对map进行排序

public class TreeMapTest {
    public static void main(String[] args)
{
        Map<String, String> map = new TreeMap<String,
String>(
                new Comparator<String>()
{
                    public int compare(String obj1, String obj2)
{
                        // 降序排序
                        return
obj2.compareTo(obj1);
                    }
                });
       
map.put("c", "ccccc");
        map.put("a", "aaaaa");
        map.put("b",
"bbbbb");
        map.put("d", "ddddd");

Set<String>
keySet = map.keySet();
        Iterator<String> iter =
keySet.iterator();
        while (iter.hasNext()) {
            String key
= iter.next();
            System.out.println(key + ":" +
map.get(key));
        }
    }
}