Jmeter 5.5 SMTP Sampler XML配置无法设置邮件头部求助

问题背景 #

我使用以下JMeter测试计划配置（.jmx文件）进行本地性能测试，该配置可正常向localhost:8080发送带8MB附件的邮件，但需要为邮件添加自定义Date头部。

原始测试计划XML：

<?xml version="1.0" encoding="UTF-8"?>
<jmeterTestPlan version="1.2" properties="5.0" jmeter="5.4">
  <hashTree>
    <TestPlan guiclass="TestPlanGui" testclass="TestPlan" testname="Perf Tests" enabled="true">
      <stringProp name="TestPlan.comments"></stringProp>
      <boolProp name="TestPlan.functional_mode">false</boolProp>
      <boolProp name="TestPlan.tearDown_on_shutdown">true</boolProp>
      <boolProp name="TestPlan.serialize_threadgroups">false</boolProp>
      <elementProp name="TestPlan.user_defined_variables" elementType="Arguments" guiclass="ArgumentsPanel" testclass="Arguments" testname="User Defined Variables" enabled="true">
        <collectionProp name="Arguments.arguments"/>
      </elementProp>
      <stringProp name="TestPlan.user_define_classpath"></stringProp>
    </TestPlan>
    <hashTree>
      <ThreadGroup guiclass="ThreadGroupGui" testclass="ThreadGroup" testname="Big - 8mb attachment" enabled="true">
        <stringProp name="ThreadGroup.on_sample_error">continue</stringProp>
        <elementProp name="ThreadGroup.main_controller" elementType="LoopController" guiclass="LoopControlPanel" testclass="LoopController" testname="Loop Controller" enabled="true">
          <boolProp name="LoopController.continue_forever">false</boolProp>
          <stringProp name="LoopController.loops">10</stringProp>
        </elementProp>
        <stringProp name="ThreadGroup.num_threads">5</stringProp>
        <stringProp name="ThreadGroup.ramp_time">5</stringProp>
        <boolProp name="ThreadGroup.scheduler">false</boolProp>
        <stringProp name="ThreadGroup.duration"></stringProp>
        <stringProp name="ThreadGroup.delay"></stringProp>
        <boolProp name="ThreadGroup.same_user_on_next_iteration">true</boolProp>
      </ThreadGroup>
      <hashTree>
        <SmtpSampler guiclass="SmtpSamplerGui" testclass="SmtpSampler" testname="Email - 8mb attachment" enabled="true">
          <stringProp name="SMTPSampler.server">localhost</stringProp>
          <stringProp name="SMTPSampler.serverPort">8080</stringProp>
          <stringProp name="SMTPSampler.serverTimeout">15000</stringProp>
          <stringProp name="SMTPSampler.serverConnectionTimeout">15000</stringProp>
          <stringProp name="SMTPSampler.mailFrom">bobby.hill@hey.com</stringProp>
          <stringProp name="SMTPSampler.replyTo"></stringProp>
          <stringProp name="SMTPSampler.receiverTo">bobby.hill@hey.com</stringProp>
          <stringProp name="SMTPSampler.receiverCC"></stringProp>
          <stringProp name="SMTPSampler.receiverBCC"></stringProp>
          <stringProp name="SMTPSampler.subject">Perf Test - 1 attachment 8mb</stringProp>
          <stringProp name="SMTPSampler.suppressSubject">false</stringProp>
          <stringProp name="SMTPSampler.include_timestamp">false</stringProp>
          <stringProp name="SMTPSampler.message">Hello World - Perf Test!</stringProp>
          <stringProp name="SMTPSampler.plainBody">false</stringProp>
          <stringProp name="SMTPSampler.attachFile">8mb-content-size.pdf</stringProp>
          <stringProp name="SMTPSampler.useSSL">false</stringProp>
          <stringProp name="SMTPSampler.useStartTLS">false</stringProp>
          <stringProp name="SMTPSampler.trustAllCerts">false</stringProp>
          <stringProp name="SMTPSampler.enforceStartTLS">false</stringProp>
          <stringProp name="SMTPSampler.useLocalTrustStore">false</stringProp>
          <stringProp name="SMTPSampler.trustStoreToUse"></stringProp>
          <stringProp name="SMTPSampler.tlsProtocols"></stringProp>
          <boolProp name="SMTPSampler.use_eml">false</boolProp>
          <stringProp name="SMTPSampler.emlMessageToSend"></stringProp>
          <stringProp name="SMTPSampler.useAuth">false</stringProp>
          <stringProp name="SMTPSampler.password"></stringProp>
          <stringProp name="SMTPSampler.username"></stringProp>
          <stringProp name="SMTPSampler.messageSizeStatistics">false</stringProp>
          <stringProp name="SMTPSampler.enableDebug">false</stringProp>
          <collectionProp name="SMTPSampler.headerFields"/>
        </SmtpSampler>
        <hashTree/>
      </hashTree>
    </hashTree>
  </hashTree>
</jmeterTestPlan>

