Re: How to negate a Predicate?

[Hadrian Zbarcea]

Please note that the generics will stay as is on the camel-1.x branch,  
so upgrading to 1.6.0 will not help with that.


Hadrian

On Feb 17, 2009, at 11:55 PM, Claus Ibsen wrote:


Hi

All that generics fuss is fixed in Camel 2.0 as part of our API  
cleanup.


Glad its working for you and the route is easier to read.


On Wed, Feb 18, 2009 at 2:54 AM, Trevv 4...@safe-mail.net wrote:


Thanks Claus, that's a good idea.  Using import static makes the  
usage of

PredicateBuilder.not much easier to read.

When I use your code as-is, I get these warnings:


Type safety: Unchecked invocation not(Predicate) of the generic  
method

not(PredicateE) of type PredicateBuilder


Type safety: The expression of type Predicate needs unchecked  
conversion

to conform to PredicateE


in Camel 1.5.0.  It's too late in my release cycle to upgrade to  
Camel 1.6.0
now.  But that's OK; I can avoid those warnings by using  
Builder.header

instead of BuilderSupport.header.

My code now looks like this:

  choice().
when(not(Builder.
   header(foo).
 regex(cheese|whey)))

which is much easier to read than before.
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--
Claus Ibsen
Apache Camel Committer

Open Source Integration: http://fusesource.com
Blog: http://davsclaus.blogspot.com/

Re: How to negate a Predicate?

[Claus Ibsen]

Hi

I will add a sample to the predicate wiki page
http://camel.apache.org/predicate.html

But there is a hikup with the apache server right now, so here is part
of the source code for an unit test:

import static org.apache.camel.builder.PredicateBuilder.not;

...

protected RouteBuilder createRouteBuilder() {
return new RouteBuilder() {
public void configure() {
// START SNIPPET: e1
from(direct:start)
.choice()

.when(not(header(username).regex(goofy|pluto))).to(mock:people)
.otherwise().to(mock:animals)
.end();
// END SNIPPET: e1
}
};
}


On Tue, Feb 17, 2009 at 5:01 AM, Trevv 4...@safe-mail.net wrote:

 Most of my uses of .when are like the first snippet below, very easy to read.

 But I have a few uses of .when which need to negate the Predicate, and in
 those places I'm using code like the second snippet below.  It works well,
 and there are no compiler warnings, but it is NOT easy to read.  How should
 I make this code easier to read?

// take the first branch, if the regex DOES match...

choice().
  when(header(foo).
 regex(cheese|whey))



// take the first branch, if the regex DOES NOT match...

choice().
  when(PredicateBuilder.
 not(Builder.
   MinaExchangeheader(foo).
 regex(cheese|whey)))
 --
 View this message in context: 
 http://www.nabble.com/How-to-negate-a-Predicate--tp22049751s22882p22049751.html
 Sent from the Camel - Users mailing list archive at Nabble.com.





-- 
Claus Ibsen
Apache Camel Committer

Open Source Integration: http://fusesource.com
Blog: http://davsclaus.blogspot.com/