How to create and run Apache JMeter Test Scripts from a Java program and capture output?

Question

I am new to jmeter API world. I am working on creating a java based jmeter test by using APIs. I followed the thread: How to create and run Apache JMeter Test Scripts from a Java program? to get a request running.

Now, I need to parse the output. I was looking to use JSONPostProcessor class. Any suggestions on how to wire this would be greatly appreciated.

code looks something like:

import org.apache.jmeter.control.LoopController;
import org.apache.jmeter.engine.StandardJMeterEngine;
import org.apache.jmeter.protocol.http.sampler.HTTPSampler;
import org.apache.jmeter.testelement.TestElement;
import org.apache.jmeter.testelement.TestPlan;
import org.apache.jmeter.threads.SetupThreadGroup;
import org.apache.jmeter.util.JMeterUtils;
import org.apache.jorphan.collections.HashTree;

public class JMeterTestFromCode {

    public static void main(String[] args){
        // Engine
        StandardJMeterEngine jm = new StandardJMeterEngine();
        // jmeter.properties
        JMeterUtils.loadJMeterProperties("c:/tmp/jmeter.properties");

        HashTree hashTree = new HashTree();     

        // HTTP Sampler
        HTTPSampler httpSampler = new HTTPSampler();
        httpSampler.setDomain("www.google.com");
        httpSampler.setPort(80);
        httpSampler.setPath("/");
        httpSampler.setMethod("GET");

        // Loop Controller
        TestElement loopCtrl = new LoopController();
        ((LoopController)loopCtrl).setLoops(1);
        ((LoopController)loopCtrl).addTestElement(httpSampler);
        ((LoopController)loopCtrl).setFirst(true);

        // Thread Group
        SetupThreadGroup threadGroup = new SetupThreadGroup();
        threadGroup.setNumThreads(1);
        threadGroup.setRampUp(1);
        threadGroup.setSamplerController((LoopController)loopCtrl);

        // Test plan
        TestPlan testPlan = new TestPlan("MY TEST PLAN");

        hashTree.add("testPlan", testPlan);
        hashTree.add("loopCtrl", loopCtrl);
        hashTree.add("threadGroup", threadGroup);
        hashTree.add("httpSampler", httpSampler);       

        jm.configure(hashTree);

        jm.run();

        //NEED HELP ON HOW TO GET RESPONSE FROM THE EXECUTED REQUEST     
    }
}

Thanks Sunil

Post relevant code and ask questions based on that. – Xpleria Jul 23 '18 at 20:24 — Xpleria, Jul 23 '18 at 20:24
Updated code - any help is appreciated – Sunil B Jul 24 '18 at 01:02 — Sunil B, Jul 24 '18 at 01:02

score 1 · Accepted Answer · answered Jul 24 '18 at 04:34

The code to add JSON Extractor is pretty much similar to the other Test Elements

JSONPostProcessor jsonExtractor = new JSONPostProcessor();
jsonExtractor.setName("JSON Extractor");
jsonExtractor.setRefNames("foo");
jsonExtractor.setJsonPathExpressions("$.title");
jsonExtractor.setProperty(TestElement.TEST_CLASS, JSONPostProcessor.class.getName());
jsonExtractor.setProperty(TestElement.GUI_CLASS, JSONPostProcessorGui.class.getName());

I would recommend setting TestElement.TEST_CLASS and TestElement.GUI_CLASS properties as this way you will be able to open generated .jmx file in JMeter GUI which is extra useful for debugging purposes and sharing the script with colleagues.

Full code just in case:

import org.apache.jmeter.config.Arguments;
import org.apache.jmeter.config.gui.ArgumentsPanel;
import org.apache.jmeter.control.LoopController;
import org.apache.jmeter.control.gui.LoopControlPanel;
import org.apache.jmeter.control.gui.TestPlanGui;
import org.apache.jmeter.engine.StandardJMeterEngine;
import org.apache.jmeter.extractor.json.jsonpath.JSONPostProcessor;
import org.apache.jmeter.extractor.json.jsonpath.gui.JSONPostProcessorGui;
import org.apache.jmeter.protocol.http.control.gui.HttpTestSampleGui;
import org.apache.jmeter.protocol.http.sampler.HTTPSamplerProxy;
import org.apache.jmeter.reporters.ResultCollector;
import org.apache.jmeter.reporters.Summariser;
import org.apache.jmeter.save.SaveService;
import org.apache.jmeter.testelement.TestElement;
import org.apache.jmeter.testelement.TestPlan;
import org.apache.jmeter.threads.ThreadGroup;
import org.apache.jmeter.threads.gui.ThreadGroupGui;
import org.apache.jmeter.util.JMeterUtils;
import org.apache.jorphan.collections.HashTree;

import java.io.FileOutputStream;

public class JMeterFromJava {

    public static void main(String[] args) throws Exception {

        StandardJMeterEngine jm = new StandardJMeterEngine();

