Hi Duncan
Thanks for the analysis, comments inline
On 25/10/12 14:18, Duncan Keysell (dkeysell) wrote:
Hi,
In the application code for my REST service all the exceptions are wrapped in
WebApplicationException and then thrown. I have a test case to check this is
working and below is the resource called in that test case:
@GET
@Path("/plainBad")
public MgmtResponse throwPlainException() throws Exception {
throw new WebApplicationException(new Exception("Some lame message"));
}
I have an exception mapper (implementation of
ExceptionMapper<WebApplicationException>) that creates the Response. This
Response contains the message from the original exception as well as the exception
type, up until I have moved to use 2.7.0.
This is due to a change in the JAXRSUtils.convertFaultToResponse(T, Message)
message between 2.6.2 and 2.7.0.
Previously the method was (line 1217):
public static<T extends Throwable> Response convertFaultToResponse(T ex,
Message inMessage) {
ExceptionMapper<T> mapper =
ProviderFactory.getInstance(inMessage).createExceptionMapper(ex.getClass(),
inMessage);
if (mapper != null) {
try {
return mapper.toResponse(ex);
} catch (Exception mapperEx) {
mapperEx.printStackTrace();
return Response.serverError().build();
}
}
return null;
}
And now it is (line 1352):
@SuppressWarnings("unchecked")
public static<T extends Throwable> Response convertFaultToResponse(T ex,
Message inMessage) {
ProviderFactory factory = ProviderFactory.getInstance(inMessage);
ExceptionMapper<T> mapper = factory.createExceptionMapper(ex,
inMessage);
if (mapper != null) {
if (ex.getClass() == WebApplicationException.class
&& mapper.getClass() != WebApplicationExceptionMapper.class) {
WebApplicationException webEx = (WebApplicationException)ex;
Class<?> exceptionClass =
getWebApplicationExceptionClass(webEx.getResponse(),
WebApplicationException.class);
if (exceptionClass != WebApplicationException.class) {
try {
Constructor<?> ctr =
exceptionClass.getConstructor(Response.class);
ex = (T)ctr.newInstance(webEx.getResponse());
} catch (Exception ex2) {
ex2.printStackTrace();
return Response.serverError().build();
}
}
}
try {
return mapper.toResponse(ex);
} catch (Exception mapperEx) {
mapperEx.printStackTrace();
return Response.serverError().build();
} finally {
factory.clearExceptionMapperProxies();
}
}
return null;
}
So the problem is that the exception 'ex' and my 'mapper' pass the if statement
(line 1356):
if (ex.getClass() == WebApplicationException.class
&& mapper.getClass() != WebApplicationExceptionMapper.class)
And then the ex gets over written and I loose all the details that the original
WebApplicationException was holding. Shouldn't the if statement be changed not to
allow any mapping implementing ExceptionMapper<WebApplicationException>? Is
there some workaround for this?
I'm going to work on test case shortly. The actual change was needed to
get new JAX-RS 2.0 exceptions such as NotFoundException (alternative to
new WebApplicationException(404)), etc, captured by existing
ExceptionMapper<WebApplicationException> mappers if no a mapper like
ExceptionMapper<NotFoundException> exists, but a regression has been
introduced.
The possible workarounds: provide ExceptionMapper<ServerErrorException>
or extend CXF WebApplicationExceptionMapper. Another one is CXF specific
and it is to register a custom CXF invoker which will get a chance to
capture the original WebApplicationException, I guess it should be the
last resort option, I'll provide more info if doing other exception
mappers won't help
Thanks, Sergey
Thanks
Duncan
