my dog learned polymorphism*
The moose likes Other Open Source Projects and the fly likes Apache POI Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login

Win a copy of Murach's Java Servlets and JSP this week in the Servlets forum!
JavaRanch » Java Forums » Products » Other Open Source Projects
Bookmark "Apache POI" Watch "Apache POI" New topic

Apache POI

Johannes Uhlmann

Joined: May 25, 2011
Posts: 5


i got a question regarding to the class hierarchy of Cell and the possibility to implement Comparable.

There are HSSFCell implements Cell and XSSFCell implements Cell. I wanted the compareTo functionality for both, hence my idea was to design a class like abstract class MyCell implements Cell, Comparable<Cell>. So i could implement compareTo but omit the Cell functions. The problem is that MyCell is not a Cell. Available options: 1.) always cast if a Cell is needed 2.) extend HSSFCell as well as XSSFCell and implement Comparable for both. Are there more options?


edit: ;-)
Paul Clapham

Joined: Oct 14, 2005
Posts: 18541

Perhaps something like

Another option would be to forget about making a Cell comparable; you can compare a MyCell object to an XSSFCell object, because you wrote the code for MyCell, but you can't compare an XSSFCell object to a MyCell object because you didn't write the code for XSSFCell. A Comparator might be a better idea.
jQuery in Action, 2nd edition
subject: Apache POI
Similar Threads
Sorting arrays
How to fix blue triangle in top left corner of cell in excel while creating using apache poi 3.6
Using generics and the Comparable interface to implement a node
Generics .. contravariance question on Collections.sort static method
Collections.sort method in java