Java 用于检索 domain.tld 的正则表达式
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Regular expression to retrieve domain.tld
提问by sjobe
I'm need a regular expression in Java that I can use to retrieve the domain.tld part from any url. So https://foo.com/bar, http://www.foo.com#bar, http://bar.foo.comwill all return foo.com.
我需要一个 Java 中的正则表达式，我可以用它来从任何 url 检索 domain.tld 部分。所以https://foo.com/bar, http://www.foo.com#bar, http://bar.foo.com都会返回 foo.com 。
I wrote this regex, but it's matching the whole url
我写了这个正则表达式，但它匹配整个 url
Pattern.compile("[.]?.*[.x][a-z]{2,3}");
I'm not sure I'm matching the "." character right. I tried "." but I get an error from netbeans.
我不确定我是否匹配“。” 性格对。我试过 ”。” 但我从 netbeans 收到错误消息。
Update:
更新：
The tld is not limited to 2 or 3 characters, and http://www.foo.co.uk/barshould return foo.co.uk.
tld 不限于 2 或 3 个字符，http://www.foo.co.uk/bar应返回 foo.co.uk。
采纳答案by idrosid
I would use the java.net.URI class to extract the host name, and then use a regex to extract the last two parts of the host uri.
我会使用 java.net.URI 类来提取主机名，然后使用正则表达式来提取主机 uri 的最后两部分。
import java.net.URI;
import java.net.URISyntaxException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RunIt {
public static void main(String[] args) throws URISyntaxException {
Pattern p = Pattern.compile(".*?([^.]+\.[^.]+)");
String[] urls = new String[] {
"https://foo.com/bar",
"http://www.foo.com#bar",
"http://bar.foo.com"
};
for (String url:urls) {
URI uri = new URI(url);
//eg: uri.getHost() will return "www.foo.com"
Matcher m = p.matcher(uri.getHost());
if (m.matches()) {
System.out.println(m.group(1));
}
}
}
}
Prints:
印刷：
foo.com
foo.com
foo.com
回答by jsamsa
This is harder than you might imagine. Your example https://foo.com/bar, has a comma in it, which is a valid URL character. Here is a great post about some of the troubles:
这比你想象的要难。您的示例https://foo.com/bar中包含一个逗号，这是一个有效的 URL 字符。这是一篇关于一些麻烦的好文章：
https://blog.codinghorror.com/the-problem-with-urls/
https://blog.codinghorror.com/the-problem-with-urls/
https?://([-A-Za-z0-9+&@#/%?=~_()|!:,.;]*[-A-Za-z0-9+&@#/%=~_()|])
Is a good starting point
是一个很好的起点
Some listings from "Mastering Regular Expressions" on this topic:
“掌握正则表达式”中关于此主题的一些列表：
http://regex.info/listing.cgi?ed=3&p=207
http://regex.info/listing.cgi?ed=3&p=207
@sjobe
@sjobe
>>> import re
>>> pattern = r'https?://([-A-Za-z0-9+&@#/%?=~_()|!:,.;]*[-A-Za-z0-9+&@#/%=~_()|])'
>>> url = re.compile(pattern)
>>> url.match('http://news.google.com/').groups()
('news.google.com/',)
>>> url.match('not a url').groups()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'groups'
>>> url.match('http://google.com/').groups()
('google.com/',)
>>> url.match('http://google.com').groups()
('google.com',)
sorry the example is in python not java, it's more brief. Java requires some extraneous escaping of the regex.
对不起，这个例子是在python而不是java中，它更简短。Java 需要对正则表达式进行一些无关的转义。
回答by Adam Pope
You're going to need to get a list of all possible TLDs and ccTLDs and then match against them. You have to do this else you'll never be able to distinguish between subdomain.dom.com and hello.co.uk.
您将需要获得所有可能的 TLD 和 ccTLD 的列表，然后与它们进行匹配。您必须这样做，否则您将永远无法区分 subdomain.dom.com 和 hello.co.uk。
So, get your self such a list. I recommend inverting it so you store, for example, uk.co. Then, you can extract the domain from a URL by getting everying between // and / or end of line. Split at . and work backwards, matching the TLD and then 1 additional level to get the domain.
所以，给你自己一个这样的清单。我建议将其反转以便存储，例如 uk.co。然后，您可以通过获取 // 和 / 或行尾之间的所有内容从 URL 中提取域。拆分于 。并反向工作，匹配 TLD，然后再增加 1 个级别以获得域。
回答by Qtax
If the string contains a valid URL then you could use a regex like (Perl quoting):
如果字符串包含有效的 URL，那么您可以使用像（Perl 引用）这样的正则表达式：
/^
(?:\w+:\/\/)?
