Use nonNegativeInteger : nonNegativeInteger « XML Schema « XML Tutorial

1. XML Tutorial
2. XML Schema
3. nonNegativeInteger

File: Schema.xml

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://www.java2s.com" xmlns="http://www.java2s.com"
  elementFormDefault="qualified">

  <xs:element name="population" type="xs:nonNegativeInteger" />

</xs:schema>


File: Data.xml
<?xml version="1.0"?>

<population xmlns="http://www.java2s.com">342</population>