51工具盒子英文:
How to calculate a variable and send it as a header in jmeter
问题 {#heading}
我正在尝试计算一个变量的值，以便将该值作为JMETER头部发送，类似于这样：
```java
Date timestamp = new Date();
String now = DateUtils.toIso8601Date(timestamp);
vars.put("timestamp", "hello");
我将此代码放在一个beanshell预处理器中，然后在头部管理器中使用以下语法，希望将时间戳作为头部发送：
然而，变量的值并未在头部替换。在接下来的步骤中，我希望能够使用代码来计算HMAC签名并将其作为头部发送。在jmeter中是否有任何方法可以实现这一点？可以使用脚本来计算头部值，然后发送吗？我在postman中使用了预先脚本来做到这一点，但在jmeter中我没有看到类似的机制。
谢谢
<details>
<summary>英文:</summary>
I am trying to calculate a variable value in order to send that value as a header in JMETER, something like this:
Date timestamp = new Date();
String now = DateUtils.toIso8601Date(timestamp);
vars.put("timestamp", "hello");
I put this code in a beanshell preprocessor and then used the following syntax in a header manager hoping to send the timestamp as a header:
\[\]http://static.51tbox.com/static/2024-11-29/col/1a186d47c9d5642c87f75468603628c9/0fa55de13081485a9b403b47d01da72a.png.jpg
However the value of the variable is not being replaced in the header. Further down the line I want to be able to use code to calculate an HMAC signature and send it as a header. Is there any way to do this in jmeter? use a script to calculate a header value and then send it? I\'ve done this in postman with the pre-req scripts but I don\'t see a similar mechanism in jmeter.
Thanks
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答案1
===
得分: 1
1.
这个 `DateUtils.toIso8601Date` 函数是我不熟悉的，它既不在http://static.51tbox.com/static/2024-11-29/col/1a186d47c9d5642c87f75468603628c9/0fa55de13081485a9b403b47d01da72a.png.jpg中，也不在随JMeter一起提供的库中。如果你正在使用一个自定义库来提供这个函数，你需要：
* 将它复制到https://jmeter.apache.org/usermanual/get-started.html#classpath
* 重新启动JMeter以加载它
* 添加一个https://docs.oracle.com/javase/tutorial/java/package/usepkgs.html语句来加载它
2.
https://jmeter.apache.org/usermanual/best-practices.html#bsh_scripting，特别是涉及到"重型"任务，比如加密操作时，请考虑迁移。更多信息：https://www.blazemeter.com/blog/beanshell-vs-jsr223-vs-jmeter
\<details\>
\<summary\>英文:\</summary\>
1.
This `DateUtils.toIso8601Date` function is not something I\'m aware of, it\'s neither present in http://static.51tbox.com/static/2024-11-29/col/1a186d47c9d5642c87f75468603628c9/0fa55de13081485a9b403b47d01da72a.png.jpg nor in libraries which come with JMeter. If you\'re using a custom library which provides this function you will need to:
* copy it to https://jmeter.apache.org/usermanual/get-started.html#classpath
* restart JMeter to pick it up
* add an https://docs.oracle.com/javase/tutorial/java/package/usepkgs.html statement to load it
2.
https://jmeter.apache.org/usermanual/best-practices.html#bsh_scripting especially when it comes to \"heavy\" tasks like cryptographic operations so consider migrating. More information: https://www.blazemeter.com/blog/beanshell-vs-jsr223-vs-jmeter
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