Question

I am running a service A which has a class X. I am going to deploy another service B on same machine which is using this class X. How can I make sure that the same instance of service A is reused instead of another.

PS:Service written in JAVA.

Adding: Both these services are Axis2 services. Service B is hot-deployed. Service B used class Y which is extension of class X.

Answer 1

Could we try to distinguish classes, objects and services.

You have something like this?

@javax.jws.WebService
public class ServiceAAA{

    public String echo(String arg) {
        // some really nice code here     
    }

}

and you want to add

@javax.jws.WebService
public class ServiceBBB{
    public String superEcho(String arg) {
        // even more code here
        // which needs to reuse the code from A's echo()     
    }   
}

So clearly we don’t want to cut and paste between the two implementations. How do we reuse?

Alternative 1:

Directly call A from B. You are asking how to do that. It could be done. You would just code a JAX-WS client call in your implmentation. However I stringly recommend against this. A service call is likely to be more expensive than a simple Java call.

Only do this if y6ou don’t have the option of deploying the two service classes together.

Alternative 2:

Refactor the implementation. Just move the code into a worker class.

@javax.jws.WebService
public class ServiceAAA{

    MyWorker worker = new Worker();
    public String echo(String arg) {
        return worker.doSomething(arg) ;      
    }

}

@javax.jws.WebService
public class ServiceBBB{

    MyWorker worker = new Worker();
    public String superEcho(String arg) {
        worker.doSomething(arg) ;  
        // and some morestuff             
    }    
}