        String jmeterHome = "/path/to/your/JMeter/installation";


        JMeterUtils.setJMeterHome(jmeterHome);
        JMeterUtils.loadJMeterProperties(jmeterHome + "/bin/jmeter.properties");
        JMeterUtils.initLocale();


        HashTree testPlanTree = new HashTree();


        HTTPSamplerProxy jsonPlaceHolderSampler = new HTTPSamplerProxy();
        jsonPlaceHolderSampler.setDomain("https://jsonplaceholder.typicode.com/posts/1");
        jsonPlaceHolderSampler.setPort(80);
        jsonPlaceHolderSampler.setPath("/");
        jsonPlaceHolderSampler.setMethod("GET");
        jsonPlaceHolderSampler.setName("HTTP Request");
        jsonPlaceHolderSampler.setProperty(TestElement.TEST_CLASS, HTTPSamplerProxy.class.getName());
        jsonPlaceHolderSampler.setProperty(TestElement.GUI_CLASS, HttpTestSampleGui.class.getName());

        JSONPostProcessor jsonExtractor = new JSONPostProcessor();
        jsonExtractor.setName("JSON Extractor");
        jsonExtractor.setRefNames("foo");
        jsonExtractor.setJsonPathExpressions("$.title");
        jsonExtractor.setProperty(TestElement.TEST_CLASS, JSONPostProcessor.class.getName());
        jsonExtractor.setProperty(TestElement.GUI_CLASS, JSONPostProcessorGui.class.getName());


        LoopController loopController = new LoopController();
        loopController.setLoops(1);
        loopController.setFirst(true);
        loopController.setProperty(TestElement.TEST_CLASS, LoopController.class.getName());
        loopController.setProperty(TestElement.GUI_CLASS, LoopControlPanel.class.getName());
        loopController.initialize();

        ThreadGroup threadGroup = new ThreadGroup();
        threadGroup.setName("Example Thread Group");
        threadGroup.setNumThreads(1);
        threadGroup.setRampUp(1);
        threadGroup.setSamplerController(loopController);
        threadGroup.setProperty(TestElement.TEST_CLASS, ThreadGroup.class.getName());
        threadGroup.setProperty(TestElement.GUI_CLASS, ThreadGroupGui.class.getName());

        TestPlan testPlan = new TestPlan("Create JMeter Script From Java Code");
        testPlan.setProperty(TestElement.TEST_CLASS, TestPlan.class.getName());
        testPlan.setProperty(TestElement.GUI_CLASS, TestPlanGui.class.getName());
        testPlan.setUserDefinedVariables((Arguments) new ArgumentsPanel().createTestElement());

        HashTree blazeMeterSamplerTree = new HashTree();
        blazeMeterSamplerTree.add(jsonPlaceHolderSampler, jsonExtractor);


        testPlanTree.add(testPlan);
        HashTree threadGroupHashTree = testPlanTree.add(testPlan, threadGroup);
        threadGroupHashTree.add(blazeMeterSamplerTree);

        SaveService.saveTree(testPlanTree, new FileOutputStream(jmeterHome + "/bin/test.jmx"));

        Summariser summer = null;
        String summariserName = JMeterUtils.getPropDefault("summariser.name", "summary");
        if (summariserName.length() > 0) {
            summer = new Summariser(summariserName);
        }

        String logFile = jmeterHome + "/bin/test.jtl";
        ResultCollector logger = new ResultCollector(summer);
        logger.setFilename(logFile);
        testPlanTree.add(testPlanTree.getArray()[0], logger);

        jm.configure(testPlanTree);

        jm.run();
    }
}

More information: Five Ways To Launch a JMeter Test without Using the JMeter GUI

Thanks @Dmitri T. This is very helpful. Quick follow-up question --Once the JSONPostProcessor runs, how do you extract the results - especially if there are multiple runs? Let me know. Thanks. Sunil — Sunil B, Jul 25 '18 at 17:58

How to create and run Apache JMeter Test Scripts from a Java program and capture output?

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