Solution to “f:validateRequired doesn’t work”

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I found this problem on my JSF application running on Tomcat: the  didn’t work: When I let the input field empty and submit, no validation message shown and the field value became zero automatically.


1) Tomcat convert null value to Zero automatically, so add this JVM option to -Dorg.apache.el.parser.COERCE_TO_ZERO=false

2) JSF doesn’t validate empty field by default! Set this context parameter, javax.faces.VALIDATE_EMPTY_FIELDS, to true in web.xml


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