I have recently complete interoperable testing between .NET Web Services and a Java client using 2 different frameworks ( Axis / XFire ).  I am blogging my results in order to help myself remember the next time I have to do this as well as save others time in tracking down similar issues.

Both Axis and XFire are experiencing different flavors of the same issue, Inheritance.  Both frameworks seem to be addressing the base type instead of the type of the object instantiated.

The next 7 blogs will contain the source code and the tests to perform in order to experience the issues first hand.

• The .NET Web Service    ( Part 1 and 2 )
• Client code using Axis  ( Part 1 and 2 )
• Client code using XFire ( Part 1 and 2 )
• Tests and results

Here is the source code for the .NET Web Service as described in the previous blog. 
Save the following code into a file named SimpleAsmxService.asmx and place it in C:\Inetpub\wwwroot for IIS to use.




<%@WebService Language="C#" Class="MyService.Simple.SimpleAsmxService" %> 

  
using System.Web.Services; 
using System.Collections.Generic; 
using System.Xml.Serialization; 
        
namespace MyService.Simple 
{ 
    [WebService( Namespace = "urn:emp:service" )] 
    public class SimpleAsmxService : WebService 
    { 
        [WebMethod] 
        public Person GetPerson( Person person ) 
        { 
            Person newPerson = new Person(); 
        
            CreatePerson( person, newPerson ); 
        
            return ( newPerson ); 
        } 
        
        [WebMethod] 
        public List<Address> GetAddressList() 
        { 
            List<Address> addressList = new List<Address>(); 
        
            HomeAddress home = new HomeAddress(); 
            home.HouseNumber = "211 Pine Street"; 
        
            addressList.Add( home ); 
        
            return ( addressList ); 
        } 
        
        [WebMethod] 
        public List<HomeAddress> GetHomeAddress() 
        { 
            List<HomeAddress> addressList = new List<HomeAddress>(); 
        
            WorkAddress work = new WorkAddress(); 
            work.HouseNumber = "234 State Avenue"; 
            work.PhoneNumber = "555-1212"; 
        
            addressList.Add( work ); 
        
            return ( addressList ); 
        } 
        
        //[WebMethod] 
        //public List<WorkAddress> GetMatchingTypes() 
        //{ 
        //    List<WorkAddress> addressList = new List<WorkAddress>(); 
        
        //    WorkAddress work = new WorkAddress(); 
        //    work.HouseNumber = "234 State Avenue"; 
        //    work.PhoneNumber = "555-1212"; 
        
        //    addressList.Add( work ); 
        
        //    return ( addressList ); 
        //} 
 

        /// <summary> 
        /// 
        /// </summary> 
        /// <param name="oldPerson"></param> 
        /// <param name="newPerson"></param> 
        private void CreatePerson( Person oldPerson, Person newPerson ) 
        { 
            Address address; 
        
            if ( oldPerson.Address is WorkAddress ) 
                address = new WorkAddress(); 
            else 
                address = new HomeAddress(); 
        
            newPerson.Name = oldPerson.Name; 
            newPerson.Address = address; 
        
            if ( oldPerson.Address != null ) 
            { 
                if ( oldPerson.Address is HomeAddress ) 
                { 
                    ( newPerson.Address as HomeAddress ).HouseNumber = 
                        ( oldPerson.Address as HomeAddress ).HouseNumber; 
        
                    if ( oldPerson.Address is WorkAddress ) 
                    { 
                        ( newPerson.Address as WorkAddress ).PhoneNumber = 
                            ( oldPerson.Address as WorkAddress ).PhoneNumber; 
                    } 
                } 
                else 
                { 
                    ( newPerson.Address as HomeAddress ).HouseNumber = 
                        "Service Receive object type of: " + oldPerson.Address.GetType().Name; 
                } 
            } 
            else 
            { 
                ( newPerson.Address as HomeAddress ).HouseNumber = "987654 ELM STREET"; 
            } 
        } 
    } 
        
