网络通信(群聊)

// 发送者;消息的内容;接受者(协议)
//多线程的使用
//什么是协议
// 服务端 (群聊)
public class Selever {
//存储socket 名字:socket
static ArrayList<Socket> list = new ArrayList<Socket>();
public static void main(String[] args) throws Exception {
// 创建服务器socket
ServerSocket server = new ServerSocket(8080);
System.out.println("服务器等待接收中。。。。");
// 接收到客户端socket

    while (true) {
        Socket socket = server.accept();//会阻塞
        System.out.println("服务器接受到客户端请求.....");
        //开启线程,接受socket的输入
        SeverListRunnable list = new SeverListRunnable();
        list.socket = socket;
        Thread read = new Thread(list);
        read.start();
}

}
}

class ServerRunnable implements Runnable {
Scanner sc = new Scanner(System.in

);
Socket socket;

@Override
public void run() {
    // 发送消息
    // 给客户端回复
    OutputStream stream = null;
    try {
        while (true) {
            stream = socket.getOutputStream();
            // System.out.println("请输入：");
            String str1 = sc.next();
            stream.write(str1.getBytes());
        }

    } catch (IOException e) {

        e.printStackTrace();
    }

}

}
//接受用户的输入
class SeverListRunnable implements Runnable{
Socket socket ;
@Override
public void run() {
try {
InputStream stream = socket.getInputStream();
while (true) {
byte[] by = new byte[1024];
int length = stream.read(by);
String str = new String(by, 0, length);
//1.谁发送的2.发送的消息3.发送给谁
//解析字符串
String[] arr = str.split(";");
//发送者
String from = arr[0];
//消息
String msg = arr[1];
//接受者
String to = arr[2];
//判断list里是否包含这个人
if (!(Selever.list.contains(from))) {
Selever.list.add(socket);
}
for (Socket item : Selever.list) {
OutputStream out = item.getOutputStream();
out.write(str.getBytes());
}
}
} catch (IOException e) {
e.printStackTrace();
System.out.println("io流异常");
}
}
}

public class Client {
//客户端

    public static void main(String[] args) throws Exception {
        Socket socket = new Socket("172.18.26.191", 8080);

        ClientRunnable run = new ClientRunnable();
        run.socket = socket;
        Thread thread = new Thread(run);
        thread.start();

        // 客户端读出服务器回复的消息
        InputStream in = socket.getInputStream();
        while (true) {
            byte[] by = new byte[1024];
            int length = in.read(by);
            String str1 = new String(by, 0, length);
            String[] arr = str1.split(";");
            String from = arr[0];
            String msg = arr[1];
            String to = arr[2];
            System.out.println(from+":"+msg);
            System.out.println("服务器回复的消息:" + str1);
        }
    }
}
class ClientRunnable implements Runnable {
    Scanner sc = new Scanner(System.in);
    Socket socket;

    @Override
    public void run() {

        try {
            // 客户端端口号 写出请求
            OutputStream stream = socket.getOutputStream();
            while (true) {
                System.out.println("客户端输入(from;msg;to)");
                String str = sc.next();
                stream.write(str.getBytes());
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}