What does it imply to call a web service (SOAP over HTTP) stateless?

Question

I had a concept that HTTP is stateless, so SOAP over HTTP (for web services) is also stateless. I used to think that state meant “state of the object”. For an example, suppose I have a class called Employee and methods called setSalary and getSalary. If a caller of the web service calls setSalary and makes the salary 1000, then if getSalary is called, the caller should not necessarily get the value 10000. When I tested getsalary and got 1000 (i.e., the value assigned by setSalary), I was wondering how the state of the Employee object was maintained.

The Stack Overflow question Webservices are stateless? mentions tricks like cookies used to maintain state, but since I did not made any explicit effort to maintain state, how was the state of the Employee object maintained?

Please let me know if I have misunderstood the concept of state/stateless altogether.

Answer 1

Stateless means the state of the service don't persist between subsequent requests and response. whereas, in stateful the state is persisted between subsequent requests i.e. each request need to know and retain changes made in previous requests.

Banking application is an example of stateful application,where user first login then make transaction and logs out. If user tries to make the transaction after logout, he will not be able to do so.

Yes, http protocol is essentially a stateless protocol but to make it stateful we make use of HTTP cookies. So, is SOAP by default. But it can be make stateful likewise, depends upon framework you are using.

The case you provided, Are you trying to set and get values in subsequent requests or in same requests? Then only, i can comment on that.