Axis2 Web Service - Versioing

Question

I'm new to web services. I have developed a sample web service as shown below.

I'm trying to add a new field in the Data, say boolean sucess; . (Just to learn the backward compatibility)

When i add the new field, as i expected the service invocation fails from client stub.

How do i maintain different version of services. what all options i have?

I have gone through many articles on the net (unfortunately there are no examples. :(). And few options are

1) writing different operation in the class with the new output. This i understood.

2) Have versioning for the service. Like services/ version1 /SumAndMult, services/ version2 /SumAndMult

How do i achieve the second option? What is the idea behind this option? To maintain copy of the service classes?

If I have only one service Class on my sever, how can I expose multiple wsdls?

Also, what is the best way of maintaining backward compatibility?

public Data getSumAndMultData(int[] input){
    Data result = new Data();
    int sum = 0;
    int mult = 1;

    for(int i = 0; i < input.length; i++){
        sum += input[i];
        mult *= input[i];
    }
    result.setMult(mult);
    result.setSum(sum);
    return result;
}
class Data{
    int sum;
    int mult;
    public int getSum() {
        return sum;
    }
    public void setSum(int sum) {
        this.sum = sum;
    }

    public int getMult() {
        return mult;
    }
    public void setMult(int mult) {
        this.mult = mult;
    }
}

As

Answer 1

Case #2 really just means to add new web service with its own WSDL. You would probably start with the old WSDL, make whatever changes you needed, and then publish it under a different service name so that it's accessed through a different URL.

Using Axis2, you can package more than one service into the same AAR. Within services.xml, you will define a <servicegroup> with a <service> sections each service. All of the services will use the same classloader and have access to the same set of static variables.