关于struts2的checkboxlist、select等标签发生could not be resolved as a collection/array/map/enumeration/iterator
今天研究struts2的标签功能,在用checkboxlist的时候,代码如下出现了如下异常:org.apache.jasper.JasperException: tag 'checkboxlist', field 'list', name 'selectRoleId': The requested list key 'roles' could not be resolved as a colle