java.net.URL obstacles with URL.equals

CanonicalURLs.java

package issue.java.net.url;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.LinkedHashSet;
import java.util.Set;

public class CanonicalURLs {

	public static void main(String[] args) {
		try {
			Set<URL> set = new LinkedHashSet<>();
			set.add(new URL("http://peterkir.github.io/"));
			set.add(new URL("http://square.github.io/"));
			set.add(new URL("http://Square.GitHub.io/"));
			set.add(new URL("http://square.github.io:80/"));
			set.add(new URL("http://google.github.io/"));
			System.out.println(set); // prints only "http://peterkir.github.io/"
		} catch (MalformedURLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

output is only the following (cause they are the same for Java)

[http://peterkir.github.io/]