    /// <summary> 
    /// 
    /// </summary> 
    [XmlRoot( Namespace = "urn:emp:data" )] 
    public class Person 
    { 
        public string Name; 
        public Address Address; 
    } 
        
    /// <summary> 
    /// 
    /// </summary> 
    [XmlRoot( Namespace = "urn:emp:data" )] 
    [XmlInclude( typeof( HomeAddress ) )] 
    [XmlInclude( typeof( WorkAddress ) )] 
    public abstract class Address 
    { 
    } 
        
    /// <summary> 
    /// 
    /// </summary> 
    [XmlRoot( Namespace = "urn:emp:data" )] 
    [XmlInclude( typeof( WorkAddress ) )] 
    public class HomeAddress : Address 
    { 
        public string HouseNumber; 
    } 
        
    /// <summary> 
    /// 
    /// </summary> 
    [XmlRoot( Namespace = "urn:emp:data" )] 
    public class WorkAddress : HomeAddress 
    { 
        public string PhoneNumber; 
    } 
}

Here is the source code for the Java client using Axis.





/** 
 * 
 */ 
import service.emp.*; 
import data.emp.*; 
  
/** 
 * @author 
 * 
 */ 
public class SimpleAsmxAxisClient 
{ 
  
    /** 
     * @param args 
     */ 
    public static void main(String[] args) 
    { 
        GetPerson(); 
        GetAddress(); 
        GetWorkAddress(); 
    } 
    
    /** 
     * 
     */ 
    public static void GetPerson() 
    { 
        Person person; 
        Person newPerson; 
  
        try 
        { 
            // Create Proxy Class 
            SimpleAsmxServiceSoapProxy service = new SimpleAsmxServiceSoapProxy(); 
            
            // Create Person 
            person = new Person(); 
            person.setName( "Bob the Builder" ); 
  
            // 
            // DO NOT SEND THE ADDRESS 
            // 
            System.out.println( "\nDo NOT send Address to Service..." ); 
            newPerson = service.getPerson( person ); 
            Print( newPerson ); 
            
            // 
            // SEND THE ADDRESS 
            // 
            System.out.println( "\nSend Address to Service..." ); 
            HomeAddress homeAddress = new HomeAddress(); 
            homeAddress.setHouseNumber("456 Long and Winding Road "); 
            person.setAddress(homeAddress); 
            
            newPerson = service.getPerson( person ); 
            Print( newPerson ); 
        } 
        catch ( Exception ex ) 
        { 
            System.err.println(ex); 
        } 
    }

    /** 
     * @param newPerson 
     */ 
    public static void Print( Person newPerson ) 
    { 
        Object o; 
        
        if ( newPerson != null ) 
        { 
            System.out.println( "    Name: " + newPerson.getName() ); 
            
            o = newPerson.getAddress(); 
            if ( o != null) 
            { 
                System.out.println( "    Addr: " + ( (HomeAddress)newPerson.getAddress() ).getHouseNumber() ); 
            } 
            else 
            { 
                System.out.println( "    Addr: is null"  ); 
            } 
        } 
    } 
    
    /** 
     * 
     */ 
    public static void GetAddress() 
    { 
        try 
        { 
            Address[] listOfAddress; 
            
            // Create Proxy Class 
            SimpleAsmxServiceSoapProxy service = new SimpleAsmxServiceSoapProxy(); 
            listOfAddress = service.getAddressList(); 
            
            System.out.println( "\nStarting GetAddress()..." ); 
            Print( listOfAddress ); 
        } 
        catch ( Exception ex ) 
        { 
            System.err.println(ex); 
        }    
    } 
    
    /** 
     * 
     */ 
    public static void GetWorkAddress() 
    { 
        try 
        { 
            HomeAddress[] listOfAddress; 
            
            // Create Proxy Class 
            SimpleAsmxServiceSoapProxy service = new SimpleAsmxServiceSoapProxy(); 
            listOfAddress = service.getHomeAddress(); 
            
