URL stands for Uniform resource locator, it is a special type of uri which tells how to access the resource.
Example
https://self-learning-java-tutorial.blogspot.com/search?q=test
In the above example.
https -> specific scheme
self-learning-java-tutorial.blogspot.com -> represents the path
/search -> specifies the path
q=test -> specifies query parameter.
Example 2
https://www.self-learning-java-tutorial.blogspot.com/search?q=test
In the above example, url contains the string www after //.
We need to address both the examples while finding the domain name. Below snippet takes an url and return the domain name.
public static String getHostName(String url) throws URISyntaxException {
URI uri = new URI(url);
String hostComponent = uri.getHost();
return hostComponent.startsWith("www.") ? hostComponent.substring(4) : hostComponent;
}
Find the below working application.
DomainNameDemo.java
package com.sample.app.net;
import java.net.URI;
import java.net.URISyntaxException;
public class DomainNameDemo {
public static String getHostName(String url) throws URISyntaxException {
URI uri = new URI(url);
String hostComponent = uri.getHost();
return hostComponent.startsWith("www.") ? hostComponent.substring(4) : hostComponent;
}
public static void main(String args[]) throws URISyntaxException {
String url1 = "https://self-learning-java-tutorial.blogspot.com/2014/02/blog-post.html";
String url2 = "http://self-learning-java-tutorial.blogspot.com/2014/02/blog-post.html";
String url3 = "https://www.self-learning-java-tutorial.blogspot.com/2014/02/blog-post.html";
String url4 = "http://www.self-learning-java-tutorial.blogspot.com/2014/02/blog-post.html";
System.out.println("Host name in " + url1 + " is \t" + getHostName(url1));
System.out.println("Host name in " + url2 + " is \t\t" + getHostName(url2));
System.out.println("Host name in " + url3 + " is \t" + getHostName(url3));
System.out.println("Host name in " + url4 + " is \t" + getHostName(url4));
}
}
Output
Host name in https://self-learning-java-tutorial.blogspot.com/2014/02/blog-post.html is self-learning-java-tutorial.blogspot.com Host name in http://self-learning-java-tutorial.blogspot.com/2014/02/blog-post.html is self-learning-java-tutorial.blogspot.com Host name in https://www.self-learning-java-tutorial.blogspot.com/2014/02/blog-post.html is self-learning-java-tutorial.blogspot.com Host name in http://www.self-learning-java-tutorial.blogspot.com/2014/02/blog-post.html is self-learning-java-tutorial.blogspot.com
