网络编程

Java模拟UDP聊天

第一阶段

发送端and接收端

发送端

public class UdpReceiveDemo01 {
    public static void main(String[] args) throws Exception {
        DatagramSocket socket = new DatagramSocket(8888);
        //准备数据，控制台读取
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        //循环发送
        while (true){
            //读取控制台的一行数据
            String data = reader.readLine();
            //必须转化成流
            byte[] datas = data.getBytes();
            DatagramPacket packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress("127.0.0.1",9999));
            //发送消息
            socket.send(packet);
            if (data.equals("拜拜")){
                break;
            }
        }
         socket.close();
    }
}

接收端

public class UdpSenderDemo01 {
    public static void main(String[] args) throws Exception {
        //设置端口号
        DatagramSocket socket = new DatagramSocket(9999);
        while (true){
            //准备接收包裹
            byte[] bytes = new byte[1024];
            //设置包
            DatagramPacket packet = new DatagramPacket(bytes,0,bytes.length);
            //阻塞式接收数据包
            socket.receive(packet);
            //断开链接判断
            byte[] data = packet.getData();
            String s = new String(data, 0, data.length);
            System.out.println(s.trim());
            if (s.equals("拜拜")){
                break;
            }

        }
        socket.close();
    }
}

进阶

互为发送端和接收端，这里用到了多线程哦~

接收线程

TalkReceive

public class TalkReceive implements Runnable {
    DatagramSocket socket = null;
    private int port;
    private String msgFrom;

    public TalkReceive(int port, String msgFrom) {
        this.port = port;
        this.msgFrom = msgFrom;
        try {
            //设置端口号
            socket = new DatagramSocket(port);
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {


        while (true) {
            try {
                //准备接收包裹
                byte[] bytes = new byte[4056];
                //设置包
                DatagramPacket packet = new DatagramPacket(bytes, 0, bytes.length);
                //阻塞式接收数据包
                socket.receive(packet);
                //断开链接判断
                byte[] data = packet.getData();
                String s = new String(data, 0, data.length);
                System.out.println(msgFrom + "说：" + s.trim());
                if (s.trim().equals("拜拜")) {
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
        socket.close();
    }
}

发送线程TalkSend

public class TalkSend implements Runnable{
    DatagramSocket socket =null;
    BufferedReader reader =null;
    private int toPort;
    private String toIp;
    private int fromPort;

    public TalkSend(int fromPort,String toIp,int toPort) {
        this.toIp = toIp;
        this.fromPort = fromPort;
        this.toPort = toPort;
        try {
            socket=new DatagramSocket(fromPort);
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {

        //循环发送
        while (true){
            //读取控制台的一行数据

            try {
                //准备数据，控制台读取
                reader = new BufferedReader(new InputStreamReader(System.in));
                String data = reader.readLine();
                //必须转化成流
                byte[] datas = data.getBytes();
                DatagramPacket packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress(this.toIp,this.toPort));
                //发送消息
                socket.send(packet);
                if (data.equals("拜拜")){
                    break;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        socket.close();
    }
}

测试类一

public class TalkTest01 {
    public static void main(String[] args) {
        new Thread(new TalkSend(7777,"127.0.0.1",9999)).start();
        new Thread(new TalkReceive(8888,"老码农")).start();
    }
}

测试类二

public class TalkTest02 {
    public static void main(String[] args) {
        new Thread(new TalkSend(5555,"127.0.0.1",8888)).start();
        new Thread(new TalkReceive(9999,"小码农")).start();
    }
}

对话框

中间遇到了空指针异常，也搞了将近两个小时吧，最后还是写出来了，心里很开心，随着学习的深入，让我发现要走的路还很远，希望每个程序员都能一直走下去！！！，Java有无限魅力！！！