JMeter WebDriver Sampler无法运行求助（多浏览器报错）

问题概述 #

使用JMeter的WebDriver Sampler自动化应用时，Chrome、Gecko、Chromium Driver均出现报错，核心错误为java.lang.NoClassDefFoundError: Could not initialize class org.openqa.selenium.remote.http.netty.NettyClient；Chromium浏览器虽能启动，但会触发超时错误。

环境版本 #

• JMeter：5.3
• Java：17.0.6 LTS
• Chrome Driver：120（对应Chrome浏览器120.0）
• WebDriver版本：4.13.0

示例脚本（BeanShell） #

var driverHandler = JavaImporter(org.openqa.selenium, org.openqa.selenium.support.ui);
var sleepSynchronizer = new driverHandler.WebDriverWait(WDS.browser, 5000);

driverHandler.sampleResult.sampleStart();
//Render the home Page
WDS.browser.get('<application URL>');
sleepSynchronizer.until(driverHandler.ExpectedConditions.elementToBeClickable(sleepSynchronizer.By.id('details-button')));

//Handling Cookies
var sessionCOOKIES = WDS.browser.manage().getCookies();
WDS.vars.putObject('cookies', sessionCOOKIES)
java.lang.Thread.sleep(6000);

报错详情 #

Chrome Driver报错

2024-01-13 19:55:24,522 ERROR o.a.j.JMeter: Uncaught exception in thread Thread[Thread Group 1-1,6,main]
java.lang.NoClassDefFoundError: Could not initialize class org.openqa.selenium.remote.http.netty.NettyClient
    at org.openqa.selenium.remote.http.netty.NettyClient$Factory.createClient(NettyClient.java:124) ~[selenium-remote-driver-4.13.0.jar:?]
    at org.openqa.selenium.remote.HttpCommandExecutor.<init>(HttpCommandExecutor.java:115) ~[selenium-remote-driver-4.13.0.jar:?]
    at org.openqa.selenium.remote.HttpCommandExecutor.<init>(HttpCommandExecutor.java:92) ~[selenium-remote-driver-4.13.0.jar:?]
    at org.openqa.selenium.remote.service.DriverCommandExecutor.<init>(DriverCommandExecutor.java:89) ~[selenium-remote-driver-4.13.0.jar:?]
    at org.openqa.selenium.chromium.ChromiumDriverCommandExecutor.<init>(ChromiumDriverCommandExecutor.java:43) ~[selenium-chromium-driver-4.13.0.jar:?]

Gecko Driver报错

2024-01-13 19:37:27,069 ERROR o.a.j.JMeter: Uncaught exception in thread Thread[Thread Group 1-1,6,main]
java.lang.NoClassDefFoundError: Could not initialize class org.openqa.selenium.remote.http.netty.NettyClient
    at org.openqa.selenium.remote.http.netty.NettyClient$Factory.createClient(NettyClient.java:124) ~[selenium-remote-driver-4.13.0.jar:?]
    at org.openqa.selenium.remote.HttpCommandExecutor.<init>(HttpCommandExecutor.java:115) ~[selenium-remote-driver-4.13.0.jar:?]
    at org.openqa.selenium.remote.HttpCommandExecutor.<init>(HttpCommandExecutor.java:92) ~[selenium-remote-driver-4.13.0.jar:?]
    at org.openqa.selenium.remote.service.DriverCommandExecutor.<init>(DriverCommandExecutor.java:89) ~[selenium-remote-driver-4.13.0.jar:?]
    at org.openqa.selenium.firefox.FirefoxDriver$FirefoxDriverCommandExecutor.<init>(FirefoxDriver.java:415) ~[selenium-firefox-driver-4.13.0.jar:?]
    at org.openqa.selenium.firefox.FirefoxDriver.generateExecutor(FirefoxDriver.java:147) ~[selenium-firefox-driver-4.13.0.jar:?]
    at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:132) ~[selenium-firefox-driver-4.13.0.jar:?]

