写入response
              Date today = new Date(); 
              String httpResponse = "HTTP/1.1 200 OK\r\n\r\n" + today; 
              socket.getOutputStream().write(httpResponse.getBytes("UTF-8")); 
          } 
        } 
    } 
} 

建立web server，监听8080端口上的connection

ServerSocket server = new ServerSocket(8080);

读取connection。这是一个阻塞函数。当有从client过来的connect时，这个函数会返回一个socket，用来读取request和写入response。server会一直循环监听connect，直至server自己stop。

Socket socket = server.accept()

读取request

InputStreamReader isr = new InputStreamReader(socket.getInputStream()); 

写入response

socket.getOutputStream().write(httpResponse.getBytes("UTF-8"));

这种写法，没有处理多个connect。当一个connect正在处理的时候，其他的connect必须等待。使用thread或Java NIO non blocking selectors and channels来处理并发。