Invoking a Java/AXIS Web Service from .NET: the ‘return null’ issue

Finally I solved this problem, a friend of mine helped me, apparently there were problems with the WSDL and the namespaces. C# generated the proxy wrong. Don't know if it's a c# problem or axis problem. But hope this answer helps anyone else.Take a look to all the namespaces on the methods of the WebService. C# Generated a method like this.

/// <remarks/>        [System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://www.openuri.org/InformacionPoliza", RequestNamespace = "http://www.openuri.org/", ResponseNamespace = "http://www.openuri.org/", Use = System.Web.Services.Description.SoapBindingUse.Literal, ParameterStyle = System.Web.Services.Protocols.SoapParameterStyle.Wrapped)]        [return: System.Xml.Serialization.XmlElementAttribute("Poliza")]        public Poliza InformacionPoliza(CriteriosPoliza CriteriosPoliza)        {            object[] results = this.Invoke("InformacionPoliza", new object[] {                    CriteriosPoliza});            return ((Poliza)(results[0]));        }

But in the WSDL had something like this..

<wsdl:definitions xmlns:apachesoap="http://xml.apache.org/xml-soap" xmlns:impl="http://www.openuri.org/" xmlns:intf="http://www.openuri.org/" xmlns:tns1="http://www.example.org/PolizasBanorteSchemaCriterios" **xmlns:tns2="http://www.example.org/PolizasBanorteSchema"** xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:wsdlsoap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.openuri.org/"><!--WSDL created by Apache Axis version: 1.4 Built on Apr 22, 2006 (06:55:48 PDT)--><wsdl:types><schema xmlns="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" targetNamespace="http://www.openuri.org/"><import namespace="http://www.example.org/PolizasBanorteSchema"/><import namespace="http://www.example.org/PolizasBanorteSchemaCriterios"/><element name="InformacionPoliza"><complexType><sequence><element name="CriteriosPoliza" type="tns1:CriteriosPoliza"/></sequence></complexType></element><element name="InformacionPolizaResponse"><complexType><sequence>**<element name="Poliza" type="tns2:Poliza"/>**</sequence></complexType></element></schema>

Look at the <element name="Poliza" type="tns2:Poliza"/> it refers to the tns2 namespaceand it says xmlns:tns2="http://www.example.org/PolizasBanorteSchema"

So the generated proxy by .NET was wrong it had to be like this

/// <remarks/>        [System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://www.openuri.org/InformacionPoliza", RequestNamespace = "http://www.openuri.org/", ResponseNamespace = "http://www.openuri.org/", Use = System.Web.Services.Description.SoapBindingUse.Literal, ParameterStyle = System.Web.Services.Protocols.SoapParameterStyle.Wrapped)]        [return: System.Xml.Serialization.XmlElementAttribute("Poliza", Namespace = "http://www.example.org/PolizasBanorteSchema")]        public Poliza InformacionPoliza(CriteriosPoliza CriteriosPoliza)        {            object[] results = this.Invoke("InformacionPoliza", new object[] {                    CriteriosPoliza});            return ((Poliza)(results[0]));        }

The namespace did the magic,

  [return: System.Xml.Serialization.XmlElementAttribute("Poliza", Namespace = "http://www.example.org/PolizasBanorteSchema")]

Changed that line of code and everything worked like a charmSo, be careful when using arrays and diferent namespaces in an axis service, you may have some problems generating a c# client.

This post was right :)