Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

public class Main {
    /**
     * Sort a map according to its values in ascending order when asc=true and i descending order otherwise.
     * @param unsortedMap 
     * @param asc
     * @return
     */
    public static Map<String, Integer> sortUsingComparator(Map<String, Integer> unsortedMap, final boolean asc) {

        // Convert Map to List
        List<Map.Entry<String, Integer>> list = new LinkedList<Map.Entry<String, Integer>>(unsortedMap.entrySet());

        // Sort a list using custom comparator, to compare the Map values
        Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {
            public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) {
                if (asc) {
                    return (o1.getValue()).compareTo(o2.getValue());
                } else {
                    return -1 * (o1.getValue()).compareTo(o2.getValue());
                }
            }
        });

        // Convert the sorted map back to a Map
        Map<String, Integer> sortedMap = new LinkedHashMap<String, Integer>();
        for (Iterator<Map.Entry<String, Integer>> it = list.iterator(); it.hasNext();) {
            Map.Entry<String, Integer> entry = it.next();
            sortedMap.put(entry.getKey(), entry.getValue());
        }
        return sortedMap;
    }
}