Hi See about deep-clone at: http://camel.apache.org/multicast
On Thu, Jul 14, 2016 at 6:54 PM, Matt Sicker <boa...@gmail.com> wrote: > I think I found my issue with the mutable headers in question. It appears > that the headers of a message are shared amongst the exchanges sent out in > a multicast, so modifying a header in one route affects the other route. If > that's not the case, then I've discovered some very strange behavior. > > On 6 July 2016 at 20:34, Tadayoshi Sato <sato.tadayo...@gmail.com> wrote: > >> Hi, >> >> It's just an idea off the top of my head, but what about providing a parity >> check header in company with the header you want to be immutable. I.e. >> >> YOUR_HEADER = "Do not change!" >> YOUR_HEADER_MD5 = "fef4de21954d4b9f1b3e61ed153799da" >> >> or >> >> YOUR_HEADER_HASH = "md5:fef4de21954d4b9f1b3e61ed153799da" >> >> When making use of this header, you can always validate if it's not changed >> in the routes. >> >> On Wed, Jul 6, 2016 at 6:03 AM, Matt Sicker <boa...@gmail.com> wrote: >> >> > Let me give a more specific use case. Path parameters from rest-dsl are >> > passed in as message headers. I don't want any route to accidentally >> > overwrite or modify those headers as they're useful for the entire >> > lifecycle of that message. >> > >> > On 5 July 2016 at 16:00, Matt Sicker <boa...@gmail.com> wrote: >> > >> > > The exact use case is preventing developers from [inadvertently] >> > modifying >> > > headers or properties that are used before and after a particular >> > subroute. >> > > >> > > On 5 July 2016 at 15:57, souciance <souciance.eqdam.ras...@gmail.com> >> > > wrote: >> > > >> > >> I guess the question is, why would different routes split over >> different >> > >> bundles want to write over the same header/property? What's the case >> > here? >> > >> Surely it cannot be just to prevent accidents by developers because >> what >> > >> would be their reason to write over that header? >> > >> >> > >> I think it is better to agree on a naming and some sort of other >> > >> convention >> > >> and stick to that because I don't think there is a way to to make a >> > header >> > >> immutable. I guess an ugly solution would be to save the header in a >> map >> > >> and give the key name something very unique. >> > >> >> > >> On Tue, Jul 5, 2016 at 10:48 PM, Matt Sicker [via Camel] < >> > >> ml-node+s465427n578481...@n5.nabble.com> wrote: >> > >> >> > >> > Please let me know if you think of anything! >> > >> > >> > >> > On 5 July 2016 at 15:16, Brad Johnson <[hidden email] >> > >> > <http:///user/SendEmail.jtp?type=node&node=5784811&i=0>> wrote: >> > >> > >> > >> > > I certainly understand the impulse and think it is spot on but >> can't >> > >> > think >> > >> > > of how to do it with headers. Claim checks might work but they >> are >> > >> > really >> > >> > > for reducing overhead of data and not for locking like that but >> that >> > >> > might >> > >> > > be a viable solution depending on the exact problem. >> > >> > > >> > >> > > Thanks Matt, this is going to be stuck in my head now. I'll >> > probably >> > >> > dream >> > >> > > of an answer of some sort tonight. >> > >> > > >> > >> > > Brad >> > >> > > >> > >> > > On Tue, Jul 5, 2016 at 3:02 PM, Matt Sicker <[hidden email] >> > >> > <http:///user/SendEmail.jtp?type=node&node=5784811&i=1>> wrote: >> > >> > > >> > >> > > > My use case is basically to help prevent bugs where a header or >> > >> > exchange >> > >> > > > property gets modified. Some of my routes in question branch out >> > >> into >> > >> > > > several different bundles, and it is difficult to enforce >> > contracts >> > >> > that >> > >> > > > way amongst several developers with varying levels of Camel >> > >> expertise. >> > >> > > > Similar to how one might use final variables to prevent people >> > from >> > >> > > > reassigning them, this could be a final header that prevents >> > people >> > >> > from >> > >> > > > reusing them for things. >> > >> > > > >> > >> > > > On 5 July 2016 at 14:22, Brad Johnson <[hidden email] >> > >> > <http:///user/SendEmail.jtp?type=node&node=5784811&i=2>> >> > >> > > > wrote: >> > >> > > > >> > >> > > > > That's what I figured. I'd have to look at the Map >> > implementation >> > >> > of >> > >> > > the >> > >> > > > > exchange but as far as I know there isn't a way to make it a >> > write >> > >> > once >> > >> > > > > only operation. It's just a map of some sort. There might >> be a >> > >> way >> > >> > to >> > >> > > > do >> > >> > > > > it with transactions but I'm not an expert there. I generally >> > use >> > >> > > > headers >> > >> > > > > but in reality should probably be using exchange properties >> more >> > >> > often. >> > >> > > > > >> > >> > > > > >> > >> > > > > >> > >> > > > >> > >> > > >> > >> > >> > >> >> > >> http://stackoverflow.com/questions/10330998/passing-values-between-processors-in-apache-camel >> > >> > > > > >> > >> > > > > Almost any mechanism I can think of off the top of my head >> could >> > >> be >> > >> > > > > subverted by someone who wanted to or who didn't understand >> that >> > >> the >> > >> > > > value >> > >> > > > > associated with the bean shouldn't be modified. For example, >> > you >> > >> > could >> > >> > > > > create a bean that you associate with your header that stores >> > data >> > >> > but >> > >> > > > also >> > >> > > > > returns a UUID. That UUID could be stored in another header >> and >> > >> > > sometime >> > >> > > > > later in the routes you could verify that the bean stored >> under >> > >> your >> > >> > > key >> > >> > > > > returns the same UUID as the header indicates. But that >> > wouldn't >> > >> > stop >> > >> > > > > someone from changing the bean stored to the key and it >> wouldn't >> > >> > > prevent >> > >> > > > > them from updating the UUID to a new bean they might create. >> > >> > > > > >> > >> > > > > On Tue, Jul 5, 2016 at 1:49 PM, Matt Sicker <[hidden email] >> > >> > <http:///user/SendEmail.jtp?type=node&node=5784811&i=3>> wrote: >> > >> > > > > >> > >> > > > > > I'm thinking of an idea to prevent a header from being >> > modified >> > >> by >> > >> > > > other >> > >> > > > > > parts of the route. A sort of contract if you will. >> > >> > > > > > >> > >> > > > > > On 5 July 2016 at 13:01, Brad Johnson <[hidden email] >> > >> > <http:///user/SendEmail.jtp?type=node&node=5784811&i=4>> >> > >> > > > > > wrote: >> > >> > > > > > >> > >> > > > > > > Is there another part of your process that is specifically >> > >> > changing >> > >> > > > the >> > >> > > > > > > header or are you more concerned about it being >> consistently >> > >> > there >> > >> > > > > across >> > >> > > > > > > routes? Nothing will change it automatically if it is >> your >> > >> > header. >> > >> > > > I >> > >> > > > > > > don't remember the actual implementation but conceptually >> it >> > >> is >> > >> > > just >> > >> > > > a >> > >> > > > > > > hastable/map with key/values. If you set header with some >> > >> > specific >> > >> > > > key >> > >> > > > > > > then nothing else will change it. >> > >> > > > > > > >> > >> > > > > > > As an example, I use a camel splitter and then set a >> header >> > >> with >> > >> > > the >> > >> > > > > > > splitter index so that I can use it