最原始的版本

客户端服务端BIOServer

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

//最原始的版本
public class BIOServer {

    public static void main(String[] args) throws Exception {
        ServerSocket serverSocket = new ServerSocket(8080); //Socket 插座的意思
        System.out.println("服务器启动成功");
        while (!serverSocket.isClosed()) {  //isClosed 是否是关闭的
            Socket request = serverSocket.accept();// 阻塞 accept(吸收)方法: 如何没有新的连接过来 就会一直等待
            System.out.println("收到新连接 : " + request.toString());
            try {
                // 接收数据、打印  读取数据
                InputStream inputStream = request.getInputStream(); // net + i/o
                BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "utf-8"));
                String msg;
                while ((msg = reader.readLine()) != null) { // 没有数据，阻塞
                    if (msg.length() == 0) {
                        break;
                    }
                    System.out.println(msg);
                }
                System.out.println("收到数据,来自："+ request.toString());
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    request.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        serverSocket.close();
    }
}

结果:

服务器取得成功

阻塞提示:

客户端

import java.io.OutputStream;
import java.net.Socket;
import java.nio.charset.Charset;
import java.util.Scanner;

public class BIOClient {
	private static Charset charset = Charset.forName("UTF-8");

	public static void main(String[] args) throws Exception {
		Socket s = new Socket("localhost", 8080); //直接new (插孔)对象(服务端的host ,post)
        //往外发数据
		OutputStream out = s.getOutputStream();
        //控制台写入发给服务器
		Scanner scanner = new Scanner(System.in);
		System.out.println("请输入：");
		String msg = scanner.nextLine();
		out.write(msg.getBytes(charset)); // 阻塞，写完成才会 返回
		scanner.close();
		s.close();
	}

}

请输入:
123
Process finished with exit code 0[这行是蓝色的 ,我输入了123]

在回头看服务器