Jmeter :To extract the response of an HTTP Sampler into a variable for later use

To extract the response of an HTTP Sampler into a variable for later use

To add regular expression extractor element to a test plan in JMeter:

1.   Right click the sampler element (request to the server from which the value needs to be extracted)

2. Select Add option à Post Processors à Regular expression extractor

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Extracting Single string from the response

Consider an example, where a user Date displayed in a webpage Ex: Date:xxxxxxx

In order to extract the username, below R.E can be used:    

Reference Name:                   Date

Regular Expression:               Date\:(.+?)             

Template:                                 $1$

Match No. (0 for Random):    1

Default Value:                          match not found

Note:The special characters above mean:

(  ) encloses the portion of the match string to be returned

. ->  match for any character.    +  è one or more times.

?  stop when first match is found 

Without the ?, the .+ would continue until it finds the last possible match.

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Extracting Multiple Strings from the response

Consider a scenario where the user wants to extract Date and Time.
(Ex:Date:xxxxxx Time:xxxxxxx) To extract both the ids, the below R.E can be used

                       Reference Name:                    Date_time

                       Regular Expression:    Date\: (.+?) Time\:(.+?)

                      Template:                                $1$$2$

                      Match No. (0 for Random):    1

                      Default Value:            match not found

Since we need to extract two values from the response, two groups are created. So the template has $1$$2$. The JMeter Regex Extractor saves the values of the groups in additional variables.

The following variables would be set as:

    Date_time-> xxxxxzzzz

    Date_time _g0 ->  Date:xxxx time:zzzz

    Date_time _g1 -> xxxx

    Date_time _g2 ->  zzzz

These variables can be later referred in the JMeter test plan, as ${Date_time _g1}, ${Date_time _g2}.

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Extracting only numbers from the String

Consider a case where we need to only extract the numbers, for example price=100$

To extract 100, the below R.E can be used

                      Reference Name:                    price

                      Regular Expression:    price= “(.+?)$”

                      Template:                                $1$

                      Match No. (0 for Random):    1

                      Default Value:            match not found