Question

I am validating the decimal places with precision (5,2) which can have negative numbers using regular expresion in struts.
When I try to run this ^[-+]?[0-9]{1,3}+(\.[0-9]{1,2})$
in java it is working fine. But, the same expression in struts is throwing below error.

org.apache.struts.validator.FieldChecks processFailure mask validation failed for property inputCost: org.apache.oro.text.MalformedCachePatternException: Invalid expression: ^[-+]?[0-9]{1,3}+(\.[0-9]{1,2})$
Nested repetitions *?+ in expression

Here is the code snippet of validation.xml.

        <field property="inputCost" depends="double,mask">
            <arg position="0"  key="label.inputCost"/>
            <msg name="mask" key="label.inputCost.mask"/>
            <var>
                <var-name>mask</var-name>
                <var-value>^[-+]?[0-9]{1,3}+(\.[0-9]{1,2})$</var-value>
            </var>
        </field>

Any inputs are greatly appreciated.

Answer 1

Your regex is technically incorrect. You can’t have a + after a {,} qualifier, it’s like saying .*+ or .?* (the + is a special metacharacter in regex meaning “one or more”, just like * means “zero or more”).

Try

^[-+]?[0-9]{1,3}(\.[0-9]{1,2})$

Notice the {1,3}+ is just a {1,3}.