Java 函数中 NIO 技术如何应用于分布式系统？

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.nio.charset.StandardCharsets;
import java.util.Iterator;

public class MessageConsumer {

    private static final String HOST = "localhost";
    private static final int PORT = 8080;
    private static final String TOPIC = "messages";

    public static void main(String[] args) throws IOException {
        // 创建一个选择器
        Selector selector = Selector.open();

        // 打开一个连接
        SocketChannel socketChannel = SocketChannel.open();
        socketChannel.configureBlocking(false);
        socketChannel.connect(new InetSocketAddress(HOST, PORT));

        // 注册输入兴趣
        socketChannel.register(selector, Selector.OP_READ);

        // 持续读取消息
        while (true) {
            // 阻塞直到有 I/O 操作就绪
            selector.select();

            // 获取已准备就绪的通道
            Iterator<SelectionKey> iterator = selector.selectedKeys().iterator();

            // 处理已就绪的通道
            while (iterator.hasNext()) {
                SelectionKey key = iterator.next();
                iterator.remove();

                if (key.isReadable()) {
                    // 读取消息
                    ByteBuffer buffer = ByteBuffer.allocate(1024);
                    socketChannel.read(buffer);
                    String message = new String(buffer.array(), StandardCharsets.UTF_8);

                    // 处理消息
                    System.out.println("Received message: " + message);
                }
            }
        }
    }
}