topic Re: [resolved] How to extract substrings according to regex pattern in tMap in Talend Studio

[resolved] How to extract substrings according to regex pattern in tMap

Anonymous — Sat, 16 Nov 2024 13:29:44 GMT

Hi,
i am new to Talend, and I trouble my mind how to perform Regex string manipulations in tMap.
Situation is: I have a column that has some date information embedded in text like this:
"AC/DC tickets for 20/12/2010"
Here i want to extract the date. My first approach was to utilise tExtraxctRegExFields, but since "cylces" in data flow are not supportet i dont see a way to rejoin this column with the rest of the dataset once it is split up.
I found a regex pattern
"({2}/{2}/{4})"
identifying the date, but here is my question: What is the correct java statement / code i have to create in tMap expression builder for this column? I tried Pattern.compile() but could not find a valid and working construction.
The source column holds the whole string, destination column should be stripped down to the date as a substring according to the regex pattern.
I use TOS 4.0.
Any help is appreciated.
Thanks
dexter

Re: [resolved] How to extract substrings according to regex pattern in tMap

Anonymous — Sun, 21 Mar 2010 16:12:51 GMT

Hi,
You can use the tExtractRegexFields component with this pattern : "^(.+)({2})/({2})/({4})$"
On your output shema you have just to declare 4 columns :
- text
- day
- month
- year
And that's all.

Re: [resolved] How to extract substrings according to regex pattern in tMap

Anonymous — Sun, 21 Mar 2010 17:39:48 GMT

Hi eguerin,
thanks for the quick reply and the improved regex
tExtractRegexFields isnt the best choice for me here, since it can only split up one column at a time as i see, and i have more than 1 column that needs some string cleansing in the data flow.
I have figured out that there are posts dealing with similar problems:
https://community.talend.com/t5/Design-and-Development/resolved-Using-TMap-to-parse-complex-string/td-p/113699
It suggests RegEx String manipulations can be done in tMap which would be very elegant. But how exactly is the java statement to extract a substring from a given input string using a defined regex pattern? Should i write into code directly or can i implement it in the tmap expression builder?
Thanks
dexter

Re: [resolved] How to extract substrings according to regex pattern in tMap

Anonymous — Sun, 21 Mar 2010 17:45:11 GMT

Ok, you can do this with a routine (into the menu Code > Routines).
You have to create a new routine and develop your code in Java.
After this, you're able to reuse your routine into de expression builder (into the tMap) like this :
routines.yourRoutineName.yourMethodName(param1, paramx)
It's very easy to create a new routine.

Re: [resolved] How to extract substrings according to regex pattern in tMap

Anonymous — Sun, 21 Mar 2010 21:12:25 GMT

thanks,
custom code sounds like a good option. Ill give it a try..
/wave
dexter