Java | API to get protocol://domain.port from URL

Question

I have got URL as referrer and want to get protocol and domain from it.

For example: If URL is https://test.domain.com/a/b/c.html?test=hello then output needs to be https://test.domain.com. I have gone through http://docs.oracle.com/javase/7/docs/api/java/net/URI.html and I can't seems to find any method that can directly do so.

I am not using Spring, so can't use Sprint classes (if any).

Guys I can write custom login to get port, domain and protocol from URL, but looking for API which already has this implemented and can minimize my time in testing various scenarios.

possible duplicate of [ Get domain name from given url](http://stackoverflow.com/questions/9607903/get-domain-name-from-given-url) — Subodh Joshi, Aug 20 '15 at 09:13
Look for [java.net.Url](http://docs.oracle.com/javase/7/docs/api/java/net/URL.html) — Jens, Aug 20 '15 at 09:15
URL info might helpyou out. https://docs.oracle.com/javase/tutorial/networking/urls/urlInfo.html — Suresh Atta, Aug 20 '15 at 09:15
@sᴜʀᴇsʜᴀᴛᴛᴀ Same who given right to you comment :) — Subodh Joshi, Aug 20 '15 at 09:18
@sᴜʀᴇsʜᴀᴛᴛᴀ Sorry brother i put wrong url that time so edited it May be due to Copy-Paste issue. — Subodh Joshi, Aug 20 '15 at 09:21
thanks @SubodhJoshi, but as I said I am looking for API's like URL or URI that can do so. — Rupesh, Aug 20 '15 at 09:23
@Rupesh then please change the question title it will make clear picture — Subodh Joshi, Aug 20 '15 at 09:25
possible duplicate of [Issues using Spring's DomainClassConverter in Spring MVC](http://stackoverflow.com/questions/20695180/issues-using-springs-domainclassconverter-in-spring-mvc) — bytecode77, Aug 20 '15 at 10:05
Please check this http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/net/InternetDomainName.html is it will help you — Subodh Joshi, Aug 20 '15 at 10:19

score 22 · Answer 1 · answered Oct 11 '18 at 08:13

22

To elaborate on what @Rupesh mentioned in @mthmulders answer,

getAuthority() gives both domain and port. So you just concatenate it with getProtocol() as prefix:

URL url = new URL("https://test.domain.com/a/b/c.html?test=hello");
String protocol = url.getProtocol();
String authority = url.getAuthority();
return String.format("%s://%s", protocol, authority);

answered Oct 11 '18 at 08:13

Cardin

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If someone like me just want the URL without host name and port then use `url.getPath()` – Kapil Jan 20 '20 at 10:21

score 14 · Accepted Answer · edited Sep 18 '17 at 11:46

14

Create a new URL object using your String value and call getHost() or any other method on it, like so:

URL url = new URL("https://test.domain.com/a/b/c.html?test=hello");
String protocol = url.getProtocol();
String host = url.getHost();
int port = url.getPort();

// if the port is not explicitly specified in the input, it will be -1.
if (port == -1) {
    return String.format("%s://%s", protocol, host);
} else {
    return String.format("%s://%s:%d", protocol, host, port);
}

edited Sep 18 '17 at 11:46

user987339

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answered Aug 20 '15 at 09:16

mthmulders

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this will not work if url is `https://test.domain.com:80/a/b/c.html?test=hello` the output should be `https://test.domain.com:80`. I can write these logic but looking for tried and tested API – Rupesh Aug 20 '15 at 09:20
1

port check is not needed, getAuthority gives domain and port – Rupesh Aug 20 '15 at 09:48
1

you must change if condition : if (port == -1) – Mohse Soodkhah Mohammadi Sep 04 '17 at 13:16
Worked for me. But instead of this multi line approach, I prefer getAuthority() which does the same job in single line. – vinsinraw Jan 14 '20 at 06:17

score -1 · Answer 3 · answered Jan 14 '20 at 06:11

getAuthority() returns the host along with the port but getHost() returns only the host name. So if URL is "https://www.hello.world.com:80/x/y/z.html?test=hello", then getAuthority() return www.hello.world.com:80 while getHost() returns www.hello.world.com

Example

URL url = new URL("https://www.hello.world.com:80/x/y/z.html?test=hello");
String protocol = url.getProtocol();
String host = url.getHost();
int port = url.getPort();
String authority = url.getAuthority();

System.out.println("Host "+host);   // www.hello.world.com
System.out.println("authority "+authority);   // www.hello.world.com:80

//Determining Protocol plus host plus port (if any) url using Authority (simple single line step)
System.out.println("ProtocolHostPortURL:: "+ String.format("%s://%s", protocol, authority));

//Determining Protocol plus host plus port (if any) url using Authority (multi line step)
//If the port is not explicitly specified in the input, it will be -1.
if (port == -1) {
    System.out.println("ProtocolHostURL1:: "+ String.format("%s://%s", protocol, host));        
} else {
    System.out.println("ProtocolHostPortURL2:: "+ String.format("%s://%s:%d", protocol, host, port));    
}

Java | API to get protocol://domain.port from URL

3 Answers3