1.验证字符串长度在5-10个字符之间，并使用trim去首尾空格后校验
<field name="username"> <field-validator type="stringLength"> <param name="trim">true</param> <param name="minLength">5</param> <param name="maxLength">10</param> </field-validator> </field>
2.防止日期早于1970年
<field name="birthday"> <field-validator type="date"> <param name="min">01/01/1970</param> </field-validator> </field>3.校验int范围，并把验证范围传递到jsp显示
<field name="age"> <field-validator type="int"> <param name="min">0</param> <param name="max">10</param> <message>count must be between ${min} and ${max} current value is ${age} </field-validator> </field>