Re: xs:nill

From: Peter Hendry <peter.hendry_at_capeclear.com>
Date: Mon, 25 Jun 2007 21:42:44 +1200

The behaviour is correct. To send null for the actual reference to an array the element would have to be omitted. Consider a 2 element array with both elements being nil <aliases xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nil="true"/> <aliases xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nil="true"/> So a one element array with a single null value would *have to* look like <aliases xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nil="true"/> An array which is a reference to null Aliases[] array = null; can only be serialized as omission. Serializing it as xsi:nil="true" is incorrect and I would suggest should error if attempted when minOccurs="1". Note that with this approach there is no way to differentiate between Aliases[] array = null; Aliases[] array = {}; Both would serialize by omission. The way around this confusion is to use wrapped arrays. I'm guessing JAX-WS probably has an option to generate wrapped arrays. My preference would be to generate these by default as they remove any confusion over what nil="true" means <sequence> <element name="aliases" nillable="true"> <complexType> <sequence> <element name="alias" type="tns:criteriaAlias" nillable="true" minOccurs="0" maxOccurs="unbounded"/> </sequence> </complexType> </element> <sequence> So Alias[] array = null; becomes <aliases xsi:nil="true"/> and Alias[] array = {}; becomes <aliases/> and Alias[] array = { null }; becomes <aliases> <alias xsi:nil="true"/> </aliases> So you can safely and unambiguously represent all 3 of Alias[] array = null; Alias[] array = {}; Alias[] array = { null }; Pete

Dima Gutzeit wrote:

BTW,

The schema that is generated by JAXWS contains "nillable='true'", os it is ok for the client to send it ,,,

<xs:complexType name="searchCriteria">
<xs:sequence>
<xs:element name="aliases" type="tns:criteriaAlias" nillable="true" minOccurs="0" maxOccurs="unbounded"></xs:element>
<xs:element name="criterions" type="tns:criterion" nillable="true" minOccurs="0" maxOccurs="unbounded"></xs:element>
<xs:element name="numberOrItemsPerRequest" type="xs:int"></xs:element>
<xs:element name="orders" type="tns:order" nillable="true" minOccurs="0" maxOccurs="unbounded"></xs:element>
<xs:element name="requestNumber" type="xs:int"></xs:element>
<xs:element name="requireTotalRequestsCount" type="xs:boolean"></xs:element>
<xs:element name="subCriterias" type="tns:subCriteria" nillable="true" minOccurs="0" maxOccurs="unbounded"></xs:element>
<xs:element name="totalRequestCount" type="xs:int"></xs:element>

</xs:sequence>
</xs:complexType>

----- Original Message -----

From: Dima Gutzeit

To: users@jax-ws.dev.java.net

Sent: Monday, June 25, 2007 9:49 AM

Subject: xs:nill

Hi,

I see strange deserializing behavior in JAXWS 2.1.2.

Whenever it gets :

<aliases xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nil="true"/>

It creates array with one null element. It is wrong :-(

Is there a way to configure this ?

Regards,

Dima Gutzeit.