第十二章网络编程 - 4.[练习]GUI UDP实现聊天室 - 《Java基础》

实现效果
代码实现
实现效果

代码实现

package cn.giteasy.socket;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.*;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Demo04MyGUIChat extends Frame {
    private TextField tf;
    private Button send;
    private Button log;
    private Button clear;
    private Button shake;
    private TextArea viewText;
    private TextArea sendText;
    private DatagramSocket socket;
    private BufferedWriter bw;
    public Demo04MyGUIChat() {
        init();
        southPanel();
        centerPanel();
        event();
    }
    public void event() {
        this.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                try {
                    socket.close();
                    bw.close();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
                System.exit(0);
            }
        });
        send.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    send();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        });
        log.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    logFile();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        });
        clear.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                viewText.setText("");
            }
        });
        shake.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    send(new byte[]{-1},tf.getText());
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        });
        sendText.addKeyListener(new KeyAdapter() {
            @Override
            public void keyReleased(KeyEvent e) {
                //if(e.getKeyCode() == KeyEvent.VK_ENTER && e.isControlDown()) {    //isControlDown ctrl是否被按下
                if(e.getKeyCode() == KeyEvent.VK_ENTER) {
                    try {
                        send();
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                }
            }
        });
    }
    private void shake() {
        int x = this.getLocation().x;                            //获取横坐标位置
        int y = this.getLocation().y;                            //获取纵坐标位置
        for(int i = 0; i < 3; i++) {
            try {
                this.setLocation(x + 5, y + 5);
                Thread.sleep(20);
                this.setLocation(x + 5, y - 5);
                Thread.sleep(20);
                this.setLocation(x - 5, y + 5);
                Thread.sleep(20);
                this.setLocation(x - 5, y - 5);
                Thread.sleep(20);
                this.setLocation(x, y);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    private void logFile() throws IOException {
        bw.flush();                                    //刷新缓冲区
        FileInputStream fis = new FileInputStream("db.txt");
        ByteArrayOutputStream baos = new ByteArrayOutputStream();    //在内存中创建缓冲区
        int len;
        byte[] arr = new byte[8192];
        while((len = fis.read(arr)) != -1) {
            baos.write(arr, 0, len);
        }
        String str = baos.toString();                //将内存中的内容转换成了字符串
        viewText.setText(str);
        fis.close();
    }
    private void send(byte[] arr, String ip) throws IOException {
        DatagramPacket packet = 
                new DatagramPacket(arr, arr.length, InetAddress.getByName(ip), 9999);
        socket.send(packet);                        //发送数据
    }
    private void send() throws IOException {
        String message = sendText.getText();        //获取发送区域的内容
        String ip = tf.getText();                    //获取ip地址;
        ip = ip.trim().length() == 0 ? "255.255.255.255" : ip;
        send(message.getBytes(),ip);
        String time = getCurrentTime();                //获取当前时间
        String str = time + " 我对:" + (ip.equals("255.255.255.255") ? "所有人" : ip) + "说\r\n" + message + "\r\n\r\n";    //alt + shift + l 抽取局部变量
        viewText.append(str);                        //将信息添加到显示区域中
        bw.write(str);                                //将信息写到数据库中
        sendText.setText("");
    }
    private String getCurrentTime() {
        Date d = new Date();                        //创建当前日期对象
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
        return sdf.format(d);                        //将时间格式化
    }
    public void centerPanel() {
        Panel center = new Panel();                    //创建中间的Panel
        viewText = new TextArea();
        sendText = new TextArea(5,1);
        center.setLayout(new BorderLayout());        //设置为边界布局管理器
        center.add(sendText,BorderLayout.SOUTH);    //发送的文本区域放在南边
        center.add(viewText,BorderLayout.CENTER);    //显示区域放在中间
        viewText.setEditable(false);                //设置不可以编辑
        viewText.setBackground(Color.WHITE);        //设置背景颜色
        sendText.setFont(new Font("xxx", Font.PLAIN, 15));
        viewText.setFont(new Font("xxx", Font.PLAIN, 15));
        this.add(center,BorderLayout.CENTER);
    }
    public void southPanel() {
        Panel south = new Panel();                    //创建南边的Panel
        tf = new TextField(15);
        tf.setText("127.0.0.1");
        send = new Button("send");
        log = new Button("logs");
        clear = new Button("clear");
        shake = new Button("shake");
        south.add(tf);
        south.add(send);
        south.add(log);
        south.add(clear);
        south.add(shake);
        this.add(south,BorderLayout.SOUTH);            //将Panel放在Frame的南边
    }
    public void init() {
        this.setLocation(500, 50);
        this.setSize(400, 600);
        this.setTitle("聊天室");
        this.setIconImage(Toolkit.getDefaultToolkit().createImage(".\\009网络编程\\weixin.png"));
        new Receive().start();
        try {
            socket = new DatagramSocket();
            File file = new File("db.txt");
            if(!file.exists()){
                file.createNewFile();
            }
            bw = new BufferedWriter(new FileWriter(file,true));    //需要在尾部追加
        } catch (Exception e) {
            e.printStackTrace();
        }
        this.setVisible(true);
    }
    private class Receive extends Thread {            //接收和发送需要同时执行,所以定义成多线程的
        @Override
        public void run() {
            try {
                DatagramSocket socket = new DatagramSocket(9999);
                DatagramPacket packet = new DatagramPacket(new byte[8192], 8192);
                while(true) {
                    socket.receive(packet);                //接收信息
                    byte[] arr = packet.getData();        //获取字节数据
                    int len = packet.getLength();        //获取有效的字节数据
                    if(arr[0] == -1 && len == 1) {        //如果发过来的数组第一个存储的值是-1,并且数组长度是1
                        shake();                        //调用震动方法
                        continue;                        //终止本次循环,继续下次循环,因为震动后不需要执行下面的代码
                    }
                    String message = new String(arr,0,len);    //转换成字符串
                    String time = getCurrentTime();        //获取当前时间
                    String ip = packet.getAddress().getHostAddress();    //获取ip地址
                    String str = time + " " + ip + " 对我说:\r\n" + message + "\r\n\r\n";
                    viewText.append(str);
                    bw.write(str);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    public static void main(String[] args) {
        new Demo04MyGUIChat();
    }
}