How to get the values ​​transmitted by multiple Checkbox on the page on the page

The multi-selection box is named, and the user does not select the multi-select box at all, it cannot be obtained by request.getParameterValues ​​(String parametervalues ​​(String parameterValues), and its return value is an array of users selected Checkbox,

No line JavaScript code

On the servlet

String [] GroupIDS = Request.getParameterValues ​​("groups");

Checkbox, so, radio, selectbox is no exception