JAVA-MANI.BLOGSPOT.COM

This example shows you how we can sort items of an ArrayList using the Collections.sort() methods. Beside accepting the list object to be sorted we can also pass a Comparator implementation to define the sorting behavior.


package org.kodejava.example.util;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

public class ArrayListSortExample {
public static void main(String[] args) {
/*
* Create a collections of colours
*/
List colours = new ArrayList();
colours.add("red");
colours.add("green");
colours.add("blue");
colours.add("yellow");
colours.add("cyan");
colours.add("white");
colours.add("black");

/*
* We can sort items of a list using the Collections.sort() method.
* We can also reverse the order of the sorting by passing the
* Collections.reverseOrder() comparator.
*/
Collections.sort(colours);
System.out.println(Arrays.toString(colours.toArray()));

Collections.sort(colours, Collections.reverseOrder());
System.out.println(Arrays.toString(colours.toArray()));
}
}



The code will output:

[black, blue, cyan, green, red, white, yellow]
[yellow, white, red, green, cyan, blue, black]