java TCP端口监听

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * 
 * 服务器端程序：
 * 
 * 1. 监听一端口，等待客户接入； 2. 一旦有客户接入，就构造一个Socket会话对象； 3. 将这个会话交给线程处理，然后主程序继续监听。
 * 
 * @author OKJohn
 * @version 1.0
 */

public class Server extends ServerSocket {

	public Server(int serverPort) throws IOException {
		// 用指定的端口构造一个ServerSocket
		super(serverPort);
		try {
			while (true) {
				// 监听一端口，等待客户接入
				Socket socket = accept();
				// 将会话交给线程处理
				new ServerThread(socket);
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			close(); // 关闭监听端口
		}
	}

	// inner-class ServerThread
	class ServerThread extends Thread {
		private Socket socket;
		private BufferedReader in;
		private PrintWriter out;

		// Ready to conversation
		public ServerThread(Socket s) throws IOException {
			this.socket = s;
			// 构造该会话中的输入输出流
			in = new BufferedReader(new InputStreamReader(socket
					.getInputStream(), "GB2312"));
			out = new PrintWriter(socket.getOutputStream(), true);
			start();
		}

		// Execute conversation
		public void run() {
			try {

				// Communicate with client until "bye " received.
				while (true) {
					// 通过输入流接收客户端信息
					String line = in.readLine();
					if (line == null || "".equals(line.trim())) { // 是否终止会话
						break;
					}
					System.out.println("Received   message: " + line);
					// 通过输出流向客户端发送信息
					out.println(line);
					out.flush();
				}

				out.close();
				in.close();
				socket.close();

			} catch (IOException e) {
				e.printStackTrace();
			}
		}

	}

	// main method
	public static void main(String[] args) throws IOException {
		new Server(2088);
	}
}

 

在浏览器输入：http://localhost:2088/hello.do

浏览器显示：

GET /hello.do HTTP/1.1
Host: localhost:2088
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.2.12) Gecko/20101026 Firefox/3.6.12
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: zh-cn,zh;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: GB2312,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive

 

评论

1 楼 xsgkaka 2013-01-30  

public Server(int serverPort) throws IOException {  
        // 用指定的端口构造一个ServerSocket  
        super(serverPort);  
        try {  
            while (true) {  
                // 监听一端口，等待客户接入  
                Socket socket = accept();  
                // 将会话交给线程处理  
                new ServerThread(socket);  
            }  
        } catch (IOException e) {  
            e.printStackTrace();  
        } finally {  
            close(); // 关闭监听端口  
        }  
    }  

while 循环内部为什么一直都在生成新的socket呢，ServerSocket的accept方法不是监听端口是否有请求介入的吗？那在new ServerThread（socket）方法之前为什么不判断一下 是否有请求接入啊？等有请求接入了在去执行线程处理函数。而是不停地产生新的socket去监听。