尝试过的配置及问题 #

1. 添加HTTP Header Manager #

在SmtpSampler元素前添加HTTP Header Manager，配置如下：

<HeaderManager guiclass="HeaderPanel" testclass="HeaderManager" testname="HTTP Header Manager" enabled="true">
  <collectionProp name="HeaderManager.headers">
    <elementProp name="Date" elementType="Header">
      <stringProp name="Header.name">Date</stringProp>
      <stringProp name="Header.value">Fri, 21 Nov 1997 09:55:06 -0600</stringProp>
    </elementProp>
  </collectionProp>
</HeaderManager>

问题：无法设置SMTP消息的Date头部，HTTP Header Manager仅对HTTP请求生效，不作用于SMTP Sampler。

2. 用Header类型元素替换headerFields #

将<collectionProp name="SMTPSampler.headerFields"/>替换为以下配置：

<collectionProp name="SMTPSampler.headerFields">
  <elementProp name="Date" elementType="Header">
    <stringProp name="Header.name">Date</stringProp>
    <stringProp name="Header.value">Fri, 21 Nov 1997 09:55:06 -0600</stringProp>
  </elementProp>
</collectionProp>

问题：抛出ClassCastException错误：

java.lang.ClassCastException: class org.apache.jmeter.protocol.http.control.Header cannot be cast to class org.apache.jmeter.config.Argument (org.apache.jmeter.protocol.http.control.Header and org.apache.jmeter.config.Argument are in unnamed module of loader org.apache.jmeter.DynamicClassLoader @372f7a8d)

原因是SMTP Sampler的headerFields集合期望的是Argument类型，而非HTTP的Header类型。

3. 使用Argument类型元素配置 #

尝试用Argument类型配置headerFields：

<collectionProp name="SMTPSampler.headerFields">
  <elementProp name="date" elementType="Argument">
    <stringProp name="Argument.name">Date</stringProp>
    <stringProp name="Argument.value">Fri, 21 Nov 1997 09:55:06 -0600</stringProp>
  </elementProp>
</collectionProp>

问题：配置仍失败，因为缺少了Argument的metadata属性，且elementProp的name需与头部名称一致。

正确配置示例 #

SMTP Sampler的headerFields集合需要使用Argument类型元素，且每个Argument必须包含metadata属性（值设为=即可），同时elementProp的name属性需与头部名称匹配。以下是正确的配置：

替换原SmtpSampler中的<collectionProp name="SMTPSampler.headerFields"/>为：

<collectionProp name="SMTPSampler.headerFields">
  <elementProp name="Date" elementType="Argument">
    <stringProp name="Argument.name">Date</stringProp>
    <stringProp name="Argument.value">Fri, 21 Nov 1997 09:55:06 -0600</stringProp>
    <stringProp name="Argument.metadata">=</stringProp>
  </elementProp>
</collectionProp>

完整的SmtpSampler配置片段：

<SmtpSampler guiclass="SmtpSamplerGui" testclass="SmtpSampler" testname="Email - 8mb attachment" enabled="true">
  <!-- 其他原有配置保持不变 -->
  <stringProp name="SMTPSampler.enableDebug">false</stringProp>
  <collectionProp name="SMTPSampler.headerFields">
    <elementProp name="Date" elementType="Argument">
      <stringProp name="Argument.name">Date</stringProp>
      <stringProp name="Argument.value">Fri, 21 Nov 1997 09:55:06 -0600</stringProp>
      <stringProp name="Argument.metadata">=</stringProp>
    </elementProp>
  </collectionProp>
</SmtpSampler>

该配置会成功为SMTP邮件添加自定义Date头部，解决之前的类型转换错误和配置失效问题。

内容的提问来源于stack exchange，提问作者Simon Tower