55/URLAccessibleChecker.java

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

public class URLAccessibleChecker {

    public static boolean isURLAccessible(String url) {
        try {
            URL u = new URL(url);
            HttpURLConnection huc = (HttpURLConnection) u.openConnection();
            huc.setRequestMethod("GET");
            huc.setRequestProperty("User-Agent", "Mozilla/5.0");
            huc.setRequestProperty("Accept", "*/*");
            huc.setConnectTimeout(5000); // 5 seconds timeout  
            huc.connect();
            int responseCode = huc.getResponseCode();
            // HTTP OK status returned.  
            return (200 <= responseCode && responseCode <= 399);
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }
    }

    public static void main(String[] args) {
        String testUrl = "http://肥猫.com";
        System.out.println("Is URL accessible? " + isURLAccessible(testUrl));
    }
}