How to enable schema validation so that JAXB rejects empty element?

Question

I have encountered a wiered JAXB parsing issue. I am using JAXB RI 2.x. I have enabled the schema validation using "unmarshaller.setSchema(schema)". However, if the XML contains an empty element, JAXB does not throw any validation error. So the clients are happily passing empty string values!!

Here is how the element is declared in the schema:

(Please see my comments below)

Here is how it appears in the XML instance:

(Please see my comments below)

Even though it is a required field, it is successfully validated by JAXB. How do I enable the rejection of such empty elements?

Thanks

Answer 1

You need to declare a new simple type in your XML schema that is a restriction of xsd:string that includes the minLength facet.

<xs:element name="ChargeCode" type="stringMinSize1"/>
<xs:simpleType name="stringMinSize1">
    <xs:restriction base="xs:string">
        <xs:minLength value="1"/>
    </xs:restriction>
</xs:simpleType>

You can also use other facets such as pattern to further control what the string content looks like. A typical example is that of a Canadian postal code which alternates between letters:

<xs:element name="PostalCode" type="postalCode"/>
<xs:simpleType name="postalCode">
    <xs:restriction base="xs:string">
        <xs:pattern value="[A-Z]{1}[0-9]{1}[A-Z]{1} [0-9]{1}[A-Z]{1}[0-9]{1}"/>
    </xs:restriction>
</xs:simpleType>

The question below deals with a pattern to require strings with content.

• XML schema restriction pattern for not allowing empty strings

For an example see:

• http://bdoughan.blogspot.com/2010/12/jaxb-and-marshalunmarshal-schema.html

Answer 2

you can use minOccurs parameter