Checkbox values can not be unset

I may be asking the wrong questions here.

This is a jsp project that I am m开发者_运维技巧aking small change to. I added a new checkbox to the page. Saving the form with the checkbox checked seems to be working as expected; however, if the box is unchecked and the form is submitted for saving, it seems to be ignoring the checkbox -- it stays checked upon refresh.

I use firebug and find that the submitted form content indeed does not contain "mycheckbox=" pair.

The business object seems to be automatically constructed by Spring, and its values are automatically filled in, so I don't know where I can intercept the flow and consider the lack of "mycheckbox" as an uncheck.

Any pointers?

edit: i believe webflow is also used in this project.

edit2: I violated inter-galatic law to get it to work, by using a string in code and varchar(1) in the DB, with 'Y' to indicate true, and 'N' to indicate false.

You have two choices :

1: you use Spring tag :

<form:checkbox path="check_name" checked="true" />

2: you use html

<input type="checkbox" name="check_name" id="check_name" checked="true" />
<input type="hidden" name="_check_name" value="on" />

With the second choice, Spring will use the _check_name to set the value.