Slf4j Implementation in Gatling inorder to save session values to a external file

Hi All,


I want to write captured regex results from HTTP responses to an external file. I already referred to this link (!topic/gatling/hpUECuX9Fc4) but not able to find a correct syntax. Also I already have TRACE method enabled in logback.xml (attached the logback.xml with this message) it is working fine but since the HTTP responses are really huge , I just want to save specific values within HTTP response to a external file.

For now I am using the below code to write to a file I knew this is not threadsafe and does not support concurrency,

.exec( session => {

val fout = new FileWriter(“CartID.log”, true)

val fileout = new PrintWriter(new BufferedWriter(fout))

fileout.print(session( “cartID” ).as[String])




I got to know that slf4j is a better method that supports concurrency, in this link!topic/gatling/hpUECuX9Fc4 there is a small piece of code showing slf4j implementation within a scala file but that does not seem to work with latest version of Gatling even after importing the following slf4j packages . Looking forward to this forum to help me get away from this issue.

import org.slf4j.Logger._

import org.slf4j.LoggerFactory._



logback.xml (1.24 KB)

In addition to my previous message, I get the below given error messages when trying to compile the following code

val logger = org.slf4j.LoggerFactory.getLogger(this.getClass)
.exec { session => logger.debug(session(“versionNum”).as[String]);
session }


val logger = org.slf4j.LoggerFactory.getLogger(“myDebugLogger”)
.exec(session => {

Compilation errors:

value exec is not a member of org.slf4j.Logger

possible cause: maybe a semicolon is missing before `value exec’?

21926 [main] ERROR io.gatling.compiler.ZincCompiler$ - .exec(session => {

recursive value logger needs type
22158 [main] ERROR io.gatling.compiler.ZincCompiler$ - .exec { session => logger.debug(session(“versionNum”).as[String]);

Hi All,

I was able to successfully implement Slf4j logger in my Gatling script. I browsed through and got the needed solution,

This is how I did the implementation of slf4j,

Following statements should be added to the scala file,

import org.slf4j.Logger._
import org.slf4j.LoggerFactory._

then I added following block of statement to my scala file,

.exec(session => {
val logger = org.slf4j.LoggerFactory.getLogger(this.getClass)"The version number is ********************************************* ") (“versionNum”).as[String])

In addition to this, please ensure you add slf4j-api-1.7.13.jar to your system class path.