Java Comparator for PriorityQueue

// how to implement self-defined priorityqueue comparator in java
/**
 * @author lautturi.com 
 * Java example: custom Comparator for PriorityQueue in java
 */

import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.*;

class stringLenComparator implements Comparator<String> {

	public int compare(String s1, String s2) {
		if (s1.length() > s2.length())
			return -1;
		else if (s1.length() < s2.length())
			return 1;
		else
			return 0;
	}
}

public class Lautturi {
	public static void main(String[] args) throws IOException {

		PriorityQueue<String> prq = new PriorityQueue<>(new stringLenComparator());

		// insert values to the queue
		prq.add("python");
		prq.add("hello");
		prq.add("js");
		prq.add("php");
		prq.add("perl");
		prq.add("world");
		
		//print the PriorityQueue
        while (!prq.isEmpty()) {
            System.out.println(prq.poll()+" ");
        }

	}
}

output:

python 
hello 
world 
perl 
php 
js