How to get parent URL in Java?

Question

In Objective-C I use -[NSURL URLByDeletingLastPathComponent] to get parent URL. What\'s the equivalent of this in Java?

Answer 1

The simple solution offered by Guava library.

Code:

URL url = new URL("https://www.ibm.watson.co.uk");
String host = url.getHost();

InternetDomainName parent = InternetDomainName.from(host).parent(); // returns ibm.watson.co.uk
System.out.println("Immediate ancestor: "+parent);


ImmutableList parts = InternetDomainName.from(host).parts(); 
System.out.println("Individual components:  "+parts);


InternetDomainName name = InternetDomainName.from(host).topPrivateDomain(); // watson.co.uk
System.out.println("Top private domain - " + name);

Output:

Immediate ancestor: ibm.watson.co.uk

Individual components:  [www, ibm, watson, co, uk]

Top private domain - watson.co.uk

For reference: https://guava.dev/releases/snapshot/api/docs/com/google/common/net/InternetDomainName.html

Dependency required:

https://mvnrepository.com/artifact/com.google.guava/guava

I'm using version 19.0

        com.google.guava
        guava

And, many more related functionalities are provided by this class InternetDomainName.