如何在Java中测试互联网的可用性？

import java.net.InetAddress;
import java.net.UnknownHostException;

public class InternetAvailabilityChecker {
    public static void main(String[] args) {
        try {
            InetAddress address = InetAddress.getByName("www.google.com");
            boolean isReachable = address.isReachable(5000); // 设置超时时间为5秒
            if (isReachable) {
                System.out.println("互联网可用");
            } else {
                System.out.println("互联网不可用");
            }
        } catch (UnknownHostException e) {
            System.out.println("无法解析目标地址");
        } catch (IOException e) {
            System.out.println("网络异常");
        }
    }
}

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;

public class InternetAvailabilityChecker {
    public static void main(String[] args) {
        try {
            URL url = new URL("http://www.google.com");
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("HEAD"); // 设置请求方法为HEAD
            connection.setConnectTimeout(5000); // 设置连接超时时间为5秒
            int responseCode = connection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                System.out.println("互联网可用");
            } else {
                System.out.println("互联网不可用");
            }
        } catch (IOException e) {
            System.out.println("网络异常");
        }
    }
}