            System.out.println( "\nStarting GetWorkAddress()..." ); 
            Print( listOfAddress ); 
        } 
        catch ( Exception ex ) 
        { 
            System.err.println(ex); 
        }    
    } 
  
    /** 
     * @param newPerson 
     */ 
    public static void Print( Address[] listOfAddress ) 
    { 
        if (( listOfAddress != null ) && ( listOfAddress.length > 0)) 
        { 
            for ( int index = 0; index < listOfAddress.length; index++) 
            { 
                System.out.println( "    House Number: " + 
                    ((HomeAddress)listOfAddress[index]).getHouseNumber() ); 
                
                if ( listOfAddress[index] instanceof WorkAddress ) 
                { 
                    System.out.println( "    Phone Number: " + 
                        ((WorkAddress)listOfAddress[index]).getPhoneNumber() ); 
                } 
            } 
        } 
    } 
} 

Here is the source code for the Java client using XFire.





/** 
 * 
 */ 
import java.util.List; 
import emp.service.*; 
import emp.data.*; 
  
/** 
 * @author delliott 
 * 
 */ 
public class SimpleAsmxXFireClient 
{ 
  
    /** 
     * @param args 
     */ 
    public static void main(String[] args) 
    { 
        GetPerson(); 
        GetAddress(); 
        GetWorkAddress(); 
    } 
    
    /** 
     * 
     */ 
    public static void GetPerson() 
    { 
        Person person; 
        Person newPerson; 
  
        try 
        { 
            // Create Proxy Class 
            SimpleAsmxServiceClient service = new SimpleAsmxServiceClient(); 
            
            // Create Person 
            person = new Person(); 
            person.setName( "Bob the Builder" ); 
  
            // 
            // DO NOT SEND THE ADDRESS 
            // 
            System.out.println( "\nDo NOT send Address to Service..." ); 
            newPerson = service.getSimpleAsmxServiceSoap().getPerson( person ); 
            Print( newPerson ); 
            
            // 
            // SEND THE ADDRESS 
            // 
            System.out.println( "\nSend Address to Service..." ); 
            HomeAddress homeAddress = new HomeAddress(); 
            homeAddress.setHouseNumber("456 Long and Winding Road "); 
            person.setAddress(homeAddress); 
            
            newPerson = service.getSimpleAsmxServiceSoap().getPerson( person ); 
            Print( newPerson ); 
        } 
        catch ( Exception ex ) 
        { 
            System.err.println(ex); 
        } 
    } 


  
    /** 
     * @param newPerson 
     */ 
    public static void Print( Person newPerson ) 
    { 
        Object o; 
        
        if ( newPerson != null ) 
        { 
            System.out.println( "    Name: " + newPerson.getName() ); 
            
            o = newPerson.getAddress(); 
            if ( o != null) 
            { 
                System.out.println( "    Addr: " + ( (HomeAddress)newPerson.getAddress() ).getHouseNumber() ); 
            } 
            else 
            { 
                System.out.println( "    Addr: is null"  ); 
            } 
        } 
    }

   
    /** 
     * 
     */ 
    public static void GetAddress() 
    { 
        try 
        { 
            ArrayOfAddress listOfAddress; 
            
            // Create Proxy Class 
            SimpleAsmxServiceClient service = new SimpleAsmxServiceClient(); 
            listOfAddress = service.getSimpleAsmxServiceSoap().getAddressList(); 
            
            System.out.println( "\nStarting GetAddress()..." ); 
            Print( listOfAddress ); 
        } 
        catch ( Exception ex ) 
        { 
            System.err.println(ex); 
        }    
    } 
    
