map 按value排序

package 

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;

public class MapValueComparator {
	public static void printMap(Map<String, Long> map) {
		Iterator it = map.entrySet().iterator();
		while (it.hasNext()) {
			Map.Entry entry = (Map.Entry) it.next();
			System.out.println(entry.getKey() + ":" + entry.getValue());
		}
	}

	public static Map<String, Long> sortMap(Map<String, Long> oldMap) {
		ArrayList<Map.Entry<String, Long>> list = new ArrayList<Map.Entry<String, Long>>(oldMap.entrySet());
		Collections.sort(list, new Comparator<Map.Entry<String, Long>>() {
			@Override
			public int compare(Entry<java.lang.String, Long> arg0, Entry<java.lang.String, Long> arg1) {
				// return arg0.getValue() - arg1.getValue(); //asc
				return (int) (arg1.getValue() - arg0.getValue()); // desc
			}
		});
		Map<String, Long> newMap = new LinkedHashMap<String, Long>();
		for (int i = 0; i < list.size(); i++) {
			newMap.put(list.get(i).getKey(), list.get(i).getValue());
		}
		return newMap;
	}

	public static void main(String[] args) throws Exception {
		// TODO code application logic here
		Map<String, Long> myMap = new HashMap<String, Long>();
		myMap.put("1", 1l);
		myMap.put("2", 4l);
		myMap.put("3", 3l);
		myMap.put("4", 9l);
		myMap.put("5", 6l);
		myMap.put("6", 2l);
		myMap = sortMap(myMap);
		printMap(myMap);
	}

}