Hi
In Camel 1.4 we are improving the validation when Camel creates endpoints
(CAMEL-433) regarding the given URI string.
Use-case
========
As of now Camel will throw a ResolveEndpointFailedException if the validation
failed with a message what is the problem.
Camel will now validate out-of-the-box:
1) Simple URI syntax
2) No more lost parameters
Ad 1)
The simple syntax validation is eg. If the end-user has forgotten that the
parameters separator is a ? marker and to use & for further parameters.
So this invalid URI: timer://foo&fixedRate=true&delay=0&period=500
Will fail since there are no ? marker.
Failed to resolve endpoint: timer://foo&fixedRate=true&delay=0&period=500 due
to: org.apache.camel.ResolveEndpointFailedException: Failed to resolve
endpoint: timer://foo&fixedRate=true&delay=0&period=500 due to: Invalid uri
syntax: no ? marker however the uri has & parameter separators. Check the uri
if its missing a ? marker.
Ad 2)
This is the most serious problem that bites most people. If they have mistyped
an optional parameter Camel will ignore it and go on. This can lead to users
thinking that Camel runs with that parameter but it does not.
Now Camel barfs and throws a ResolveEndpointFailedException with the list of
unknown parameters.
The example from above but with a mistype in the parameter:
"timer://foo?delay=250&perid=500"
Failed to resolve endpoint: timer://foo?delay=250&perid=500 due to:
org.apache.camel.ResolveEndpointFailedException: Failed to resolve endpoint:
timer://foo?delay=250&perid=500 due to: There are 1 parameters that couldn't be
set on the endpoint. Check the uri if the parameters are spelt correctly and
that they are properties of the endpoint. Unknown parameters=[{perid=500}]
Component Writers
=================
Only in rare cases your component will not work out-of-the-box with Camel 1.4.
In these conditions you need to make sure that you handle the parameters your
component support.
Ïf you have code that handles parameters manually by such as:
parameters.get("size");
You should get and remove the parameter such as:
parameters.get("size");
parameters.remove("size");
or in one-line
Object size = parameters.remove("size");
In Camel 1.4 we have added convenient methods to do this trick; one with a
fallback to a default value if the parameter does not exists. This method does
also the converTo to the requested type. These methods are added on the
DefaultComponent, that most components extend:
public <T> T getAndRemoveParameter(Map parameters, String key, Class<T>
type)
public <T> T getAndRemoveParameter(Map parameters, String key, Class<T>
type, T defaultValue)
Feedback
========
Feedback is most welcome. Any native English speakers could proof read the
exception message as I am sure it "smells".
Also I considered naming the methods getAndRemoveParameter just getParameter
And do you some ideas for even better URI validation that Camel should do
out-of-the-box please feel free to comment here or on the CAMEL-433.
Med venlig hilsen
Claus Ibsen
......................................
Silverbullet
Skovsgårdsvænget 21
8362 Hørning
Tlf. +45 2962 7576
Web: www.silverbullet.dk
