写出一个缓存系统的伪代码001

/*** 写出一个缓存系统的伪代码*/
public class CacheDemo {private Map<String, Object> map = new HashMap<String, Object>();public static void main(String[] args) {// TODO Auto-generated method stub}    public synchronized Object getData(String key){ Object value = map.get(key);if (value == null){return "aaa";//实现QueryDB()
        }return value;}
}