This is due to the WSDLs Axis generates when using RPC or Doc/Wrapped
styles.
In the RPC case arrays are wrapped in XMLschema complexType while
in the Doc/Wrapped case they are used as simple repeated element in
the method response message declaration
RPC)
<wsdl:types>
...
<complexType name="ArrayOf_tns2_XYZ">
<sequence>
<element maxOccurs="unbounded" minOccurs="0" name="item"
type="tns2:XYZ"/>
</sequence>
</complexType>
</wsdl:types>
...
<wsdl:message name="getArrayResponse">
<wsdl:part name="getArrayReturn" type="impl:ArrayOf_tns2_XYZ"/>
</wsdl:message>
Wrapped)
<wsdl:types>
...
<element name="getArrayResponse">
<complexType>
<sequence>
<element maxOccurs="unbounded" name="getArrayReturn"
type="tns2:XYZ"/>
</sequence>
</complexType>
</element>
</wsdl:types>
...
<wsdl:message name="getArrayResponse">
<wsdl:part element="impl:getArrayResponse" name="parameters"/>
</wsdl:message>
*** Unzipping my comment
I've expaned a little bit more your example:
------ class MyWebService.java - XYZ..java
public class MyWebService{
public XYZ[] getArray(){
return new XYZ[0];
}
}
public class XYZ {
private String name;
private int value;
public XYZ(){
name="";
value=0;
}
public void setName(String name){ this.name=name; }
public void setValue(int value){ this.value=value;}
public String getName(){ return name; }
public int getValue(){ return value; }
}
------
I've then generated RPC/literal WSDL: java -cp $AXISCLASSPATH:.
org.apache.axis.wsdl.Java2WSDL -o MyWebService.wsdl -l
http://127.0.0.1:8080/MyWebService -n urn:MyWebService
-pexample=urn:MyWebService -y RPC -u LITERAL MyWebService
------- MyWebService.wsdl.RPC-literal
<?xml version="1.0" encoding="UTF-8"?>
<wsdl:definitions targetNamespace="urn:MyWebService"
xmlns:apachesoap="http://xml.apache.org/xml-soap";
xmlns:impl="urn:MyWebService"
xmlns:intf="urn:MyWebService" xmlns:tns2="http://DefaultNamespace";
xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"; xmlns:wsdlsoap="ht
tp://schemas.xmlsoap.org/wsdl/soap/"
xmlns:xsd="http://www.w3.org/2001/XMLSchema";>
<!--WSDL created by Apache Axis version: 1.3
Built on Oct 05, 2005 (05:23:37 EDT)-->
<wsdl:types>
<schema targetNamespace="http://DefaultNamespace";
xmlns="http://www.w3.org/2001/XMLSchema";>
<import namespace="urn:MyWebService"/>
<import namespace="http://schemas.xmlsoap.org/soap/encoding/"/>
<complexType name="XYZ">
<sequence>
<element name="name" nillable="true" type="xsd:string"/>
<element name="value" type="xsd:int"/>
</sequence>
</complexType>
</schema>
<schema targetNamespace="urn:MyWebService"
xmlns="http://www.w3.org/2001/XMLSchema";>
<import namespace="http://DefaultNamespace"/>
<import namespace="http://schemas.xmlsoap.org/soap/encoding/"/>
<complexType name="ArrayOf_tns2_XYZ">
<sequence>
<element maxOccurs="unbounded" minOccurs="0" name="item"
type="tns2:XYZ"/>
</sequence>
</complexType>
</schema>
</wsdl:types>
<wsdl:message name="getArrayRequest">
</wsdl:message>
<wsdl:message name="getArrayResponse">
<wsdl:part name="getArrayReturn" type="impl:ArrayOf_tns2_XYZ"/>
</wsdl:message>
<wsdl:portType name="MyWebService">
<wsdl:operation name="getArray">
<wsdl:input message="impl:getArrayRequest"
name="getArrayRequest"/>
<wsdl:output message="impl:getArrayResponse"
name="getArrayResponse"/>
</wsdl:operation>
</wsdl:portType>
<wsdl:binding name="MyWebServiceSoapBinding" type="impl:MyWebService">
<wsdlsoap:binding style="rpc"
transport="http://schemas.xmlsoap.org/soap/http"/>
<wsdl:operation name="getArray">
<wsdlsoap:operation soapAction=""/>
<wsdl:input name="getArrayRequest">
<wsdlsoap:body namespace="urn:MyWebService" use="literal"/>
</wsdl:input>
<wsdl:output name="getArrayResponse">
<wsdlsoap:body namespace="urn:MyWebService" use="literal"/>
</wsdl:output>
</wsdl:operation>
</wsdl:binding>
<wsdl:service name="MyWebServiceService">
<wsdl:port binding="impl:MyWebServiceSoapBinding"
name="MyWebService">
<wsdlsoap:address location="http://127.0.0.1:8080/MyWebService"/>
</wsdl:port>
</wsdl:service>
</wsdl:definitions>
-------
In this case note that Axis wraps the array of XYZ into an XML-schema
complexType and use it as the return type of the getArray() method.
