网络聊天程序的设计与实现——计网课设

实验题目

网络聊天程序的设计与实现

• 实验目的

  使用socket编程，了解socket编程的通信原理，会使用socket进行简单的网络编程，在此基础上编写一聊天程序，能够运行程序，运行客户端和服务器端，实现两个客户端通过服务器端进行通信。

  • 总体设计

    1、背景知识

    1.1 Tcp协议与Win Sock网络编程接口：

    Tcp协议： 是面向连接的运输层协议，提供可靠的、有序的、双向的、面向连接的运输服务。

    Win Sock编程： 是一种网络编程接口，实际上是作为TCP/IP协议的一种封装。可以通过调用WinSock的接口函数来调用TCP/IP的各种功能。

    WinSock 编程简单流程：WinSock编程分为服务器端和客户端两部分。

    2、实现的功能

    1、显示上线下线时间  

    2、服务端监听上线的客户端的IP和端口号

    3、一个客户端发消息后(注：客户端在java编译器的终端输入消息)服务器能接收并转发消息给其他客户端     

    4、清屏

    如何在局域网中使用：  修改客户端代码中的  private final String HOST = "127.0.0.1" 改为接入的局域网服务器的IP即可

    3、代码

    package GroupChat;
    import javax.swing.*;
    import javax.swing.table.DefaultTableModel;
    import javax.swing.table.TableModel;
    import java.awt.*;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.awt.event.MouseEvent;
    import java.awt.event.MouseListener;
    import java.io.OutputStream;
    import java.text.SimpleDateFormat;
    import java.util.ArrayList;
    import java.util.Date;
    class ClientFrame extends JFrame {
        //时间显示格式
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        //窗口宽度
        final int WIDTH = 700;
        //窗口高度
        final int HEIGHT = 600;
        //创建发送按钮
        JButton btnSend = new JButton("发送");
        //创建清除按钮
        JButton btnClear = new JButton("清屏");
        //创建退出按钮
        JButton btnExit = new JButton("退出");
        //创建聊天消息框
        JTextArea jtaChat = new JTextArea();
        //当前在线列表的列标题
        String[] colTitles = {"IP", "端口"};
        //当前在线列表的数据,暂存在动态数组中
        String[][] rowDatatrue;
        public void setRowData(String address,String port){
            String[] newaddress = {address,port};
            jtaChat.append(sdf.format(new Date()) + "\n: " + address+":"+port  + "上线了\n");
            DefaultTableModel  model = (DefaultTableModel)jtbOnline.getModel();
            model.addRow(new Object[]{newaddress[0],newaddress[1]});
            jtbOnline.setModel(model);
        }
        public void addinfo(String msg){
            jtaChat.append(sdf.format(new Date()) + "\n: " + msg.trim() +"\n");
        }
        public void delRowData(String address,String port){
            String[] deladdress = {address,port};
            jtaChat.append(sdf.format(new Date()) + "\n: " + address+":"+port  + "离线了\n");
            DefaultTableModel  model = (DefaultTableModel)jtbOnline.getModel();
            int rowcount= model.getRowCount();
            for(int i=0;i 
    客户端（想要几个客户就创建几个客户端） 
     
    package GroupChat;
    import java.io.IOException;
    import java.net.InetSocketAddress;
    import java.nio.ByteBuffer;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.SocketChannel;
    import java.util.Iterator;
    import java.util.Scanner;
    public class GroupChatClient {
        private final String HOST = "127.0.0.1";//服务器的ip
        private final int PORT = 6667;//服务器端口
        private Selector selector;
        private SocketChannel socketChannel;
        private String username;
        //构造器,完成初始化工作
        public GroupChatClient() throws IOException {
            selector = Selector.open();
            //连接服务器
            socketChannel = SocketChannel.open(new InetSocketAddress(HOST, PORT));
            //设置非阻塞
            socketChannel.configureBlocking(false);
            //将 channel 注册到selector
            socketChannel.register(selector, SelectionKey.OP_READ);
            //得到 username
            username = socketChannel.getLocalAddress().toString().substring(1);
            System.out.println(username + " is ok...");
        }
        //向服务器发送消息
        public void sendInfo(String info) {
            info = username + " 说：" + info;
            try {
                socketChannel.write(ByteBuffer.wrap(info.getBytes()));
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        //读取从服务器端回复的消息
        public void readInfo() {
            try {
                int readChannels = selector.select();
                if (readChannels > 0) {//有可以用的通道
                    Iterator iterator = selector.selectedKeys().iterator();
                    while (iterator.hasNext()) {
                        SelectionKey key = iterator.next();
                        if (key.isReadable()) {
                            //得到相关的通道
                            SocketChannel sc = (SocketChannel) key.channel();
                            //得到一个 Buffer
                            ByteBuffer buffer = ByteBuffer.allocate(1024);
                            //读取
                            sc.read(buffer);
                            //把读到的缓冲区的数据转成字符串
                            String msg = new String(buffer.array());
                            System.out.println(msg.trim());
                        }
                    }
                    iterator.remove(); //删除当前的 selectionKey,防止重复操作
                } else {
                    //System.out.println("没有可以用的通道...");
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        public static void main(String[] args) throws Exception {
            //启动我们客户端
            GroupChatClient chatClient = new GroupChatClient();
            //启动一个线程,每个 3 秒，读取从服务器发送数据
            new Thread() {
                public void run() {
                    while (true) {
                        chatClient.readInfo();
                        try {
                            Thread.currentThread().sleep(3000);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }.start();
            //发送数据给服务器端
            Scanner scanner = new Scanner(System.in);
            while (scanner.hasNextLine()) {
                String s = scanner.nextLine();
                chatClient.sendInfo(s);
            }
        }
    }
     
