vn.vitk-master/src/main/java/vn/vitk/util/MapUtil.java
package vn.vitk.util;

import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

public class MapUtil {
	
	/**
	 * Sorts a map by value.
	 * @param map
	 * @return a map whose values are sorted.
	 */
	public static <K, V extends Comparable<? super V>> Map<K, V> sortByValue(Map<K, V> map) {
		List<Map.Entry<K, V>> list = new LinkedList<Map.Entry<K, V>>(map.entrySet());
		Collections.sort(list, new Comparator<Map.Entry<K, V>>() {
			public int compare(Map.Entry<K, V> o1, Map.Entry<K, V> o2) {
				return -(o1.getValue()).compareTo(o2.getValue());
			}
		});

		Map<K, V> result = new LinkedHashMap<K, V>();
		for (Map.Entry<K, V> entry : list) {
			result.put(entry.getKey(), entry.getValue());
		}
		return result;
	}
}
