java_Hashtable和Enumeration用法

public static void main(String arg0[])
{

Hashtable hash=new Hashtable();
hash.put( "abc","1");
hash.put("ddd","1");
hash.put( "asdf","2");
Enumeration enumkey = hash.keys() ;
while(enumkey.hasMoreElements()){
String str=(String)enumkey.nextElement();
System.out.println("--------"+str);
System.out.println("========="+hash.get( str));
if("1".equals(hash.get( str)))
hash.remove( str);
}
System.out.println("-ssssssssssssssssssss-"+hash.get( "asdf"));
enumkey = hash.keys() ;
while(enumkey.hasMoreElements()){
String str=(String)enumkey.nextElement();
System.out.println("--------"+str);
System.out.println("========="+hash.get( str));
}
}