     服务器端
     
    package GroupChat;
    // 服务端：
    import java.io.IOException;
    import java.net.InetSocketAddress;
    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.util.Iterator;
    public class GroupChatServer {
        //定义属性
        private Selector selector;
        private ServerSocketChannel listenChannel;
        private ClientFrame clientFrame;
        private static final int PORT = 6667;
        //构造器
        //初始化工作
        public GroupChatServer() {
            clientFrame = new ClientFrame();
            try {
                //得到选择器
                selector = Selector.open();
                //ServerSocketChannel
                listenChannel = ServerSocketChannel.open();
                //绑定端口
                listenChannel.socket().bind(new InetSocketAddress(PORT));
                //设置非阻塞模式
                listenChannel.configureBlocking(false);
                //将该 listenChannel 注册到 selector
                listenChannel.register(selector, SelectionKey.OP_ACCEPT);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        public void listen() {
            try {
                //循环处理
                while (true) {
                    int count = selector.select();
                    if (count > 0) { //有事件处理
                        // 遍历得到 selectionKey 集合
                        Iterator iterator = selector.selectedKeys().iterator();
                        while (iterator.hasNext()) {
                            //取出 selectionkey
                            SelectionKey key = iterator.next();
                            //监听到 accept
                            if (key.isAcceptable()) {
                                SocketChannel sc = listenChannel.accept();
                                sc.configureBlocking(false);
                                //将该 sc 注册到 seletor
                                sc.register(selector, SelectionKey.OP_READ);
                                //提示
    //                            System.out.println(sc.getRemoteAddress() + " 上线 ");
                                String remoteaddress = sc.getRemoteAddress().toString();
                                String[] split = remoteaddress.split(":");
                                clientFrame.setRowData(split[0],split[1]);
                            }
                            if (key.isReadable()) {//通道发送read事件，即通道是可读的状态
                                // 处理读(专门写方法..)
                                readData(key);
                            }
                            //当前的 key 删除，防止重复处理
                            iterator.remove();
                        }
                    } else {
                        System.out.println("等待....");
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                //发生异常处理....
            }
        }
        //读取客户端消息
        public void readData(SelectionKey key) {
            SocketChannel channel = null;
            try {
                //得到 channel
                channel = (SocketChannel) key.channel();
                //创建 buffer
                ByteBuffer buffer = ByteBuffer.allocate(1024);
                int count = channel.read(buffer);
                //根据 count 的值做处理
                if (count > 0) {
                    //把缓存区的数据转成字符串
                    String msg = new String(buffer.array());
                    //输出该消息
                    System.out.println("form客户端:" + msg);
                    clientFrame.addinfo(msg);
                    //向其它的客户端转发消息(去掉自己),专门写一个方法来处理
                    sendInfoToOtherClients(msg, channel);
                }
            } catch (IOException e) {
                try {
                    System.out.println(channel.getRemoteAddress() + "离线了..");
                    String remoteaddress = channel.getRemoteAddress().toString();
                    String[] split = remoteaddress.split(":");
                    clientFrame.delRowData(split[0],split[1]);
                    //取消注册
                    key.cancel();
                    //关闭通道
                    channel.close();
                } catch (IOException e2) {
                    e2.printStackTrace();
                }
            }
        }
        //转发消息给其它客户(通道)
        private void sendInfoToOtherClients(String msg, SocketChannel self) throws IOException {
            System.out.println("服务器转发消息中...");
            //遍历所有注册到 selector 上的 SocketChannel,并排除 self
            for (SelectionKey key : selector.keys()) {
                //通过 key 取出对应的 SocketChannel
                Channel targetChannel = key.channel();
                //排除自己
                if (targetChannel instanceof SocketChannel && targetChannel != self) {
                    //转型
                    SocketChannel dest = (SocketChannel) targetChannel;
                    //将 msg 存储到 buffer
                    ByteBuffer buffer = ByteBuffer.wrap(msg.getBytes());
                    //将 buffer 的数据写入通道
                    dest.write(buffer);
                }
            }
        }
        public static void main(String[] args) {
            //创建服务器对象
            GroupChatServer groupChatServer = new GroupChatServer();
            groupChatServer.listen();
        }
    }
     
    运行结果 
     
    客户端命令行：  
     
                             
     
     客户端1：
     
      
     
    客户端2：                                 
     
     
    客户端3：