如何在Gatling中从Feeder注入JSON至请求Body中

Got it, let's fix this up. The issue with your current code is that RawFileBody is meant to load static file content directly, but you need to dynamically generate a JSON body using the id value from your feeder. Here are two straightforward ways to achieve this:

Option 1: Use StringBody to Construct JSON Directly #

Since your feeder provides an id value for each user, you can build the JSON body directly using Gatling's expression language to reference the feeder value:

.body(StringBody("""{"id":"${id}"}"""))

Triple quotes let you write the JSON string without escaping inner quotes, and ${id} pulls the current user's id from the feeder automatically.

Option 2: Use ElFileBody with a Template File #

If you prefer keeping the JSON structure in a separate file (ideal for more complex bodies), create a template file (e.g., src/test/resources/json/gatling/request-template.json) with this content:

{"id":"${id}"}

Then reference this template in your request:

.body(ElFileBody("json/gatling/request-template.json"))

Gatling will replace the ${id} placeholder with the feeder's value for each user.

Full Modified Code #

Here's your updated simulation class using Option 1 (swap in Option 2 if you prefer the template approach):

import io.gatling.core.Predef._
import io.gatling.http.Predef._
import scala.concurrent.duration._

class BasicSimulation extends Simulation {
  val httpConf = http
    .baseURL("http://localhost:8099")
    .headers(Map("Content-Type" -> "application/json"))
    .doNotTrackHeader("1")
    .acceptLanguageHeader("en-US,en;q=0.5")
    .acceptEncodingHeader("gzip, deflate")
    .userAgentHeader("Mozilla/5.0 (Windows NT 5.1; rv:31.0) Gecko/20100101 Firefox/31.0")

  val feeder = jsonFile("src/test/resources/json/gatling/test.json")

  val scnPost = scenario("BasicSimulation")
    .feed(feeder)
    .exec(http("request_1")
      .post("/spring-test")
      // Use either StringBody or ElFileBody here
      .body(StringBody("""{"id":"${id}"}"""))
      .check(status.is(200)))

  setUp(
    scnPost.inject(constantUsersPerSec(3) during(3 seconds))
  ).protocols(httpConf)
}

How It Works #

• The .feed(feeder) step loads each entry from your JSON array into the user's session, making the id value accessible via ${id}.
• Both StringBody and ElFileBody support Gatling's expression language, so they resolve the ${id} placeholder to the actual feeder value for every user request.

内容的提问来源于stack exchange，提问作者a.moussa