[^:?#\/\s]*?
(
[^.\s]+
\.(?:[a-z]{2,}|co\.uk|org\.uk|ac\.uk|org\.au|com\.au|___etc___)
)
(?:[:?#\/]|$)
/xi;
Results:
结果：
url: https://foo.com/bar
matched: foo.com
url: http://www.foo.com#bar
matched: foo.com
url: http://bar.foo.com
matched: foo.com
url: ftp://foo.com
matched: foo.com
url: ftp://www.foo.co.uk?bar
matched: foo.co.uk
url: ftp://www.foo.co.uk:8080/bar
matched: foo.co.uk
For Java it would be quoted something like:
对于 Java，它会被引用如下：
"^(?:\w+://)?[^:?#/\s]*?([^.\s]+\.(?:[a-z]{2,}|co\.uk|org\.uk|ac\.uk|org\.au|com\.au|___etc___))(?:[:?#/]|$)"
Of course you'll need to replace the etcpart.
当然，您需要更换等部件。
Example Perl script:
Perl 脚本示例：
use strict;
my @test = qw(
https://foo.com/bar
http://www.foo.com#bar
http://bar.foo.com
ftp://foo.com
ftp://www.foo.co.uk?bar
ftp://www.foo.co.uk:8080/bar
);
for(@test){
print "url: $_\n";
/^
(?:\w+:\/\/)?
[^:?#\/\s]*?
(
[^.\s]+
\.(?:[a-z]{2,}|co\.uk|org\.uk|ac\.uk|org\.au|com\.au|___etc___)
)
(?:[:?#\/]|$)
/xi;
print "matched: \n";
}
回答by Amy B
new URL(url).getHost()
new URL(url).getHost()
No regex needed.
不需要正则表达式。
回答by mel
回答by tomisyourname
This works for me:
这对我有用：
public static String getDomain(String url){
if(TextUtils.isEmpty(url)) return null;
String domain = null;
if(url.startsWith("http://")) {
url = url.replace("http://", "").trim();
} else if(url.startsWith("https://")) {
url = url.replace("https://", "").trim();
}
String[] temp = url.split("/");
if(temp != null && temp.length > 0) {
domain = temp[0];
}
return domain;
}
回答by Yeongjun Kim
Code:
代码：
public class DomainUrlUtils {
private static String[] TLD = {"com", "net"}; // top-level domain
private static String[] SLD = {"co\.kr"}; // second-level domain
public static String getDomainName(String url) {
Pattern pattern = Pattern.compile("(?<=)[^(\.|\/)]\w+\.(" + joinTldAndSld("|") + ")$");
Matcher match = pattern.matcher(url);
String domain = null;
if (match.find()) {
domain = match.group();
}
return domain;
}
private static String joinTldAndSld(String delimiter) {
String t = String.join(delimiter, TLD);
String s = String.join(delimiter, SLD);
return new StringBuilder(t).append(s.isEmpty() ? "" : "|" + s).toString();
}
}
Test:
测试：
public class DomainUrlUtilsTest {
@Test
public void getDomainName() throws Exception {
// given
String[][] domainUrls = {
{
"test.com",
"sub1.test.com",
"sub1.sub2.test.com",
"https://sub1.test.com",
"http://sub1.sub2.test.com"
},
{
"https://domain.com",
"https://sub.domain.com"
},
{
"http://domain.co.kr",
"http://sub.domain.co.kr",
"http://local.sub.domain.co.kr",
"http://local-test.sub.domain.co.kr",
"sub.domain.co.kr",
"domain.co.kr",
"test.sub.domain.co.kr"
}
};
String[] expectedUrls = {
"test.com",
"domain.com",
"domain.co.kr"
};
// when
// then
for (int domainIndex = 0; domainIndex < domainUrls.length; domainIndex++) {
for (String url : domainUrls[domainIndex]) {
String convertedUrl = DomainUrlUtils.getDomainName(url);
if (expectedUrls[domainIndex].equals(convertedUrl)) {
System.out.println(url + " -> " + convertedUrl);
} else {
Assert.fail("origin Url: " + url + " / converted Url: " + convertedUrl);
}
}
}
}
}
Results:
结果：
test.com -> test.com
sub1.test.com -> test.com
sub1.sub2.test.com -> test.com
https://sub1.test.com -> test.com
http://sub1.sub2.test.com -> test.com
https://domain.com -> domain.com
https://sub.domain.com -> domain.com
http://domain.co.kr -> domain.co.kr
http://sub.domain.co.kr -> domain.co.kr
http://local.sub.domain.co.kr -> domain.co.kr
http://local-test.sub.domain.co.kr -> domain.co.kr
sub.domain.co.kr -> domain.co.kr
