package chapter6; import java.util.Iterator; import java.util.Set; import java.util.TreeMap; public class Example19 { public static void main(String[] args) { TreeMap map = new TreeMap(); // 创建Map集合 map.put(3, "李四"); // 存储键和值 map.put(2, "王五"); map.put(4, "赵六"); map.put(3, "张三"); Set keySet = map.keySet(); Iterator iterator = keySet.iterator(); while (iterator.hasNext()) { Object key = iterator.next(); Object value = map.get(key); System.out.println(key + ":" + value); } } }