将Map中的值拷贝到另一个Map中

public static void main(String[] args) {
	//造数
    Map<String,Object> paramMap=new HashMap<String,Object>();
	paramMap.put("name", "name");
	paramMap.put("nick", "nick");
	paramMap.put("pass", "pass");
	paramMap.put("tel", "tel");
	paramMap.put("email", "email");
		
	Map<String,Object> resultMap=new HashMap<String,Object>();
		
	//开始从paramMap中复制到resultMap中
	Iterator it=paramMap.entrySet().iterator();
	while(it.hasNext()) {
		Map.Entry entry=(Map.Entry)it.next();
		Object key=entry.getKey();
		if(key!=null && paramMap.get(key)!=null) {
			resultMap.put(key.toString(), paramMap.get(key));
		}
	}
	//执行结束
	System.out.println(resultMap.size());
}