Keeping Service Object Method Running

Question

Does anyone have any suggestions how I can handle the followingsituation:
>
We want a service object to begin each morning and beavailable all day.
>
This service object contains a timer event that at specified timeswill
send events to certain users. Our approach this far has been for thefirst
user to sign on in the morning would start a task that would createthe
timer. Each subsequent user would first check if the timer is runningand
if it is, they would bypass this step. This works great until thefirst
user closes the application which in turn kills the task whichcontains the
timer.
How can we start a task that will not be killed when theparent is kille
d?
Any suggestions are greatly appreciated.
TIA
Tony
I'd suggest starting up the service independent of the clients by using
escript. The start task would be put into the INIT method of the
service object. You can put the escript commands in a batch job started
by a job scheduler. You can also shut down the service in the same
manner.
Bill

Answer 1

While I think I understand your thought process that led you to your design you have made an erroneous assumption when it comes to interfaces that has put you off the rails.
Casting to an interface does not magically mean that you can deserialize an object created with a non-existant class.
Which is what you are doing.
Let us say you have two classes...
public class ServisArayuzuServerImplementation implements ServisArayuzuand
public class ServisArayuzuClientImplementation implements ServisArayuzuThe problem is that when the server object is serialized in it's header it says it is a ServisArayuzuServerImplementation. Thus this class MUST exist on the client side if it is to be deserialized. And this MUST happen before any casting etc.
There are two possible solutions for the problem.
1) Use the same class on both sides.
2) Don't use ObjectInput and ObjectOutput streams but serialize the data yourself using DataInput and DataOutput streams. Then you can construct and deconstruct the objects as you need too. And they could be differen types if you wanted. This solution though is more complex so you'll have to decide for yourself.