scala - 如何在 Gatling 中动态生成 JSon？

Question

我有以下两种方法:

def randomStartMethod() : Long = {
  var range = 1000L
  var r = ThreadLocalRandom.current().nextLong(10L*range)
  var randomStart = 1396024675000L + r
  return randomStart
}

def randomStopMethod() : Long = {
  var range = 1000L
  val r = ThreadLocalRandom.current().nextLong(10L*range)
  val randomStop =  1396024675000L + r*2L
  return randomStop
}

然后我将它添加到请求正文中，如下所示:

val activity = repeat(10, "i") {
      exec(http("POST activity post")
        .post("/activity/")
        .header("Content-Type", "application/json; charset=ISO-8859-1")
        .header("accept", "*/*")
        .body(StringBody(
          s"""
             |{
             |    "id": "activityId",
             |    "type": "run",
             |    "start_epoch_ms": "${randomStartMethod()}",
             |    "end_epoch_ms": "${randomStop()}",
             |    "metrics": [
             |        {
             |            "type": "distance",
             |            "unit": "KM",
             |            "source": "nike.running.ios",
             |            "values": [
             |                {
             |                    "start_epoch_ms": "${randomStartMethod()}",
             |                    "end_epoch_ms": "${randomStopMethod()}",
             |                    "value": 2.0
             |                }
             |
            |            ]
             |        }
             |    ]
             |}
          """.stripMargin)).
        asJSON
        .check(status.is(202))
        .check(
          jsonPath(
            "$.activityId").saveAs("message")
        )
        .check(bodyString.
          transform(_.split("\""
          )(3)).saveAs(
          "changeToken"))

      ).exec(
        session => {
          val maybeId =
            session.get(
              "message").asOption[String]
          println(maybeId)
          session
        }
      )
    }
  }

但是在这里，当我与提要一起使用时，这些值不是动态生成的。有人可以建议如何在整个运行过程中每次生成随机数吗？

Answer 1

请记住:如果您希望某些代码不仅在 Gatling 构建场景时在启动时评估一次，而且每次虚拟用户执行操作时都被评估，则您必须传递动态内容:基于 Gatling EL 的字符串或函数。

在这里，您必须执行后者，例如:

.body(StringBody(session => //THIS IS A FUNCTION
          s"""
             |{
             |    "id": "activityId",
             |    "type": "run",
             |    "start_epoch_ms": "${randomStartMethod()}",
             |    "end_epoch_ms": "${randomStop()}",
             |    "metrics": [
             |        {
             |            "type": "distance",
             |            "unit": "KM",
             |            "source": "nike.running.ios",
             |            "values": [
             |                {
             |                    "start_epoch_ms": "${randomStartMethod()}",
             |                    "end_epoch_ms": "${randomStopMethod()}",
             |                    "value": 2.0
             |                }
             |
             |            ]
             |        }
             |    ]
             |}
          """.stripMargin))