Java获取URL中的顶级域名domain的工具类

方式一：

import java.net.MalformedURLException;
import java.net.URL;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import java.util.regex.Pattern;

public class URLUtil {

    private final static Set<String> PublicSuffixSet = new HashSet<String>(
            Arrays.asList(new String(
                    "com|org|net|gov|edu|co|tv|mobi|info|asia|xxx|onion|cn|com.cn|edu.cn|gov.cn|net.cn|org.cn|jp|kr|tw|com.hk|hk|com.hk|org.hk|se|com.se|org.se")
                    .split("\|")));

    private static Pattern IP_PATTERN = Pattern.compile("(\d{1,3}\.){3}(\d{1,3})");

    /**
     * 获取url的顶级域名
     * @param url
     * @return
     */
    public static String getDomainName(URL url) {
        String host = url.getHost();
        if (host.endsWith(".")){
            host = host.substring(0, host.length() - 1);
        }
        if (IP_PATTERN.matcher(host).matches()){
            return host;
        }

        int index = 0;
        String candidate = host;
        for (; index >= 0;) {
            index = candidate.indexOf('.');
            String subCandidate = candidate.substring(index + 1);
            if (PublicSuffixSet.contains(subCandidate)) {
                return candidate;
            }
            candidate = subCandidate;
        }
        return candidate;
    }

    /**
     * 获取url的顶级域名
     * @param url
     * @return
     * @throws MalformedURLException
     */
    public static String getDomainName(String url) throws MalformedURLException {
        return getDomainName(new URL(url));
    }

    /**
     * 判断两个url顶级域名是否相等
     * @param url1
     * @param url2
     * @return
     */
    public static boolean isSameDomainName(URL url1, URL url2) {
        return getDomainName(url1).equalsIgnoreCase(getDomainName(url2));
    }

    /**
     * 判断两个url顶级域名是否相等
     * @param url1
     * @param url2
     * @return
     * @throws MalformedURLException
     */
    public static boolean isSameDomainName(String url1, String url2)
            throws MalformedURLException {
        return isSameDomainName(new URL(url1), new URL(url2));
    }
    
    public static void main(String[] args) throws Exception {
        String urlStr = "http://news.hexun.com/2017-09-23/190978248.html";
        getDomainName(urlStr);
        getDomainName(new URL(urlStr));
    }

}

方式二：

import java.net.MalformedURLException;
import java.net.URL;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class DomainUtils {
    /**
     * 获取url的顶级域名
     * @param
     * @return
     */
    public static String getTopDomain(String url){
        try{
            //获取值转换为小写
            String host = new URL(url).getHost().toLowerCase();//news.hexun.com
            Pattern pattern = Pattern.compile("[^\.]+(\.com\.cn|\.net\.cn|\.org\.cn|\.gov\.cn|\.com|\.net|\.cn|\.org|\.cc|\.me|\.tel|\.mobi|\.asia|\.biz|\.info|\.name|\.tv|\.hk|\.公司|\.中国|\.网络)");
            Matcher matcher = pattern.matcher(host);
            while(matcher.find()){
                return matcher.group();
            }
        }catch(MalformedURLException e){
            e.printStackTrace();
        }
        return null;
    }
    public static void main(String[] args) {
        System.out.println(getTopDomain("http://news.hexun.com/2017-09-23/190978248.html"));//hexun.com

    }
}