code: public static ObjectInfo getObjectInfo(Class c)
  	{
  		ObjectInfo info = cachedClassInfoMap.get(c);
  		if (info == null)
  		{
  			synchronized (c)
  			{
  
  				info = new ObjectInfo(c);
  				cachedClassInfoMap.put(c, info);
  			}
  		}
  		return info;
  	}
docs: 获取一个ObjectInfo
  @param c
  @return