Hi Kumar,
a workflow (i.e., process instance) has always a state. I assume that you want to have a stateless service task in your process, right?
For each service task, you have to specify the calling Java code, for example you can specify the Java delegate via class name or expression which can invoke a bean via CDI, Spring, etc. If you use a class name then a new instance of the Java Delegate is created each time the process arrives the service task. Otherwise, you have to deal with the instantiation, e.g., by defining the Spring bean. So in the end, it’s up to you how you build your services.
Does this help you?
Best regards,
Philipp