in another route later >> > to >> > >> > > > > reassemble >> > >> > > > > > > with the resequencer. >> > >> > > > > > > >> > >> > > > > > > <split> >> > >> > > > > > > <simple>${body}</simple> >> > >> > > > > > > <setHeader headerName="seqnum"> >> > >> > > > > > > <simple>exchangeProperty.CamelSplitIndex</simple> >> > >> > > > > > > </setHeader> >> > >> > > > > > > ... >> > >> > > > > > > >> > >> > > > > > > The "seqnum" is just a key that I'm defining. I could >> > >> obviously >> > >> > > call >> > >> > > > > it >> > >> > > > > > > anything "sequenceNumber" or whatever but when I access it >> > >> later >> > >> > > that >> > >> > > > > > > header is available on the exchange. If I explicitly >> change >> > >> what >> > >> > > the >> > >> > > > > map >> > >> > > > > > is >> > >> > > > > > > storing for "seqnum" then it will be different because I >> > can't >> > >> > make >> > >> > > > the >> > >> > > > > > > header map itself immutable. >> > >> > > > > > > >> > >> > > > > > > >> > >> > > > > > > On Tue, Jul 5, 2016 at 10:33 AM, Matt Sicker <[hidden >> email] >> > >> > <http:///user/SendEmail.jtp?type=node&node=5784811&i=5>> >> > >> > > > wrote: >> > >> > > > > > > >> > >> > > > > > > > As in once I set the header, nothing can change the >> header >> > >> > during >> > >> > > > the >> > >> > > > > > > > lifecycle of the message during a route. Same for an >> > >> exchange >> > >> > > > > property. >> > >> > > > > > > > >> > >> > > > > > > > -- >> > >> > > > > > > > Matt Sicker <[hidden email] >> > >> > <http:///user/SendEmail.jtp?type=node&node=5784811&i=6>> >> > >> > > > > > > > >> > >> > > > > > > >> > >> > > > > > >> > >> > > > > > >> > >> > > > > > >> > >> > > > > > -- >> > >> > > > > > Matt Sicker <[hidden email] >> > >> > <http:///user/SendEmail.jtp?type=node&node=5784811&i=7>> >> > >> > > > > > >> > >> > > > > >> > >> > > > >> > >> > > > >> > >> > > > >> > >> > > > -- >> > >> > > > Matt Sicker <[hidden email] >> > >> > <http:///user/SendEmail.jtp?type=node&node=5784811&i=8>> >> > >> > > > >> > >> > > >> > >> > >> > >> > >> > >> > >> > >> > -- >> > >> > Matt Sicker <[hidden email] >> > >> > <http:///user/SendEmail.jtp?type=node&node=5784811&i=9>> >> > >> > >> > >> > >> > >> > ------------------------------ >> > >> > If you reply to this email, your message will be added to the >> > discussion >> > >> > below: >> > >> > >> > >> > >> > >> >> > >> http://camel.465427.n5.nabble.com/Is-it-possible-to-make-a-message-header-or-property-immutable-tp5784800p5784811.html >> > >> > To start a new topic under Camel - Users, email >> > >> > ml-node+s465427n465428...@n5.nabble.com >> > >> > To unsubscribe from Camel - Users, click here >> > >> > < >> > >> >> > >> http://camel.465427.n5.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=465428&code=c291Y2lhbmNlLmVxZGFtLnJhc2h0aUBnbWFpbC5jb218NDY1NDI4fDE1MzI5MTE2NTY= >> > >> > >> > >> > . >> > >> > NAML >> > >> > < >> > >> >> > >> http://camel.465427.n5.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml >> > >> > >> > >> > >> > >> >> > >> >> > >> >> > >> >> > >> -- >> > >> View this message in context: >> > >> >> > >> http://camel.465427.n5.nabble.com/Is-it-possible-to-make-a-message-header-or-property-immutable-tp5784800p5784812.html >> > >> Sent from the Camel - Users mailing list archive at Nabble.com. >> > > >> > > >> > > >> > > >> > > -- >> > > Matt Sicker <boa...@gmail.com> >> > > >> > >> > >> > >> > -- >> > Matt Sicker <boa...@gmail.com> >> > >> > > > > -- > Matt Sicker <boa...@gmail.com> -- Claus Ibsen ----------------- http://davsclaus.com @davsclaus Camel in Action 2: https://www.manning.com/ibsen2
