package newtest;

 import java.io.BufferedReader;

 import java.io.IOException;

 import java.io.InputStreamReader;

 import java.net.InetSocketAddress;

 import java.net.Socket;

 import java.nio.ByteBuffer;

 import java.nio.channels.Channel;

 import java.nio.channels.SelectionKey;

 import java.nio.channels.Selector;

 import java.nio.channels.ServerSocketChannel;

 import java.nio.channels.SocketChannel;

 import java.nio.charset.Charset;

 public class TcpServer

 {

     //用于检测所有Channel状态的selector

     private Selector selector = null;

     //定义编码格式

     private Charset charset = Charset.forName("UTF-8");

     public void init()throws IOException

     {

         selector = Selector.open();

         //通过open方法来打开一个未绑定的ServerSocketChannel实例

         ServerSocketChannel server  = ServerSocketChannel.open();

         InetSocketAddress isa = new InetSocketAddress("127.0.0.1", 8899);

         //将该ServerSocketChannel绑定到指定IP地址

         server.socket().bind(isa);

         //设置ServerSocket以非阻塞方式工作

         server.configureBlocking(false);

         //将Server注册到指定Selector对象

         server.register(selector, SelectionKey.OP_ACCEPT);

         while(selector.select() > 0)

         {

             //依次处理Selector上的每个已选择的SelectionKey

             for(SelectionKey sk : selector.selectedKeys())

             {

                 //从selector上的已选择Key集中删除正在处理的SelectionKey

                 selector.selectedKeys().remove(sk);

                 //如果sk对应的通道包含客户端的连接请求

                 if(sk.isAcceptable())

                 {

                     //调用accept方法接受连接，产生服务器端对应的SocketChannel

                     SocketChannel sc = server.accept();

                     //设置非阻塞方式工作

                     sc.configureBlocking(false);

                     //将该SocketChnnel也注册到selector

                     sc.register(selector, SelectionKey.OP_READ);

                     //将sk对应的Channel设置成准备接受其它请求

                     sk.interestOps(SelectionKey.OP_ACCEPT);

                 }

                 //如果sk对应的通道有数据需要读取

                 if(sk.isReadable())

                 {

                     //获取该SelectionKey对应的Channel,该Channnel中有可读的数据

                     SocketChannel sc = (SocketChannel)sk.channel();

                     //定义准备执行读取数据的ByteBuffer

                     ByteBuffer buff = ByteBuffer.allocate(1024);

                     String content =  "";

                     //开始读数据

                     try

                     {

                         while(sc.read(buff) > 0)

                         {

                             buff.flip();

                             content += charset.decode(buff);

                         }

                         //打印从该sk对应的Channel里读到的数据

                         System.out.println("消息：" + content);

                         //将sk对应的Channel设置成准备下一次读取

                         sk.interestOps(SelectionKey.OP_READ);

                     }

                     //如果捕捉到该sk对应的Channel出现了异常，即表明该Channel对应的Client出现了问题

                     //所以从Selector中取消sk的注册

                     catch(IOException ex)

                     {

                         //从Selector中删除指定的SelectionKey

                         sk.cancel();

                         if(sk.channel() != null)

                         {

                             sk.channel().close();

                         }

                     }

 //                    throw new IOException();

                     //如果content的长度大于0，即聊天信息不为空

                     if(content.length() > 0)

                     {

                         //遍历该selector里注册的所有selectionKey

                         for(SelectionKey key : selector.keys())

                         {

                             //获取该channel是SocketChannel对象

                             Channel targetChannel = key.channel();

                             if(targetChannel instanceof SocketChannel)

                             {

                                 //将读到的内容写入该Channel中

                                 SocketChannel dest = (SocketChannel)targetChannel;

                                 dest.write(charset.encode(content));

                             }

                         }

                     }

                 }

             }

         }

     }

     public static void main(String[] args)throws IOException

     {

         System.out.println("===========TCP的server端启动=============");

         new TcpServer().init();

     }

 }

package com.springboot.springbootswagger.client;

import java.io.DataInputStream;

import java.io.DataOutputStream;

import java.io.IOException;

import java.net.Socket;

import java.net.UnknownHostException;

public class TcpClient {

    // initialize socket and input output streams

    private Socket socket            = null;

    private DataInputStream  input   = null;

    private DataOutputStream out     = null;

    // constructor to put ip address and port

    public TcpClient(String address, int port)

    {

        // establish a connection

        try

        {

            socket = new Socket(address, port);

            System.out.println("Connected");

            // takes input from terminal

            input  = new DataInputStream(System.in);

            out    = new DataOutputStream(socket.getOutputStream());

        }

        catch(UnknownHostException u)

        {

            System.out.println(u.toString());

        }

        catch(IOException i)

        {

            System.out.println(i);

        }

        // 待读入的String

        String line = "";

        // 一直读到Over字符停止

        while (!line.equals("Over"))

        {

            try

            {

                line = input.readLine();

                out.writeUTF(line);

            }

            catch(IOException i)

            {

                System.out.println(i);

            }

        }

        // 关闭连接

        try

        {

            input.close();

            out.close();

            socket.close();

        }

        catch(IOException i)

        {

            System.out.println(i);

        }

    }

    public static void main(String args[])

    {

        TcpClient client = new TcpClient("127.0.0.1", 8899);

    }

}