HTTP1.0工作原理

1.HTTP工作原理

《HTTP响应报文与工作原理详解》讲的比较详细了。

2.示例

（1）server端程序如下：

package org.yeyouluo.demo.jsp;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
* 实现HTTP 1.0的服务器，对于所有的HTTP请求，会把HTTP请求头响应回去。
* @author yeyouluo
*
*/
public class MyHTTPServer {

public static void main(String[] args) throws IOException {
int port = 80;
ServerSocket serverSocket = new ServerSocket(port);
System.out.println("启动服务，绑定端口： " + port);

ExecutorService fixedThreadPool = Executors.newFixedThreadPool(30);  //5.线程池

//6.这个循环不停监听socket连接，使用SocketHandler处理连入的socket，而这个处理是放在线程池中的。
while(true){
Socket clientSocket = serverSocket.accept();
System.out.println("新的连接"+clientSocket.getInetAddress() + ":" + clientSocket.getPort());
try{
fixedThreadPool.execute(new SocketHandler(clientSocket));
}catch(Exception e){
e.printStackTrace();
}
}
}

}

class SocketHandler implements Runnable{
static final String CRLF = "\r\n";  //1.换行符
private Socket clientSocket;

public SocketHandler(Socket clientSocket) {
super();
this.clientSocket = clientSocket;
}

public void handleSocket(Socket clientSocket) throws IOException{
BufferedReader in = new BufferedReader(
new InputStreamReader(clientSocket.getInputStream())
);

PrintWriter out = new PrintWriter(
new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()))
,true);

String requestHeader = "";
String s;
while( (s = in.readLine()) != null ){
s +=  CRLF;  //2.很重要，默认情况下in.readLine的结果中'\r\n'被去掉了
requestHeader += s;
if( CRLF.equals(s) ){  //如果读取的一行数据只有换行符，说明请求头已经结束了
break;
}
}

System.out.println("客户端请求头：\n" + requestHeader);

String responseBody = "客户端的请求头是：\n"+requestHeader;
String responseHeader = "HTTP/1.0 200 OK\r\n" +
"Content-Type: text/plain; charset=UTF-8\r\n" +
"Content-Length: "+responseBody.getBytes().length+"\r\n" +
"\r\n";
System.out.println("响应头：\n" + responseHeader);

out.write(responseHeader);
out.write(responseBody);
out.flush();

out.close();
in.close();
clientSocket.close();
}

@Override
public void run() {
try {
handleSocket(clientSocket);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}

server端
启动server端。

（2）client端直接通过浏览器或curl工具发送http请求即可。比如在浏览器中输入http://127.0.0.1 。

（3）server端控制台打印如下：

3.参考

http://wiki.jikexueyuan.com/project/java-web/00-02.html