JMeter: How to know why my regular expression extractor in JMeter is not extracting the data

Question

I would like to know why regular expression extractor in JMeter is not extracting the data after parameterization. Response message: Internal Server Error

Expression added are:

1. name="__EVENTVALIDATION" id="__EVENTVALIDATION" value="(.+?)"

2. name="__VIEWSTATE" id="__VIEWSTATE" value="(.+?)"

POST data:
__VIEWSTATE=%24%7BviewState%7D&__EVENTVALIDATION=%24%7BeventValidation%7D&txtUserID=1001201&txtPWD=CFL&BtnSubmit=Submit&hdnE=5&hdnN=323&hdnD=173

Answer 1

Your regexp is probably wrong.

To debug it, run your test then use View Results Tree and select Regexp Tester:

You can then test your regexps and see what happens.

As I don't have the response content that contains the 2 tokens, I can only guess that regexp should be :

• name="__EVENTVALIDATION" id="__EVENTVALIDATION" value="([^"]+?)" , see https://regex101.com/r/aG1gX2/1

• name="__VIEWSTATE" id="__VIEWSTATE" value="([^"]+?)" , see https://regex101.com/r/iM5cZ3/1