Java ネットワーク タイムアウト例外 (NetworkTimeoutException) を解決する方法

import java.net.InetAddress;

public class NetworkUtil {
    public static boolean isReachable(String ipAddress, int timeout) {
        try {
            InetAddress address = InetAddress.getByName(ipAddress);
            return address.isReachable(timeout);
        } catch (Exception e) {
            return false;
        }
    }
}

import java.net.Socket;
import java.net.InetSocketAddress;

public class ConnectionUtil {
    public static void connect(String host, int port, int timeout) {
        try {
            Socket socket = new Socket();
            socket.connect(new InetSocketAddress(host, port), timeout);
            socket.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.net.HttpURLConnection;
import java.net.URL;

public class ConnectionManager {
    private static ExecutorService connectionPool = Executors.newFixedThreadPool(10);
    
    public static void sendRequest(String url) {
        connectionPool.submit(() -> {
            try {
                HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
                connection.setRequestMethod("GET");
                connection.setConnectTimeout(5000);
                connection.setReadTimeout(5000);
                
                // 处理响应结果
                
                connection.disconnect();
            } catch (Exception e) {
                e.printStackTrace();
            }
        });
    }
}