Problem in invoking the web services

Question

Hi all,
I am new to java web services
i develoed a simple webservices here i am posting the code
i generated every thing using wstools of Jboss4.0.5AS
package com.javasrc.webservices.age;
import java.rmi.Remote;
import java.rmi.RemoteException;
public interface Age extends Remote
public String age( String name, Integer age ) throws RemoteException;
package com.javasrc.webservices.age;
public class Age_Imp
     public String age( String name, Integer age )
          return name + " is " + age + " years old!";
when i am invoking using the client progrmme i am getting nullpointer exception
ie.
java.lang.NullPointerException
     at org.apache.axis.client.Call.getTypeMapping(Call.java:2402)
     at org.apache.axis.client.Call.setReturnType(Call.java:1230)
     at org.apache.axis.client.Call.setOperation(Call.java:1412)
     at org.apache.axis.client.AxisClientProxy.invoke(AxisClientProxy.java:369)
     at $Proxy0.age(Unknown Source)
     at com.javasrc.webservices.age.AgeClient.main(AgeClient.java:35)
Exception in thread "main"
**this is my client programm**
package com.javasrc.webservices.age;
import javax.xml.rpc.Service;
import javax.xml.rpc.ServiceFactory;
import com.javasrc.webservices.age.Age;
import javax.xml.namespace.QName;
import java.net.URL;
public class AgeClient
public static void main( String[] args ) throws Exception {
if( args.length < 3 )
System.out.println( "Usage: AgeClient urlstr name age" );
System.exit( 0 );
String urlstr = args[ 0 ];
String argument = args[ 1 ];
String argument2 = args[ 2 ];
System.out.println( "Contacting webservice at " + urlstr );
URL url = new URL(urlstr);
QName qname = new QName("http://age.webservices.javasrc.com/",
"AgeService");
ServiceFactory factory = ServiceFactory.newInstance();
Service service = factory.createService( url, qname );
Age age = ( Age ) service.getPort( Age.class );
System.out.println( "age.age(" + argument + ", " + argument2 + ")" );
String result = age.age(argument,new Integer( argument2 ));//here i am getting error
System.out.println( "output:" + result );
pls help in resolving this

Answer 1

Assuming this is for Oracle BPM 11g.
I'm a novice at this and sure others will have infinitely better ideas (have I lowered your expectations enough?), but here are two thoughts. Both of these ideas assume that your child process was invoked by an Oracle BPM parent process.
When you expose a process as a web service and invoke it asynchronously from a parent process, there is a call back service available. I've yet to figure out exactly how to get it to work, but if you look at the "Start" event's property in the composite (it's the service) you will see the callback information in the bottom dropdown. I believe what this means is that from your child process, you can use a Service activity to invoke a service that invokes the callback service back to the parent process's Service activity.
My other idea (you're not going to like this one) would be to to invoke the subprocess using a Message Start Event activity instead of the Service activity you're currently using. If you go this route, then you could have your parent process kick off the child subprocess using a Message Start Event activity and then immediately after this have a Message Catch Event activity. The child process could have a Message Throw Event activity immediately after its Start Message Event activity that sends a notification to the parent process. The good part about this is that I've actually gotten this to work.
You can send argument information back to the parent process, but (sorry) I don't yet know how to capture the process id.
Wish I could be of more help and hope this helps a little.