  
    /** 
     * @param listOfAddress 
     */ 
    public static void Print( ArrayOfAddress listOfAddress ) 
    { 
        if ( listOfAddress != null ) 
        { 
            List<Address> addressList = listOfAddress.getAddress(); 
            
            for ( int index = 0; index < addressList.size(); index++) 
            { 
                System.out.println( "    House Number: " + 
                    ((HomeAddress)addressList.get( index ) ).getHouseNumber() ); 
            } 
        } 
    } 
  
    
    /** 
     * 
     */ 
    public static void GetWorkAddress() 
    { 
        try 
        { 
            ArrayOfHomeAddress listOfAddress; 
            
            // Create Proxy Class 
            SimpleAsmxServiceClient service = new SimpleAsmxServiceClient(); 
            listOfAddress = service.getSimpleAsmxServiceSoap().getHomeAddress(); 
            
            System.out.println( "\nStarting GetWorkAddress()..." ); 
            Print( listOfAddress ); 
        } 
        catch ( Exception ex ) 
        { 
            System.err.println(ex); 
        }    
    } 
    
    /** 
     * @param listOfAddress 
     */ 
    public static void Print( ArrayOfHomeAddress listOfAddress ) 
    { 
        HomeAddress address; 
        
        if ( listOfAddress != null ) 
        { 
            List<HomeAddress> addressList = listOfAddress.getHomeAddress(); 
            
            for ( int index = 0; index < addressList.size(); index++) 
            { 
                address = addressList.get( index ); 
                
                    System.out.println( "    House Number: " + 
                        ((WorkAddress)address).getHouseNumber() ); 
                    System.out.println( "    Phone Number: " + 
                        ((WorkAddress)address).getPhoneNumber() ); 
            } 
        } 
    }    
}

SimpleAsmxClient
  
  
Test 1:  
Step 1: Run Java Client 
  
Results: 3 of the 4 Prints are successful 
  
Send Address to Service... 
  
System.Web.Services.Protocols.SoapException: Server was unable to read request. ---> 
System.InvalidOperationException: There is an error in XML document (1, 337). ---> 
System.InvalidOperationException: 
The specified type is abstract: name='Address', namespace='urn:emp:data', at 
<Address xmlns='urn:emp:data'>. 
  
Test 2: 
Step 1: Modify Person.java 
Change all instance of 
data.emp.Address 
To 
data.emp.HomeAddress 
  
Step 2: Run Java Client 
  
Results: 4 of the 4 Prints are successful 
  
  
  
  

SimpleAsmxXFireClient
  
  
Test 1:  
Step 1: Run Java Client 
  
Results: 3 of the 4 Prints are successful 
   
            Starting GetWorkAddress()... 
            java.lang.ClassCastException: emp.data.HomeAddress 
  
  
Test 2: 
   
Step 1: Modify SimpleAsmxService.asmx 
Change 
[WebMethod] 
public List<HomeAddress> GetHomeAddress() 
To 
// [WebMethod] 
public List<HomeAddress> GetHomeAddress() 
  
Step 2: Rebuild Java Proxy Classes 
  
Step 3: Comment out code in Java Client 
GetWorkAddress(); 
  
public static void GetWorkAddress() 
{ 
... 
} 
  
public static void Print( ArrayOfHomeAddress listOfAddress ) 
{ 
... 
} 
  
Step 4: Run Java Client 
  
Results: 2 of the 3 Prints are successful 
public static void GetAddress() fails to retrieve data 
  
org.codehaus.xfire.XFireRuntimeException: Could not invoke service.. 
Nested exception is org.codehaus.xfire.fault.XFireFault: Could not unmarshall type. 
  
Test 3: 
Step 1: Restore original files 
·         SimpleAsmxService.asmx 
·         SimpleAsmxXFireClient.java 
  
Step 2: Modify SimpleAsmxService.asmx 
Uncomment the following method 
  
[WebMethod] 
public List<WorkAddress> GetMatchingTypes() 
{ 
... 
} 
   
  
Step 3: Rebuild Java Proxy Classes 
  
Step 4: Run Java Client 
  
Results: 4 of the 4 Prints are successful