Java NIO

public static void main(String[] args) throws IOException, InterruptedException {

    LinkedList<SocketChannel> clients = new LinkedList<>();
    ServerSocketChannel ss = ServerSocketChannel.open();
    ss.bind(new InetSocketAddress(9090));
    ss.configureBlocking(false);
    while (true) {
        Thread.sleep(1000L);
        // 非阻塞
        SocketChannel client = ss.accept();
        if (client == null) {
            System.err.println("client is null");
        } else {
            client.configureBlocking(false);
            int port = client.socket().getPort();
            System.err.println("client port " + port);
            clients.add(client);
        }

        ByteBuffer byteBuffer = ByteBuffer.allocateDirect(4096);

        // 串型话
        // 真实场景下 每一个client一个独自的buffer
        for (SocketChannel c : clients) {
            // -1 出现空轮训 
            int num = c.read(byteBuffer);
            if (num > 0) {
                byteBuffer.flip();
                byte[] aaa = new byte[byteBuffer.limit()];
                byteBuffer.get(aaa);

                String b = new String(aaa);
                System.err.println(c.socket().getPort() + " :   " + b);
                // 清空 循环下一次client在使用
                byteBuffer.clear();
            }
        }
    }
}