自定义深拷贝

public CAggregate clone()
{
      CAggregate newObj = new CAggregate();
      //newObj.list = this.list;
      newObj.list = new ArrayList();
      for(int i = 0 ; i < this.list.length ; i++)
      {
          newObj.list[i] = this.list[i];
      }
      return newObj;
}