How to Create and Run Apache Jmeter Test Scripts from a Java Program

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

If I understand correctly, you want to run an entire test plan programmatically from within a Java program. Personally, I find it easier to create a test plan .JMX file and run it in JMeter non-GUI mode :)

Here is a simple Java example based on the controller and sampler used in the original question.

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();
    }
}

Dependencies

These are the bare mininum JARs required based on JMeter 2.9 and the HTTPSampler used.
Other samplers will most likely have different library JAR dependencies.

ApacheJMeter_core.jar
jorphan.jar
avalon-framework-4.1.4.jar
ApacheJMeter_http.jar
commons-logging-1.1.1.jar
logkit-2.0.jar
oro-2.0.8.jar
commons-io-2.2.jar
commons-lang3-3.1.jar

Note

I also hardwired the path to jmeter.properties in c:\tmp on Windows after first copying it from the JMeter installation /bin directory.
I wasn't sure how to set a forward proxy for the HTTPSampler.

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

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

Creating a New JMeter Test Purely in Java ans save as valid *.jmx

Most likely you forgot to set the following properties:

TestElement.TEST_CLASS
TestElement.GUI_CLASS

If you omit them you will still be able to run the test using JMeterEngine, however attempt to open the generated script in GUI will fail.

Here is an example Test Plan which contains a Thread Group and a HTTP Request sampler, you can use it as a reference.

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.protocol.http.control.gui.HttpTestSampleGui;
import org.apache.jmeter.protocol.http.sampler.HTTPSamplerProxy;
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.File;
import java.io.FileOutputStream;

public class JMeterFromJava {

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

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

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

        HashTree testPlanTree = new HashTree();

        HTTPSamplerProxy examplecomSampler = new HTTPSamplerProxy();
        examplecomSampler.setDomain("example.com");
        examplecomSampler.setPort(80);
        examplecomSampler.setPath("/");
        examplecomSampler.setMethod("GET");
        examplecomSampler.setName("Open example.com");
        examplecomSampler.setProperty(TestElement.TEST_CLASS, HTTPSamplerProxy.class.getName());
        examplecomSampler.setProperty(TestElement.GUI_CLASS, HttpTestSampleGui.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());

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

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

    }
}

References:

Five Ways To Launch a JMeter Test without Using the JMeter GUI
jmeter-from-code

How to programmatically run a jMeter benchmark from code?

You can either kick off an existing JMeter test or create a new one using JMeter API

Run existing test example code:

import org.apache.jmeter.engine.StandardJMeterEngine;
import org.apache.jmeter.reporters.ResultCollector;
import org.apache.jmeter.reporters.Summariser;
import org.apache.jmeter.save.SaveService;
import org.apache.jmeter.util.JMeterUtils;
import org.apache.jorphan.collections.HashTree;

import java.io.File;

public class RunExistingJMeterTest {

    public static void main(String[] args) throws Exception {
        // Initialize properties
        JMeterUtils.loadJMeterProperties("/path/to/your/jmeter/bin/jmeter.properties");        

        // JMeter Engine
        StandardJMeterEngine jmeter = new StandardJMeterEngine();

        // Initialize logging, locale, etc.
        JMeterUtils.setJMeterHome("/path/to/your/jmeter");
        JMeterUtils.initLocale();

        // Initialize JMeter SaveService
        SaveService.loadProperties();

        // Load existing .jmx Test Plan
        HashTree testPlanTree = SaveService.loadTree(new File("/path/to/your/jmeter/extras/Test.jmx"));

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

        // Store execution results into a .jtl file
        String logFile = "/path/to/results/file.jtl";
        ResultCollector logger = new ResultCollector(summer);
        logger.setFilename(logFile);
        testPlanTree.add(testPlanTree.getArray()[0], logger);

        // Run JMeter Test
        jmeter.configure(testPlanTree);
        jmeter.run();

    }
}

Create JMeter script programmatically:

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.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 CreateNewJMeterTest {

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

        StandardJMeterEngine jmeter = new StandardJMeterEngine();

        //JMeter initialization (properties, log levels, locale, etc)
        JMeterUtils.setJMeterHome("/path/to/your/jmeter/installation");
        JMeterUtils.loadJMeterProperties("/path/to/your/jmeter/bin/jmeter.properties");
        JMeterUtils.initLocale();

        // JMeter Test Plan, basically JOrphan HashTree
        HashTree testPlanTree = new HashTree();

        // First HTTP Sampler - open example.com
        HTTPSamplerProxy examplecomSampler = new HTTPSamplerProxy();
        examplecomSampler.setDomain("example.com");
        examplecomSampler.setPort(80);
        examplecomSampler.setPath("/");
        examplecomSampler.setMethod("GET");
        examplecomSampler.setName("Open example.com");
        examplecomSampler.setProperty(TestElement.TEST_CLASS, HTTPSamplerProxy.class.getName());
        examplecomSampler.setProperty(TestElement.GUI_CLASS, HttpTestSampleGui.class.getName());

        // Loop Controller
        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();

        // Thread Group
        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());

        // Test Plan
        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());

        // Construct Test Plan from previously initialized elements
        testPlanTree.add(testPlan);
        HashTree threadGroupHashTree = testPlanTree.add(testPlan, threadGroup);
        threadGroupHashTree.add(examplecomSampler);

        // save generated test plan to JMeter's .jmx file format
        SaveService.saveTree(testPlanTree, new FileOutputStream("/path/to/test.jmx"));

        //add Summarizer output to get test progress in stdout like:
        // summary =      2 in   1.3s =    1.5/s Avg:   631 Min:   290 Max:   973 Err:     0 (0.00%)
        Summariser summer = null;
        String summariserName = JMeterUtils.getPropDefault("summariser.name", "summary");
        if (summariserName.length() > 0) {
            summer = new Summariser(summariserName);
        }

        // Store execution results into a .jtl file
        String logFile = "/path/to/test/results.jtl";
        ResultCollector logger = new ResultCollector(summer);
        logger.setFilename(logFile);
        testPlanTree.add(testPlanTree.getArray()[0], logger);

        // Run Test Plan
        jmeter.configure(testPlanTree);
        jmeter.run();

        System.exit(0);
    }
}

Check out Five Ways To Launch a JMeter Test without Using the JMeter GUI article for more information.

Creating a New JMeter Test Purely in Java for Java Sampler

Example code to add a Java Request sampler which will execute SleepTest will look like:

JavaSampler javaSampler = new JavaSampler();
javaSampler.setName("Java Request");
javaSampler.setClassname("org.apache.jmeter.protocol.java.test.SleepTest");
Arguments arguments = new Arguments();
arguments.addArgument("SleepTime", "1000");
arguments.addArgument("SleepMask", "0x33F");
javaSampler.setArguments(arguments);
javaSampler.setProperty(TestElement.TEST_CLASS, JavaSampler.class.getName());
javaSampler.setProperty(TestElement.GUI_CLASS, JavaTestSamplerGui.class.getName());

In case if you need execute your own class implementing JavaSamplerClient interface just substitute the classname and provide your own arguments if needed.