Getting WebService return object in BPEL

Question

I have a simple WebService that returns a DTO object:
public MyDTO testDTO(String s1, String s2){
MyDTO myDTO = new MyDTO();
myDTO.setInput1(s1);
myDTO.setInput2(s2);
return myDTO;
public class MyDTO implements Serializable{
public MyDTO() {
private String input1;
private String input2;
//getters n setters are here
I deployed this as AXIS WebService in TomCat successfully.
<service name="elogService" provider="java:RPC" style="wrapped" use="literal">
<operation name="testDTO" qname="ns11:testDTO" returnQName="ns11:MyDTOReturn" returnType="ns51:com.MyDTO" soapAction="" xmlns:ns11="http://services.xyz.com" xmlns:ns51="http://dto.abc.com">
<parameter qname="ns11:s1" type="xsd:string" xmlns:xsd="http://www.w3.org/2001/XMLSchema"/>
<parameter qname="ns11:s2" type="xsd:string" xmlns:xsd="http://www.w3.org/2001/XMLSchema"/>
</operation>
<parameter name="allowedMethods" value="testDTO"/>
<parameter name="typeMappingVersion" value="1.2"/>
<parameter name="className" value="com.TestDTOWS"/>
<parameter name="wsdlServicePort" value="VisilogAddServicePort"/>
<parameter name="schemaQualified" value="http://services.xyz.com,http://dto.abc.com"/>
<parameter name="wsdlTargetNamespace" value="http://services.xyz.com"/>
<parameter name="wsdlServiceElement" value="elogService"/>
<typeMapping deserializer="org.apache.axis.encoding.ser.BeanDeserializerFactory" encodingStyle="" qname="ns31:MyDTO" serializer="org.apache.axis.encoding.ser.BeanSerializerFactory" type="java:com.MyDTO" xmlns:ns31="http://dto.abc.com"/>
</service>
In BPEL. I created a partnerLink and invoked it. In the BPEL Console, on giving inputs "a" and "b", i see the following message on invoke node:
Invoked 2-way operation "testDTO" on partner "DTOWS_PartnerLink".
- <messages>
- <Invoke_1_testDTO_InputVariable>
- <part xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="parameters">
- <testDTO xmlns="http://services.xyz.com">
<s1>a</s1>
<s2>b</s2>
</testDTO>
</part>
</Invoke_1_testDTO_InputVariable>
- <Invoke_1_testDTO_OutputVariable>
- <part xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="parameters">
- <testDTOResponse xmlns="http://services.xyz.com">
- <MyDTOReturn xsi:type="ns1:MyDTO" xmlns:ns1="http://dto.abc.com" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<input1>a</input1>
<input2>b</input2>
</MyDTOReturn>
</testDTOResponse>
</part>
</Invoke_1_testDTO_OutputVariable>
</messages
I assigned one of the WebService output variable to the result. At Assign node, i get the following message:
Error in evaluate <from> expression at line "98". The result is empty for the XPath expression : "/ns1:testDTOResponse/ns1:MyDTOReturn/ns2:input1".
oracle.xml.parser.v2.XMLElement@199822c
"{http://schemas.xmlsoap.org/ws/2003/03/business-process/}selectionFailure" has been thrown.
- <selectionFailure xmlns="http://schemas.xmlsoap.org/ws/2003/03/business-process/">
- <part name="summary">
<summary>
empty variable/expression result.
xpath variable/expression expression "/ns1:testDTOResponse/ns1:MyDTOReturn/ns2:input1" is empty at line 98, when attempting reading/copying it.
Please make sure the variable/expression result "/ns1:testDTOResponse/ns1:MyDTOReturn/ns2:input1" is not empty.
</summary>
</part>
</selectionFailure>
My input1 is not empty. I can see the result at the invoke node. It has "a" content in input1. What am i missing here. What are the places i need to check for.
Thanks....

Answer 1

I modified the WebService. Now WSDL file looks as follows:
<wsdl:types>
<schema elementFormDefault="qualified" targetNamespace="http://dto.com">
<element name="s1" type="xsd:string"/>
<element name="s2" type="xsd:string"/>
<complexType name="com.MyDTO">
<sequence>
<element name="input1" nillable="true" type="xsd:string"/>
<element name="input2" nillable="true" type="xsd:string"/>
</sequence>
</complexType>
<element name="testDTOReturn" type="impl:com.MyDTO"/>
</schema>
</wsdl:types>
However My error still persists:
Error in evaluate <from> expression at line "98". The result is empty for the XPath expression : "/ns3:testDTOReturn/ns3:input1".
<summary>
empty variable/expression result.
xpath variable/expression expression "/ns3:testDTOReturn/ns3:input1" is empty at line 98, when attempting reading/copying it.
Please make sure the variable/expression result "/ns3:testDTOReturn/ns3:input1" is not empty.
</summary>
At invoke node this is the message:
<Invoke_1_testDTO_OutputVariable>
- <part xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="testDTOReturn">
- <s1Return xsi:type="ns1:com.MyDTO" xmlns="http://dto.com" xmlns:ns1="http://dto.com" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<ns1:input1>1111</ns1:input1>