JAVA 代码调用Jmeter (动态配置请求参数)

一、Jmeter如何进行动态设置请求参数

• Jmeter使用占位符的方式进行动态替换请求参数内容。

        HTTPSamplerProxy httpSamplerProxy = new HTTPSamplerProxy();
        httpSamplerProxy.addArgument("data", "${data}");

• 那么替换占位符的数据是存放在哪里呢？答案就是替换的数据存放在每个线程的Context中。

当Jmeter创建每个Thread的时候都会创建一个Context，而Thread的Context我们可以通过JMeterContextService的getContext方法获取当前的线程的Context.

二、实现动态配置请求参数方式

CSV

Jmeter在图形化界面提供了CSV的方式进行动态配置请求参数。在Java代码中也可以通过CSV方式来进行实现，但是这种方式存在弊端，因为使用CSV是假设数据全部确定的情况下使用，如果我们所需要的请求参数的数据是不确定况下，我们就不可以使用CSV的方式进行处理。

Monitor

我们可以通过JMeterThread.java类发现,每个Sample都会调用SampleMonitor进行监视每个Sample,那么我们可以通过SampleMonitor来进行动态设置请求的参数。

JMeterThread.java
      if (running) {
            Sampler sampler = pack.getSampler();
            sampler.setThreadContext(threadContext);
            // TODO should this set the thread names for all the subsamples?
            // might be more efficient than fetching the name elsewhere
            sampler.setThreadName(threadName);
            TestBeanHelper.prepare(sampler);

            // Perform the actual sample
            currentSampler = sampler;
            if (!sampleMonitors.isEmpty()) {
                for (SampleMonitor sampleMonitor : sampleMonitors) {
                    sampleMonitor.sampleStarting(sampler);
                }
            }
            try {
                result = sampler.sample(null);
            } finally {
                if (!sampleMonitors.isEmpty()) {
                    for (SampleMonitor sampleMonitor : sampleMonitors) {
                        sampleMonitor.sampleEnded(sampler);
                    }
                }
            }
            currentSampler = null;
        }

三、时序图

image.png

三、代码实现

1. TestPlanLauncher.java

public class TestPlanLauncher {

    public static void main(String[] args) {
        // jemter 引擎
        StandardJMeterEngine standardJMeterEngine = new StandardJMeterEngine();
        // 设置不适用gui的方式调用jmeter
        System.setProperty(JMeter.JMETER_NON_GUI, "true");
        // 设置jmeter.properties文件，我们将jmeter文件存放在resources中，通过classload
        String path = TestPlanLauncher.class.getClassLoader().getResource("jmeter.properties").getPath();
        File jmeterPropertiesFile = new File(path);
        if (jmeterPropertiesFile.exists()) {
            JMeterUtils.loadJMeterProperties(jmeterPropertiesFile.getPath());
            HashTree testPlanTree = new HashTree();
            // 创建测试计划
            TestPlan testPlan = new TestPlan("Create JMeter Script From Java Code");
            String variableNames = "data";
            // 创建http请求收集器
            HTTPSamplerProxy examplecomSampler = createHTTPSamplerProxy(variableNames);
            // 创建循环控制器
            LoopController loopController = createLoopController();
            // 创建线程组
            ThreadGroup threadGroup = createThreadGroup();
            // 线程组设置循环控制
            threadGroup.setSamplerController(loopController);
            // 将测试计划添加到测试配置树种
            HashTree threadGroupHashTree = testPlanTree.add(testPlan, threadGroup);
            // 将http请求采样器添加到线程组下
            threadGroupHashTree.add(examplecomSampler);
            //增加监视器
            threadGroupHashTree.add(createHttpSampleMonitor(variableNames));
            //增加结果收集
            Summariser summer = null;
            String summariserName = JMeterUtils.getPropDefault("summariser.name", "summary");
            if (summariserName.length() > 0) {
                summer = new Summariser(summariserName);
            }
            ResultCollector logger = new ResultCollector(summer);
            testPlanTree.add(testPlanTree.getArray(), logger);
            // 配置jmeter
            standardJMeterEngine.configure(testPlanTree);
            // 运行
            standardJMeterEngine.run();
        }
    }

