从给定的URL中提取主域名 [英] Extract main domain name from a given url

问题描述

我使用以下内容从网址中提取域:(它们是测试用例）

I used the following to extract the domain from a url: (They are test cases)

String regex = "^(ww[a-zA-Z0-9-]{0,}\\.)";
ArrayList<String> cases = new ArrayList<String>();
cases.add("www.google.com");
cases.add("ww.socialrating.it");
cases.add("www-01.hopperspot.com");
cases.add("wwwsupernatural-brasil.blogspot.com");
cases.add("xtop10.net");
cases.add("zoyanailpolish.blogspot.com");

for (String t : cases) {  
    String res = t.replaceAll(regex, "");  
}

我可以得到以下结果：

google.com
hopperspot.com
socialrating.it
blogspot.com
xtop10.net
zoyanailpolish.blogspot.com

前四种情况都不错。最后一个不好。我想要的是： blogspot.com 最后一个，但它给出了 zoyanailpolish.blogspot.com 。我做错了什么？

The first four cases are good. The last one is not good. What I want is: blogspot.com for the last one, but it gives zoyanailpolish.blogspot.com. What am I doing wrong?

推荐答案

正如BalusC和其他人所建议的那样，最实际的解决方案是获取TLD列表（请参阅此列表），将其保存到文件中，加载它们，然后确定TLD是什么由给定的url字符串使用。从那里你可以构成主域名，如下所示：

As suggested by BalusC and others the most practical solution would be to get a list of TLDs (see this list), save them to a file, load them and then determine what TLD is being used by a given url String. From there on you could constitute the main domain name as follows:

    String url = "zoyanailpolish.blogspot.com";

    String tld = findTLD( url ); // To be implemented. Add to helper class ?

    url = url.replace( "." + tld,"");  

    int pos = url.lastIndexOf('.');

    String mainDomain = "";

    if (pos > 0 && pos < url.length() - 1) {
        mainDomain = url.substring(pos + 1) + "." + tld;
    }
    // else: Main domain name comes out empty

实施细节留给你。

这篇关于从给定的URL中提取主域名的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！