import java.util.HashMap;import java.util.Iterator;import java.util.Map.Entry;  public class Demo {    public static void main(String[] args) {        HashMap
     
       map = new HashMap
      
       ();        map.put(1,"三国");//值是字符串        map.put("数组",new int[]{1,2,3});//值是数组        map.put(null, null);//值是null        map.put(map,map);//值是map自己        map.put('A',2.8 );//值是浮点数                 Iterator
       
        
         > it = map.entrySet().iterator();        while(it.hasNext()){            Entry
         
           e = it.next();            System.out.println(e.getKey()+","+e.getValue());        }    }}