前面讲述的数据有效性验证有不妥的地方，现在做下面的修正：
PriceIncreaseFormAction-validation.xml修正如下：
<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0//EN" "http://www.opensymphony.com/xwork/xwork-validator-1.0.dtd">
<validators>
<field name="priceIncrease.percentage">
<field-validator type="required" short-circuit="true">
<message key="error.not-specified">Value required.</message>
</field-validator>
<!--
<field-validator type="fieldexpression" short-circuit="true">
<param name="expression">priceIncrease.percentage > 0</param>
<message key="error.too-low">Value too low.</message>
</field-validator>
-->
<field-validator type="int" short-circuit="true">
<param name="min">1</param>
<message key="error.too-low">Value too low.</message>
</field-validator>
<field-validator type="int" short-circuit="true">
<param name="max">50</param>
<message key="error.too-high">Value too high.</message>
</field-validator>
</field>
</validators>
ActionSupport.properties修正如下：
#error.too-low=You have to specify a percentage higher than ${expression}%!
error.too-low=You have to specify a percentage higher than ${min-1}%!
