Check if a string contains number or is numeric - Thymeleaf

Question

Is there a way to check if string is numeric. {#strings.isNumeric(dataField)} doesn't work.

How can I check if string contains numbers (specific number of digits as well) - is there a RegEx that can be used, or an inbuilt function that can be called?

Want to avoid this below:

{#string.contains('1') or #string.contains('2')}

Bohemian · Accepted Answer · 2016-02-03T20:44:00.367

2

Try matches():

{#dataField.matches('[0-9]{3,8}')}

This matches a string that is from 3 to 8 digits long (inclusive). You can change those values to whatever works for you.

You can also use open-ended length ranges: [0-9]{3,} means "at least 3 digits"

edited Feb 03 '16 at 20:44

answered Jan 28 '16 at 22:55

Bohemian

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For some reason this is not working testStringResult = ${#strings.matches(testString, '[0-9]')} – Loser Coder Feb 01 '16 at 22:32
Error: org.springframework.expression.spel.SpelEvaluationException: EL1004E:(pos 9): Method call: Method matches(java.lang.String, java.lang.String) cannot be found on org.thymeleaf.expression.Strings type at org.springframework.expression.spel.ast.MethodReference.findAccessorForMethod(MethodReference.java:273) – Loser Coder Feb 02 '16 at 06:24
@loser I'm not familiar with thymeleaf, but try my edited code – Bohemian Feb 03 '16 at 20:44

score 1 · Answer 2 · answered Feb 17 '17 at 10:24

If you have in your path the library org.apache.commons.lang3 you could use it as next

${T(org.apache.commons.lang3.StringUtils).isNumeric(dataField)}

So in case you want to use an if block it would be:

<th:block th:if="${T(org.apache.commons.lang3.StringUtils).isNumeric(dataField)}">
   <p>Is numeric!</p>
</th:block/>

Otherwise, if you don't have org.apache.commons.lang3 in your classpath you could implement your own method which checks if it is numeric and then use it. So you could create a class like next:

package your.package;

public class Utils {
     public static boolean isNumeric(String data){
           //impl
           return true;
     }
}

And then use it the next expression:

${T(your.package.Utils).isNumeric(dataField)}

Check if a string contains number or is numeric - Thymeleaf

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