Simple Routing Example

[sbuster <st...@hotmail.com>]

I'm new to Camel and I would like some input on the following code I am
trying to write.

Messages arrives on a Queue, and from that queue i would like to open the
message, determine if the message id already exists in a database table, and
if it does then discard the message.  If it does not, then add the message
to the database table.

Would I use a Processor to do the check against the table?
Can I use the JDBC component to do the check, I'm assuming I can use it to
do the insert
How would I stop the route if the record already exist, ie, not continue to
the "insert" endpoint?

would it look something like this
from('jms:queue:myqueue').to(????).to('database insert endpoint?')


Thanks in advance!
Steve

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Re: Simple Routing Example

[Claus Ibsen <cl...@gmail.com>]

On Wed, May 13, 2009 at 1:34 PM, sbuster <st...@hotmail.com> wrote:
>
> I'm new to Camel and I would like some input on the following code I am
> trying to write.
Hi

Welcome on the Camel rider :)

>
> Messages arrives on a Queue, and from that queue i would like to open the
> message, determine if the message id already exists in a database table, and
> if it does then discard the message.  If it does not, then add the message
> to the database table.
>
> Would I use a Processor to do the check against the table?
> Can I use the JDBC component to do the check, I'm assuming I can use it to
> do the insert
> How would I stop the route if the record already exist, ie, not continue to
> the "insert" endpoint?

If you think EIP patterns then there is the filter EIP that is used
for dropping unwanted messages.
http://camel.apache.org/message-filter.html

So the next step would how do we tell the filter if its green or red
light? eg true or false.

You can do this as regular POJO. Eg create a regular Class that has a
method that returns a boolean.

Then you route can be:

from('jms:queue:myqueue')
   .filter().method(MyBean.class, "myMethod")
   .to('database insert endpoint?')

Where MyBean is your POJO.

If you use Spring XML for defining beans etc. Then you can refer to a
spring bean by its id
   .filter().method("myBeanId", "myMethod")

And with Spring XML you can dependency inject your bean to get a
DataSource so you can do some SQL to test
whether the message exists or not.

The signature of your method can be kinda anything as Camel uses Bean Binding.
http://camel.apache.org/bean-binding.html


So if the JMS payload is String based you can just define it as

boolean myMethod(String body) {
   // do some SQL to see if the message exists
   return true or false;
}




>
> would it look something like this
> from('jms:queue:myqueue').to(????).to('database insert endpoint?')
>
>
> Thanks in advance!
> Steve
>
> --
> View this message in context: http://www.nabble.com/Simple-Routing-Example-tp23520058p23520058.html
> Sent from the Camel - Users mailing list archive at Nabble.com.
>
>



-- 
Claus Ibsen
Apache Camel Committer

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