java/w11/UrlValidator.java

import java.net.MalformedURLException;
import java.net.URL;

public class UrlValidator {
    public static void validateUrl(String urlStr) {
        if (urlStr == null || urlStr.trim().isEmpty()) {
            throw new UrlFormatException("URL不能为空", urlStr);
        }
        
        try {
            new URL(urlStr);
        } catch (MalformedURLException e) {
            throw new UrlFormatException("URL格式无效", e, urlStr);
        }
    }
}