(Simple?) Why is my rescue clause not catching an exception?

[Wes Gamble]

All,

I'm using the Net::HTTP module to fetch resources from the Internet in a
Rails application.

I have a method that does the HTTP request and this action is enclosed
in a begin/rescue/end block. However, when I just did a request and the
Internet connectivity went down for a second, the call to
"http.request(req)" failed and I didn't see my rescue block get
executed. Instead, it appears that the original exception (from
timeout.rb) just bubbles all of the way up the stack and my rescue
doesn't seem to catch it.

Is this because the call to http.request is inside of it's own block and
I would need to place a rescue clause in there?

Here's the guts of my method:

begin
if (theURL.instance_of?(URI::HTTP))
req = Net::HTTP::Get.new(theURL.request_uri())
res = Net::HTTP.start(theURL.host, theURL.port) {|http|
http.request(req)
}
end
rescue
raise("Unable to get page - please check the URL")
end

Thanks,
Wes

 

[Robert Klemme]

All,

I'm using the Net::HTTP module to fetch resources from the Internet in a
Rails application.

I have a method that does the HTTP request and this action is enclosed
in a begin/rescue/end block. However, when I just did a request and the
Internet connectivity went down for a second, the call to
"http.request(req)" failed and I didn't see my rescue block get
executed. Instead, it appears that the original exception (from
timeout.rb) just bubbles all of the way up the stack and my rescue
doesn't seem to catch it.

Is this because the call to http.request is inside of it's own block and
I would need to place a rescue clause in there?

Here's the guts of my method:

begin
if (theURL.instance_of?(URI::HTTP))
req = Net::HTTP::Get.new(theURL.request_uri())
res = Net::HTTP.start(theURL.host, theURL.port) {|http|
http.request(req)
}
end
rescue
raise("Unable to get page - please check the URL")
end

Thanks,
Wes

rescue catches StandardError by default only and the exception thrown by
Net::HTTP is likely some other type not inheriting standard error.
=> [StandardError, Exception, Object, Kernel]

You need

rescue Exception

Kind regards

robert