<wsdl:message name="getArrayResponse">
<wsdl:part name="getArrayReturn" type="impl:ArrayOf_tns2_XYZ"/>
</wsdl:message>
where ArrayOf_tns2_XYZ is
<complexType name="ArrayOf_tns2_XYZ">
<sequence>
<element maxOccurs="unbounded" minOccurs="0" name="item"
type="tns2:XYZ"/>
</sequence>
</complexType>
In this case an array of 0 elements is correctly managed by Axis
Serializer/Deserializer.
****** And there was evening, and there was morning...
I've then generated WRAPPED WSDL:
java -cp $AXISCLASSPATH:. org.apache.axis.wsdl.Java2WSDL -o
MyWebService.wsdl -l http://127.0.0.1:8080/MyWebService -n
urn:MyWebService -pexample=urn:MyWebService -y WRAPPED MyWebService
------ MyWebService.wsdl.WRAPPED
<?xml version="1.0" encoding="UTF-8"?>
<wsdl:definitions targetNamespace="urn:MyWebService"
xmlns:apachesoap="http://xml.apache.org/xml-soap";
xmlns:impl="urn:MyWebService"
xmlns:intf="urn:MyWebService" xmlns:tns2="http://DefaultNamespace";
xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"; xmlns:wsdlsoap="ht
tp://schemas.xmlsoap.org/wsdl/soap/"
xmlns:xsd="http://www.w3.org/2001/XMLSchema";>
<!--WSDL created by Apache Axis version: 1.3
Built on Oct 05, 2005 (05:23:37 EDT)-->
<wsdl:types>
<schema elementFormDefault="qualified"
targetNamespace="urn:MyWebService" xmlns="http://www.w3.org/2001/XMLSchema";>
<import namespace="http://DefaultNamespace"/>
<element name="getArray">
<complexType/>
</element>
<element name="getArrayResponse">
<complexType>
<sequence>
<element maxOccurs="unbounded" name="getArrayReturn"
type="tns2:XYZ"/>
</sequence>
</complexType>
</element>
</schema>
<schema elementFormDefault="qualified"
targetNamespace="http://DefaultNamespace";
xmlns="http://www.w3.org/2001/XMLSchema";>
<complexType name="XYZ">
<sequence>
<element name="name" nillable="true" type="xsd:string"/>
<element name="value" type="xsd:int"/>
</sequence>
</complexType>
</schema>
</wsdl:types>
<wsdl:message name="getArrayRequest">
<wsdl:part element="impl:getArray" name="parameters"/>
</wsdl:message>
<wsdl:message name="getArrayResponse">
<wsdl:part element="impl:getArrayResponse" name="parameters"/>
</wsdl:message>
<wsdl:portType name="MyWebService">
<wsdl:operation name="getArray">
<wsdl:input message="impl:getArrayRequest"
name="getArrayRequest"/>
<wsdl:output message="impl:getArrayResponse"
name="getArrayResponse"/>
</wsdl:operation>
</wsdl:portType>
<wsdl:binding name="MyWebServiceSoapBinding" type="impl:MyWebService">
<wsdlsoap:binding style="document"
transport="http://schemas.xmlsoap.org/soap/http"/>
<wsdl:operation name="getArray">
<wsdlsoap:operation soapAction=""/>
<wsdl:input name="getArrayRequest">
<wsdlsoap:body use="literal"/>
</wsdl:input>
<wsdl:output name="getArrayResponse">
<wsdlsoap:body use="literal"/>
</wsdl:output>
</wsdl:operation>
</wsdl:binding>
<wsdl:service name="MyWebServiceService">
<wsdl:port binding="impl:MyWebServiceSoapBinding"
name="MyWebService">
<wsdlsoap:address location="http://127.0.0.1:8080/MyWebService"/>
</wsdl:port>
</wsdl:service>
</wsdl:definitions>
-------
As you can see in this case it doesn't wrap the Array in a complexType
as in the RPC literal case (as I'd expect...) but it
leaves it as a repeated element in the getArray response element:
<element name="getArrayResponse">
<complexType>
<sequence>
<element maxOccurs="unbounded" name="getArrayReturn"
type="tns2:XYZ"/>
</sequence>
</complexType>
</element>
In this case you get a NullPointerException if a 0 elements array is sent.
Note that this happens also if you modify line <element
maxOccurs="unbounded" name="getArrayReturn" type="tns2:XYZ"/> as
<element maxOccurs="unbounded" minOccurs="0" name="getArrayReturn"
type="tns2:XYZ"/>.
*** My poor solution
What I did in order to obtain a WRAPPED WSDL/SOAP solution working as I
would expect was to manually edit the (WRAPPED) WSDL file wrapping the
array in a complexType:
<element name="getArrayResponse">
<complexType>
<sequence>
<element name="getArrayReturn" type="tns2:ArrayOfXYZ"/>
</sequence>
</complexType>
</element>
...
<complexType name="ArrayOfXYZ">
<sequence>
<element maxOccurs="unbounded" minOccurs="0" name="item"
type="tns2:XYZ"/>
</sequence>
</complexType>
-
*** Concluding...
The same problem and solution would apply also to arrays passed as
arguments of methods.
Is it a bug ?
Is it an error to assume Axis should wrap arrays when used as
return/argument types in methods?
Is there a way to force Axis to wrap arrays anyway?
Personally I choose to work in RPC/literal mode in order to avoid the
burden of manually editing the WSDL doc for fufure evolution and
re-generations...
