question Re: How to apply replaceAll to ${path} on NiFi? in Support Questions

How to apply replaceAll to ${path} on NiFi?

MarcioMarchiori — Thu, 09 Dec 2021 17:11:28 GMT

Hello!

I'm getting files from a SMB with GetSMBFile, eventually they'll be placed on S3 with PutS3Object, the problem is the path contains "\" on it and I need to replace all of those to "/", I attempted a simple ${path:replaceAll('\','//')}/${filename} on the Object Key but it didn't work.

What's the proper way to do this on NiFi?

Re: How to apply replaceAll to ${path} on NiFi?

MattWho — Thu, 09 Dec 2021 19:55:46 GMT

@MarcioMarchiori

Depending on which NiFi Expression Language (NEL) function you are using, either of the following two NEL statements should work for you:

${path:replaceAll("\\\\",'/')}/${filename}

In above you are using the replaceAll function which expects a java regular expression. Since '\" is an escape character and NiFi is a java application, the first \ escapes the second \ and the third \ escapes the forth \. So \\\\ results in a regex of \\ being applied against the value present in the "path" variable.

${path:replace('\\','/')}/${filename}

In above you are using the replace function which does not path the first argument to be evaluated as a java regular expression but rather takes a string literal. And since '\' is an escape character you need \\ which tells java to treat the second \ as the literal string value to search for.

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Thank you,

Matt

Re: How to apply replaceAll to ${path} on NiFi?

MarcioMarchiori — Fri, 10 Dec 2021 03:00:28 GMT

Thanks mate, I had completely forgotten about the need for the need for the '\\\\', that solved it.