對map key 和Value 排序

對MAP KEY排序 

package study.base.map;
 
import java.util.Comparator;
import java.util.Map;
import java.util.TreeMap;
 
public class SortKeyMap {
    public static void main(String[] args) {
        SortKeyMap sortMap=new SortKeyMap();
        Map<String, Integer> map = new TreeMap<String, Integer>();
        map.put("KFC",123456);
        map.put("WNBA", 4566);
        map.put("NBA", 333);
        map.put("CBA", 44444);
        Map<String, Integer> resultMap = sortMap.sortMapByValue(map); //按Value進行排序
        for (Map.Entry<String, Integer> entry : resultMap.entrySet()) {
            System.out.println(entry.getKey() + " " + entry.getValue());
        }
    }
     
    /**
     * 使用 Map按value進行排序
     * @param map
     * @return
     */
    public Map<String, Integer> sortMapByValue(Map<String, Integer> map) {
        if (map == null || map.isEmpty()) {
            return null;
        }
        Map<String, Integer> sortMap = new TreeMap<String, Integer>(new MapComparator());  
        sortMap.putAll(map);
        return sortMap;
    }
     
    //比較器類
    class MapComparator implements Comparator<String> {
                 
        public int compare(String me1, String me2) {
            return me1.compareTo(me2);
        }
    }
}

對MAP VALUE 排序

package study.base.map;
 
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.TreeMap;
 
public class SortValueMap {
    public static void main(String[] args) {
        SortValueMap sortMap=new SortValueMap();
        Map<String, Integer> map = new TreeMap<String, Integer>();
        map.put("KFC",123456);
        map.put("WNBA", 4566);
        map.put("NBA", 333);
        map.put("CBA", 44444);
        Map<String, Integer> resultMap = sortMap.sortMapByValue(map); //按Value進行排序
        for (Map.Entry<String, Integer> entry : resultMap.entrySet()) {
            System.out.println(entry.getKey() + " " + entry.getValue());
        }
    }
     
    /**
     * 使用 Map按value進行排序
     * @param map
     * @return
     */
    public Map<String, Integer> sortMapByValue(Map<String, Integer> map) {
        if (map == null || map.isEmpty()) {
            return null;
        }
         
        Map<String, Integer> sortedMap = new LinkedHashMap<String, Integer>();
        List<Map.Entry<String, Integer>> entryList = new ArrayList<Map.Entry<String, Integer>>(map.entrySet());
        Collections.sort(entryList, new MapValueComparator());
        Iterator<Map.Entry<String, Integer>> iter = entryList.iterator();
        Map.Entry<String, Integer> tmpEntry = null;
        while (iter.hasNext()) {
            tmpEntry = iter.next();
            sortedMap.put(tmpEntry.getKey(), tmpEntry.getValue());
        }
        return sortedMap;
    }
     
    //比較器類
    class MapValueComparator implements Comparator<Map.Entry<String, Integer>> {
                 
        public int compare(Entry<String, Integer> me1, Entry<String, Integer> me2) {
            return me1.getValue().compareTo(me2.getValue());
        }
    }
}