ComparatorExampleForUserDefinedClass.java Source code

Introduction

Here is the source code for ComparatorExampleForUserDefinedClass.java

Source

import org.apache.commons.collections.comparators.ComparatorChain;

import java.util.Arrays;
import java.util.Comparator;

public class ComparatorExampleForUserDefinedClass {
    public static void main(String args[]) {
        prepareData();

        ComparatorChain chain = new ComparatorChain();
        chain.addComparator(new NameComparator());
        chain.addComparator(new NumberComparator());

        printArray(dataArray);

        Arrays.sort(dataArray, chain);

        printArray(dataArray);
    }

    private static void prepareData() {
        dataArray[0] = "S4";
        dataArray[1] = "Sa";
        dataArray[2] = "K";
        dataArray[3] = "K4";
        dataArray[4] = "W";
        dataArray[5] = "Sha";
        dataArray[6] = "War";
    }

    private static void printArray(String[] array) {
        System.err.println("---- Elements in Array ---- ");
        for (int i = 0; i < array.length; i++) {
            System.err.print(array[i] + ", ");
        }
        System.err.println("");
    }

    private static String[] dataArray = new String[7];
}

class NameComparator implements Comparator {
    public int compare(Object o1, Object o2) {
        if (o1 instanceof String && o2 instanceof String) {
            String s1 = (String) o1;
            String s2 = (String) o2;
            s1 = s1.substring(0, s1.indexOf("-"));
            s2 = s2.substring(0, s2.indexOf("-"));
            return s1.compareTo(s2);
        }
        return 0;
    }
}

class NumberComparator implements Comparator {
    public int compare(Object o1, Object o2) {
        if (o1 instanceof String && o2 instanceof String) {
            String s1 = (String) o1;
            String s2 = (String) o2;
            Integer i1 = new Integer(s1.substring(s1.indexOf("-"), s1.length()));
            Integer i2 = new Integer(s2.substring(s2.indexOf("-"), s2.length()));
            return i1.compareTo(i2);
        }
        return 0;
    }
}