JAX-WS and RuntimeException in service implementation

[Sebastian Millies]

Hello,

I am confused with regard to the treatment of runtime
exceptions in a webservice call. Can anyone give an explanation
(or point me to one) that is clearer and more complete than the
JAX-WS spec itself?

The scenario:
Supppose I call a webservice in Java over a JAX-WS 2.1
compliant SOAP implementation and the service implementation
throws a java.lang.RuntimeException. What happens on the
service and the client side?

What the spec has to say:
The JAX-WS spec says in section 3.7 :
java.lang.RuntimeException and java.rmi.RemoteException and their
subclasses MUST NOT be treated as service specific exceptions and
MUST NOT be mapped to WSDL.

Sections 5.1.1.1 and 6.4.1 about protocol specific exceptions seem
not to apply, because a runtime exception that occurs e. g. because
of an SQL Error on the server side certainly would not qualify as
a subclass for the SOAP protocol.

My questions:
Thus, on the client side I expect to see nothing in the returned SOAP
message. I also do not expect a WebServiceException, because these
occur if there is any error prior to invocation of the operation.
Am I right?

Given that a runtime exception may always occur on the server
(external resource not availabe etc.) am I thus forced to wrap any
runtime exception in some service exception in my service
implementation?

Comment:
It would be tedious if I were right. Especially if I do not know at
coding time whether my service will be called using a web service
or directly in the same JVM (this may vary with the deployment
configuration, just think of SCA components), I'd be effectively
barred from using unchecked exceptions.


-- Sebastian

 

[Daniel Pitts]

Hello,

I am confused with regard to the treatment of runtime
exceptions in a webservice call. Can anyone give an explanation
(or point me to one) that is clearer and more complete than the
JAX-WS spec itself?

The scenario:
Supppose I call a webservice in Java over a JAX-WS 2.1
compliant SOAP implementation and the service implementation
throws a java.lang.RuntimeException. What happens on the
service and the client side?

What the spec has to say:
The JAX-WS spec says in section 3.7 :
java.lang.RuntimeException and java.rmi.RemoteException and their
subclasses MUST NOT be treated as service specific exceptions and
MUST NOT be mapped to WSDL.

Sections 5.1.1.1 and 6.4.1 about protocol specific exceptions seem
not to apply, because a runtime exception that occurs e. g. because
of an SQL Error on the server side certainly would not qualify as
a subclass for the SOAP protocol.

My questions:
Thus, on the client side I expect to see nothing in the returned SOAP
message. I also do not expect a WebServiceException, because these
occur if there is any error prior to invocation of the operation.
Am I right?

Given that a runtime exception may always occur on the server
(external resource not availabe etc.) am I thus forced to wrap any
runtime exception in some service exception in my service
implementation?

External resource not available should be a checked exception, not a
runtime exception.

Comment:
It would be tedious if I were right. Especially if I do not know at
coding time whether my service will be called using a web service
or directly in the same JVM (this may vary with the deployment
configuration, just think of SCA components), I'd be effectively
barred from using unchecked exceptions.

You're service should throw service specific exceptions. This is good
design, regardless of whether it is a web-service or not.

As for the SOAP protocol, I'm not too familiar with it, so I can't
answer your specific question above.

 

[Tom Anderson]

I am confused with regard to the treatment of runtime
exceptions in a webservice call. Can anyone give an explanation
(or point me to one) that is clearer and more complete than the
JAX-WS spec itself?

The scenario:
Supppose I call a webservice in Java over a JAX-WS 2.1
compliant SOAP implementation and the service implementation
throws a java.lang.RuntimeException. What happens on the
service and the client side?

What the spec has to say:
The JAX-WS spec says in section 3.7 :
java.lang.RuntimeException and java.rmi.RemoteException and their
subclasses MUST NOT be treated as service specific exceptions and
MUST NOT be mapped to WSDL.

Sections 5.1.1.1 and 6.4.1 about protocol specific exceptions seem
not to apply, because a runtime exception that occurs e. g. because
of an SQL Error on the server side certainly would not qualify as
a subclass for the SOAP protocol.

My questions:
Thus, on the client side I expect to see nothing in the returned SOAP
message. I also do not expect a WebServiceException, because these
occur if there is any error prior to invocation of the operation.
Am I right?

Given that a runtime exception may always occur on the server
(external resource not availabe etc.) am I thus forced to wrap any
runtime exception in some service exception in my service
implementation?

My guess would be that the SOAP implementation will catch a runtime
exception and return a fault, with a faultcode of Server. Chances are that
the client SOAP stack will turn this into an exception again - in java, a
SOAPFaultException.

I don't have the JAX-WS to hand, so i can't actually cite any evidence for
this, though.

tom