在实现一个基于Java NIO的服务器时，如何设计线程模型以达到最佳性能？

import java.nio.channels.*;
import java.nio.*;
import java.net.*;
import java.io.*;
import java.util.concurrent.*;

public class NIOReactorServer {
    private static final int PORT = 8080;
    private static final ExecutorService workerPool = Executors.newFixedThreadPool(4);

    public static void main(String[] args) throws Exception {
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.bind(new InetSocketAddress(PORT));
        serverSocketChannel.configureBlocking(false);

        Selector selector = Selector.open();
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);

        while (true) {
            if (selector.select() > 0) {
                for (SelectionKey key : selector.selectedKeys()) {
                    if (key.isAcceptable()) {
                        // 接受客户端连接
                        SocketChannel clientChannel = ((ServerSocketChannel) key.channel()).accept();
                        clientChannel.configureBlocking(false);
                        clientChannel.register(selector, SelectionKey.OP_READ);
                    } else if (key.isReadable()) {
                        // 处理可读事件
                        SocketChannel clientChannel = (SocketChannel) key.channel();
                        workerPool.submit(() -> handleClient(clientChannel));
                    }
                    selector.selectedKeys().remove(key);
                }
            }
        }
    }

    private static void handleClient(SocketChannel clientChannel) {
        try {
            ByteBuffer buffer = ByteBuffer.allocate(1024);
            int bytesRead = clientChannel.read(buffer);
            if (bytesRead == -1) {
                clientChannel.close();
            } else {
                buffer.flip();
                // 处理客户端请求（例如解析数据、生成响应等）
                String response = "Hello from server!";
                buffer.clear();
                buffer.put(response.getBytes());
                buffer.flip();
                clientChannel.write(buffer);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}