计算机网络课设:网络聊天程序的设计与实现(java实现)

参照附录 1，了解 Socket 通信的原理，在此基础上编写一个聊天程序。

原理：用NIO（非阻塞式IO）写的服务端客户端，外加jwt写的界面。

一共三个java文件.（先运行服务端代码、再运行客户端代码）

GroupChatServer.java （服务端）


// 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<SelectionKey> 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();

    }
}

GroupChatClient .java（客户端）

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<SelectionKey> 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);
        }
    }
}

UI界面：

ClientFrame.java


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<rowcount;i++){
            if(model.getValueAt(i,1).equals(deladdress[1])){
                model.removeRow(i);
                break;
            }
        }
        model.fireTableDataChanged();
    }

    //创建当前在线列表
    JTable jtbOnline = new JTable
            (
                    new DefaultTableModel(rowDatatrue, colTitles) {
                        //表格不可编辑，只可显示
                        @Override
                        public boolean isCellEditable(int row, int column) {
                            return false;
                        }
                    }
            );

    //创建聊天消息框的滚动窗
    JScrollPane jspChat = new JScrollPane(jtaChat);

    //创建当前在线列表的滚动窗
    JScrollPane jspOnline = new JScrollPane(jtbOnline);

    //设置默认窗口属性，连接窗口组件
    public ClientFrame() {
        //标题
        setTitle("聊天室");
        //大小
        setSize(WIDTH, HEIGHT);
        //不可缩放
        setResizable(false);
        //设置布局:不适用默认布局，完全自定义
        setLayout(null);

        //设置按钮大小和位置
        btnClear.setBounds(140, 420, 100, 60);



        //设置按钮文本的字体
        btnClear.setFont(new Font("宋体", Font.BOLD, 18));

        //添加按钮

        this.add(btnClear);


        //聊天消息框自动换行
        jtaChat.setLineWrap(true);
        //聊天框不可编辑，只用来显示
        jtaChat.setEditable(false);
        //设置聊天框字体
        jtaChat.setFont(new Font("楷体", Font.BOLD, 16));

        //设置滚动窗的水平滚动条属性:不出现
        jspChat.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
        //设置滚动窗的垂直滚动条属性:需要时自动出现
        jspChat.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
        //设置滚动窗大小和位置
        jspChat.setBounds(20, 20, 360, 400);
        //添加聊天窗口的滚动窗
        this.add(jspChat);

        //设置滚动窗的水平滚动条属性:不出现
        jspOnline.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
        //设置滚动窗的垂直滚动条属性:需要时自动出现
        jspOnline.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
        //设置当前在线列表滚动窗大小和位置
        jspOnline.setBounds(420, 20, 250, 400);
        //添加当前在线列表
        this.add(jspOnline);

        //添加清屏按钮的响应事件
        btnClear.addActionListener
                (
                        new ActionListener() {
                            @Override
                            public void actionPerformed(ActionEvent event) {
                                //聊天框清屏
                                jtaChat.setText("");
                            }
                        }
                );

        this.show();
    }
}

实现的功能（下图为服务端代码运行后生成界面）：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。

服务端命令行：

客户端1：客户端2 ：

计算机网络课设:网络聊天程序的设计与实现(java实现)

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