Map按Value排序

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


public class Test
{
public static void main(String[] args)
{
 
 Map<String,String> maps = new HashMap<String,String>();
	maps.put("3", "9王五"); 
    maps.put("1", "8张三");
    maps.put("2", "8李四");
    maps.put("4", "6赵六");
    maps = sortByValue(maps);
    Iterator it = maps.entrySet().iterator();

    while (it.hasNext()) {

    Map.Entry pairs = (Map.Entry) it.next();

    System.out.println(pairs.getValue());

    }
}
public static Map sortByValue(Map<String, String> map) {
    List list = new LinkedList(map.entrySet());
    Collections.sort(list, new Comparator(){
           public int compare(Object o1, Object o2) {
                     return ((Comparable) ((Map.Entry)o1).getValue())
                        .compareTo(((Map.Entry)o2).getValue());
           }
    });
    Map result = new LinkedHashMap();

    for (Iterator it = list.iterator(); it.hasNext();) {
          Map.Entry entry = (Map .Entry) it.next();
          result.put(entry.getKey(), entry.getValue());
    }
    return result;

}

public static Map sortByValue(Map map, final boolean reverse) {
        List list = new LinkedList(map.entrySet());
        Collections .sort(list, new Comparator() {
            public int compare(Object o1, Object o2) {
                if (reverse) {
                    return -((Comparable) ((Map .Entry)o1).getValue())
                            .compareTo(((Map .Entry)o2).getValue());
                }
                return ((Comparable) ((Map .Entry)o1).getValue())
                        .compareTo(((Map .Entry)o2).getValue());
            }
        });

        Map result = new LinkedHashMap();
        for (Iterator it = list.iterator(); it.hasNext();) {
            Map.Entry entry = (Map.Entry) it.next();
           result.put(entry.getKey(), entry.getValue());
        }
        return result;
}}

评论

1 楼 rooi 2011-12-24  

int size = maps.size();
      int count = 0;
      Set set = maps.keySet();
      Iterator iter = set.iterator();
      while(iter.hasNext()){
        Object key = iter.next();
        if(count >= (size-2)){
           System.out.println(key+" "+maps.get(key));
        }
        count++;
      }