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From Pierre Villard <>
Subject Re: Routing File based on CSV header schema
Date Thu, 16 Mar 2017 21:50:29 GMT
Hi Austin,

I believe the RouteOnContent processor won't try to only match the first
line of your flow file but will try to match the whole content. Since your
flow file contains multiple lines, the regular expression you are using
won't work.

I'd do the following: use ExtractText to get the header as an attribute,
and then use RouteOnAttribute and expression language to route the files
with the regular expression you suggested. Here is a gist [1] with a
template I used to test the approach.


Hope this helps,

2017-03-16 21:47 GMT+01:00 Austin Heyne <>:

> Sure, I've stripped things down to eliminate some variables and I think I
> have the problem cornered. I created CSV with a header of "csvA" and
> another with "csvB". I'm matching with regex "^csvA$" and "^csvB$"
> respectively. You may see what the problem is right way. Nifi doesn't seem
> to like '$' as an end of line marker. I've tried both "csvB" and "^csvB"
> which work fine and "csvB$" fails, however, this isn't strict enough for
> our purposes. We may have cases were one file is "col1, col2" and another
> is "col1,col2,col3". This could cause duplicates ingests later eating
> resources. Is there a way to mark the end of line in the regex or am I
> going to have to do a nested regex filter or something else?
> Thanks for the help,
> Austin
> On 03/16/2017 02:27 PM, James Wing wrote:
> Austin,
> I think you are on the right track with RouteOnContent.  Any chance you
> can share a sample CSV header, the settings of your RouteOnContent
> processor, including the regex?
> Thanks,
> James
> On Thu, Mar 16, 2017 at 11:14 AM, Austin Heyne <> wrote:
>> Hi,
>> I have a set of CSV files with headers that utilize various schemas. I'd
>> like to route the CSV files to processors based on the schema set in the
>> header. I've tried using the RouteOnContent processor to sort the files
>> based on "content must contain match" and a regex statement that matches
>> the first line (header). However, this is throwing an 'unmatched' on every
>> file I send through.
>> I've also looked at the ValidateCsv processor but it doesn't appear that
>> works with the header but rather just validates data types. Unfortunately
>> this won't work as columns with the same data type could be in a different
>> order.
>> Is there a ready made solution for this problem that I missed or perhaps
>> a more clever way to approach it?
>> Thanks,
>> Austin Heyne

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