//使用迭代器,获取key;  
        /*Iterator<String> iter = map.keySet().iterator(); 
        while(iter.hasNext()){ 
            String key=iter.next(); 
            String value = map.get(key); 
            System.out.println(key+" "+value); 
        }*/  
        //通过map.entrySet()方法  
        //循环map里面的每一对键值对,然后获取key和value  
        /*for(Entry<String, String> vo : map.entrySet()){ 
            vo.getKey(); 
            vo.getValue(); 
            System.out.println(vo.getKey()+"  "+vo.getValue()); 
        }*/