Capture time difference between values of two regular expression reference names in Jmeter - jmeter

Question

I defined regular expressions in my JMeter test plan and I'm able to capture the values in simple variables in user.variables. But I'm trying to calculate the time difference between two variables as follows in Beanshell post processor and I'm not getting any result in my report.
import javax.xml.bind.DatatypeConverter;
vars.put("old_date_submitted", "submittedDate"); // submittedDate, succeeddedDate and runningDates are regular expr. reference names
vars.put("old_date_succeeded", "succeededDate");
vars.put("old_date_running", "runningDate");
Calendar cal_s = DatatypeConverter.parseDateTime(vars.get("old_date_submitted"));
Calendar cal_c = DatatypeConverter.parseDateTime(vars.get("old_date_succeeded"));
Calendar cal_r = DatatypeConverter.parseDateTime(vars.get("old_date_running"));
Date new_date1 = cal_s.getTime(); // submitted Time
Date new_date2 = cal_c.getTime(); // succeeded Time
Date new_date3 = cal_r.getTime(); // running Time
long new_date1_ms = new_date1.getTime(); // submitted Time
long new_date2_ms = new_date2.getTime();
long new_date3_ms = new_date3.getTime();
log.info("Date in milliseconds: " + new_date1_ms);
long delta1 = new_date2_ms - new_date1_ms; //calculate the difference (succeededDate - submittedDate)
long delta2 = new_date3_ms - new_date1_ms; //calculate the difference (runningDate - submittedDate)
vars.put("delta1", String.valueOf("delta1")); // store the result into a JMeter Variable
vars.put("delta2", String.valueOf("delta2")); // store the result into a JMeter Variable

Answer 1

This bit:
vars.put("old_date_submitted", "submittedDate"); // submittedDate, succeeddedDate and runningDates are regular expr. reference names
vars.put("old_date_succeeded", "succeededDate");
vars.put("old_date_running", "runningDate");
seems odd to me. Given:
submittedDate, succeeddedDate and runningDates are regular expr. reference names
My expectation is that you should be using JMeter Variables instead of hardcoded strings there, so you should change your code to look like:
vars.put("old_date_submitted", vars.get("submittedDate")); // submittedDate, succeeddedDate and runningDates are regular expr. reference names
vars.put("old_date_succeeded", vars.get("succeededDate"));
vars.put("old_date_running", vars.get("runningDate"));
So most likely your code is failing at DatatypeConverter.parseDateTime.
Next time you face any problem with your Beanshell scripts consider the following troubleshooting techniques:
Check jmeter.log file - in case of Beanshell script failure the error will be printed there
Add debug(); directive to the very beginning of your Beanshell script - it will trigger debugging output to stdout
Put your Beanshell code in try/catch block like:
try {
//your code here
}
catch (Throwable ex) {
log.error("Something went wrong", ex);
throw ex;
}
This way you get more "human-friendly" stacktrace printed to jmeter.log file.
See How to Use BeanShell: JMeter's Favorite Built-in Component guide for more information on using Beanshell in JMeter tests.