Chromium Driver报错

注意：Chromium浏览器可启动，但出现以下报错

2024-01-13 19:38:16,709 ERROR o.a.j.t.JMeterThread: Error calling threadStarted
org.openqa.selenium.WebDriverException: Timed out waiting for driver server to start.
Build info: version: '4.13.0', revision: 'ba948ece5b*'
System info: os.name: 'Windows 10', os.arch: 'amd64', os.version: '10.0', java.version: '17.0.6'
Driver info: driver.version: unknown
    at org.openqa.selenium.remote.service.DriverService.start(DriverService.java:248) ~[selenium-remote-driver-4.13.0.jar:?]
    at com.googlecode.jmeter.plugins.webdriver.config.ChromeDriverConfig.getThreadService(ChromeDriverConfig.java:47) ~[jmeter-plugins-webdriver-4.13.0.0.jar:?]
    at com.googlecode.jmeter.plugins.webdriver.config.ChromeDriverConfig.createBrowser(ChromeDriverConfig.java:26) ~[jmeter-plugins-webdriver-4.13.0.0.jar:?]
    at com.googlecode.jmeter.plugins.webdriver.config.ChromeDriverConfig.createBrowser(ChromeDriverConfig.java:14) ~[jmeter-plugins-webdriver-4.13.0.0.jar:?]
    at com.googlecode.jmeter.plugins.webdriver.config.WebDriverConfig.getPreparedBrowser(WebDriverConfig.java:221) ~[jmeter-plugins-webdriver-4.13.0.0.jar:?]
    at com.googlecode.jmeter.plugins.webdriver.config.WebDriverConfig.threadStarted(WebDriverConfig.java:152) ~[jmeter-plugins-webdriver-4.13.0.0.jar:?]
    at org.apache.jmeter.threads.JMeterThread$ThreadListenerTraverser.addNode(JMeterThread.java:769) [ApacheJMeter_core.jar:5.3]

解决方案 #

1. 补全Netty相关依赖包 #

NoClassDefFoundError核心原因是缺少Selenium 4.x依赖的Netty组件，需确保以下Jar包存在于JMeter的lib/ext目录：

• netty-buffer-*.jar
• netty-codec-*.jar
• netty-codec-http-*.jar
• netty-codec-http2-*.jar
• netty-common-*.jar
• netty-handler-*.jar
• netty-resolver-*.jar
• netty-transport-*.jar

若通过JMeter插件管理器安装WebDriver Sampler，可重新安装插件，自动补全所有依赖。

2. 匹配版本兼容性 #

JMeter 5.3官方推荐Java版本为8-11，Java 17兼容性有限，建议降级至Java 11 LTS。同时确认WebDriver Sampler插件版本与Selenium版本严格匹配（当前WebDriver 4.13.0对应插件版本4.13.0.0，检查lib/ext目录下jmeter-plugins-webdriver-4.13.0.0.jar是否存在）。

3. 检查Driver配置与权限 #

• 在WebDriver Config元件中，确保Driver路径指向正确的可执行文件（如chromedriver.exe）；
• Linux/Mac系统需给Driver文件添加可执行权限：chmod +x chromedriver；
• 关闭浏览器自动更新，避免浏览器版本与Driver版本不匹配。

4. 延长Driver启动超时 #

针对Chromium的超时问题，在WebDriver Config元件中找到“Timeout”设置，将启动超时时间从默认值延长至60秒以上，避免系统资源不足导致启动失败。

5. 切换脚本语言为Groovy #

BeanShell兼容性差、性能弱，建议替换为Groovy脚本，示例如下：

import org.openqa.selenium.support.ui.WebDriverWait
import org.openqa.selenium.support.ui.ExpectedConditions

def wait = new WebDriverWait(WDS.browser, 5)

WDS.sampleResult.sampleStart()
WDS.browser.get('<application URL>')
wait.until(ExpectedConditions.elementToBeClickable(wait.by.id('details-button')))

def cookies = WDS.browser.manage().getCookies()
WDS.vars.putObject('cookies', cookies)
Thread.sleep(6000)

WDS.sampleResult.sampleEnd()

6. 清理JMeter缓存 #

删除JMeterbin/cache目录下的所有文件，重启JMeter，避免旧缓存导致类加载冲突。

内容的提问来源于stack exchange，提问作者Jyoti Prakash Mallick