Difference between Comparator and Comparable in Java?

Difference between Comparator and Comparable in Java?

Difference between Comparator and Comparable in Java?

Comparator[I]

• It is present in java.lang package and it contains only one method.
  • [highlight]compareTo()[/highlight];  
• If we are depending on default natural sorting order then while adding the object into the TreeSet JVM will call compareTo() method. 
• • If default natural sorting order not available or if we are not satisfied with natural sorting order then we can go for customized sorting by using the comparator. 
• Comparable meant for default natural sorting order whereas Comparator meant for customized sorting order

package com.java4us;

import java.util.TreeSet;

public class Test {

    public static void main(String[] args) {
        TreeSet t = new TreeSet();
        t.add("A");
        t.add("Z"); // --> "Z".compareTo("A") retrun +ve
        t.add("T"); // --> "T".compareTo("Z") retrun -ve
        System.out.println(t); // [A, T, Z]

    }
}