IO(1)

package io;

import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * Created by dingshuangkun on 2017/12/30.
 */
public class Server {

    private static int count = 1;

    public static void main(String[] arges) throws Exception {
        ServerSocket ss = new ServerSocket(8080);
        System.out.println("服務器啓動");
        while (true) {
            // 阻塞
            final Socket socket = ss.accept();
            System.out.println("新建客戶端" + count);
            count++;
            handler(socket);
        }
    }

    public static void handler(Socket socket) {
        try {
            byte[] b = new byte[1024];
            InputStream inputStream = socket.getInputStream();
            while (true) {
                // 阻塞
                int read = inputStream.read(b);
                if (read != -1) {
                    System.out.println(new String(b,0,read));
                }else {
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            System.out.println("socket 關閉");
            try {
                socket.close();
            }catch (IOException e){
                e.printStackTrace();
            }
        }
    }
}

下面在瀏覽器中訪問

 

在瀏覽器中開啓了3個窗口 訪問服務

結果是隻有一個窗口訪問到而且輸出結果。其它窗口被阻塞

第一個窗口被阻塞在這裏，致使其它線程被阻塞在這裏

缺點很明顯，單線程狀況下只能有一個客戶端。一個線程管理一個鏈接