    /**
     * 创建线程组
     * 
     * @return
     */
    public static ThreadGroup createThreadGroup() {
        ThreadGroup threadGroup = new ThreadGroup();
        threadGroup.setName("Example Thread Group");
        threadGroup.setNumThreads(1);
        threadGroup.setRampUp(0);
        threadGroup.setProperty(TestElement.TEST_CLASS, ThreadGroup.class.getName());
        threadGroup.setScheduler(true);
        threadGroup.setDuration(60);
        threadGroup.setDelay(0);
        return threadGroup;
    }

    /**
     * 创建循环控制器
     * 
     * @return
     */
    public static LoopController createLoopController() {
        // Loop Controller
        LoopController loopController = new LoopController();
        loopController.setLoops(-1);
        loopController.setContinueForever(true);
        loopController.setProperty(TestElement.TEST_CLASS, LoopController.class.getName());
        loopController.initialize();
        return loopController;
    }

    /**
     * 增加监视器
     * @param variableNames
     * @return
     */
    public static HttpSampleMonitor createHttpSampleMonitor(String variableNames){
        HttpSampleMonitor httpSampleMonitor = new HttpSampleMonitor();
        if (StringUtils.isNoneBlank(variableNames)) {
            httpSampleMonitor.setProperty("variableNames",variableNames);
        }
        return httpSampleMonitor;
    }
    /**
     * 创建http采样器
     * 
     * @return
     */
    public static HTTPSamplerProxy createHTTPSamplerProxy(String variableNames) {
        HTTPSamplerProxy httpSamplerProxy = new HTTPSamplerProxy();
        httpSamplerProxy.addArgument(variableNames, "${"+variableNames+"}");
        httpSamplerProxy.setDomain("www.baidu.com");
        httpSamplerProxy.setPort(80);
        httpSamplerProxy.setPath("/");
        httpSamplerProxy.setMethod("GET");
        httpSamplerProxy.setConnectTimeout("5000");
        httpSamplerProxy.setUseKeepAlive(true);
        httpSamplerProxy.setProperty(TestElement.TEST_CLASS, HTTPSamplerProxy.class.getName());
        return httpSamplerProxy;
    }
}

2.HttpSampleMonitor

public class HttpSampleMonitor extends ConfigTestElement implements SampleMonitor {
    private static final Logger log = LoggerFactory.getLogger(HttpSampleMonitor.class);

    private static final long serialVersionUID = 23221L;

    // 请求变量名以逗号分隔
    private String variableNames;
    // 分隔后的变量名
    private String[] vars;
    @Override
    public void sampleStarting(Sampler sampler) {
        final JMeterContext context = getThreadContext();
        JMeterVariables threadVars = context.getVariables();
        if (StringUtils.isNoneEmpty(getVariableNames())) {
            vars = JOrphanUtils.split(getVariableNames(), ",");
            trimVarNames(vars);
            for (int i = 0; i < vars.length; i++) {
                threadVars.put(vars[i], i + "");
            }
        }
    }

    @Override
    public void sampleEnded(Sampler sampler) {

    }

    /**
     * trim content of array varNames
     * 
     * @param varsNames
     */
    private void trimVarNames(String[] varsNames) {
        for (int i = 0; i < varsNames.length; i++) {
            varsNames[i] = varsNames[i].trim();
        }
    }
    public String getVariableNames() {
        this.variableNames = this.getPropertyAsString("variableNames");
        return variableNames;
    }

}

3.特别说明

• 在HTTPSamplerProxy中的addArgument方法设置的占位符需要使用${}的形式。并且要与HttpSampleMonitor中threadVars对象put的name保持一致。
• HttpSampleMonitor：我们的HttpSampleMonitor是为每一个线程增加一个HttpSampleMonitor，所以Jmeter需要对HttpSampleMonitor进行对象的clone和对clone的对象设置Property. 我们可以通过继承ConfigTestElement来获取对象拷贝和Property设置的能力。

Reference：
https://jmeter.apache.org/api/index.html