How to use Logic Controller in JMeter when I want to execute one application 'n' number of times

Question

I have one API, who gives a dynamic response in terms of number arrays. I want to execute next API based on the count that I got in the first API.

API 1 Response:
{ 
  "Test 1": [
{Array 1},
{Array 2},
{Array 3}   ]
}

API 2 Request:
{Array 1},
{Array 2},
{Array 3} 

I tried If controller but my API exectuing one time only though i have 3 array.

Answer 1

Assuming you have the following JSON:

{
  "Test 1": [
    {
      "foo": 1
    },
    {
      "bar": 2
    },
    {
      "baz": 3
    }
  ]
}

1. Add JSR223 PostProcessor as a child of the request which produces the above JSON and put the following code into "Script" area:

def json = new groovy.json.JsonSlurper().parse(prev.getResponseData())
def array = json.get('Test 1')
array.eachWithIndex { item, index, jmeterindex = index + 1 ->    
    vars.put('array_' + jmeterindex,new groovy.json.JsonOutput().toJson(item))
}

2. Add ForEach Controller to your Test Plan (somewhere after the main request) and configure it as follows:

   • Input variable prefix: array
   • Output variable name: current_array
3. Add HTTP Request sampler as a child of the ForEach Controller. You should be able to refer the array value as ${current_array} where required

Demo:

References:

• Groovy: Parsing and producing JSON
• Apache Groovy - Why and How You Should Use It

Example test plan:

<?xml version="1.0" encoding="UTF-8"?>
<jmeterTestPlan version="1.2" properties="3.2" jmeter="3.2 r1790748">
    <hashTree>
        <TestPlan guiclass="TestPlanGui" testclass="TestPlan" testname="Test Plan" enabled="true">
            <stringProp name="TestPlan.comments"></stringProp>
            <boolProp name="TestPlan.functional_mode">false</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="Thread Group" 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">1</stringProp>
                </elementProp>
                <stringProp name="ThreadGroup.num_threads">1</stringProp>
                <stringProp name="ThreadGroup.ramp_time">1</stringProp>
                <longProp name="ThreadGroup.start_time">1503209281000</longProp>
                <longProp name="ThreadGroup.end_time">1503209281000</longProp>
                <boolProp name="ThreadGroup.scheduler">false</boolProp>
                <stringProp name="ThreadGroup.duration"></stringProp>
                <stringProp name="ThreadGroup.delay"></stringProp>
            </ThreadGroup>
            <hashTree>
                <JSR223Sampler guiclass="TestBeanGUI" testclass="JSR223Sampler" testname="Produce JSON" enabled="true">
                    <stringProp name="scriptLanguage">groovy</stringProp>
                    <stringProp name="parameters"></stringProp>
                    <stringProp name="filename"></stringProp>
                    <stringProp name="cacheKey"></stringProp>
                    <stringProp name="script">return &quot;{\n&quot; +
                        &quot;  \&quot;Test 1\&quot;: [\n&quot; +
                        &quot;    {\n&quot; +
                        &quot;      \&quot;foo\&quot;: 1\n&quot; +
                        &quot;    },\n&quot; +
                        &quot;    {\n&quot; +
                        &quot;      \&quot;bar\&quot;: 2\n&quot; +
                        &quot;    },\n&quot; +
                        &quot;    {\n&quot; +
                        &quot;      \&quot;baz\&quot;: 3\n&quot; +
                        &quot;    }\n&quot; +
                        &quot;  ]\n&quot; +
                        &quot;}&quot;</stringProp>
                </JSR223Sampler>
                <hashTree>
                    <JSR223PostProcessor guiclass="TestBeanGUI" testclass="JSR223PostProcessor" testname="JSR223 PostProcessor" enabled="true">
                        <stringProp name="scriptLanguage">groovy</stringProp>
                        <stringProp name="parameters"></stringProp>
                        <stringProp name="filename"></stringProp>
                        <stringProp name="cacheKey"></stringProp>
                        <stringProp name="script">def json = new groovy.json.JsonSlurper().parse(prev.getResponseData())
                            def array = json.get(&apos;Test 1&apos;)
                            array.eachWithIndex { item, index, jmeterindex = index + 1 -&gt;
                            vars.put(&apos;array_&apos; + jmeterindex,new groovy.json.JsonOutput().toJson(item))
                            }</stringProp>
                    </JSR223PostProcessor>
                    <hashTree/>
                </hashTree>
                <ForeachController guiclass="ForeachControlPanel" testclass="ForeachController" testname="ForEach Controller" enabled="true">
                    <stringProp name="ForeachController.inputVal">array</stringProp>
                    <stringProp name="ForeachController.returnVal">current_array</stringProp>
                    <boolProp name="ForeachController.useSeparator">true</boolProp>
                </ForeachController>
                <hashTree>
                    <JSR223Sampler guiclass="TestBeanGUI" testclass="JSR223Sampler" testname="${current_array}" enabled="true">
                        <stringProp name="scriptLanguage">groovy</stringProp>
                        <stringProp name="parameters"></stringProp>
                        <stringProp name="filename"></stringProp>
                        <stringProp name="cacheKey"></stringProp>
                        <stringProp name="script">log.info(vars.get(&apos;current_array&apos;))</stringProp>
                    </JSR223Sampler>
                    <hashTree/>
                </hashTree>
                <ResultCollector guiclass="ViewResultsFullVisualizer" testclass="ResultCollector" testname="View Results Tree" enabled="true">
                    <boolProp name="ResultCollector.error_logging">false</boolProp>
                    <objProp>
                        <name>saveConfig</name>
                        <value class="SampleSaveConfiguration">
                            <time>true</time>
                            <latency>true</latency>
                            <timestamp>true</timestamp>
                            <success>true</success>
                            <label>true</label>
                            <code>true</code>
                            <message>true</message>
                            <threadName>true</threadName>
                            <dataType>true</dataType>
                            <encoding>false</encoding>
                            <assertions>true</assertions>
                            <subresults>true</subresults>
                            <responseData>false</responseData>
                            <samplerData>false</samplerData>
                            <xml>false</xml>
                            <fieldNames>true</fieldNames>
                            <responseHeaders>false</responseHeaders>
                            <requestHeaders>false</requestHeaders>
                            <responseDataOnError>false</responseDataOnError>
                            <saveAssertionResultsFailureMessage>true</saveAssertionResultsFailureMessage>
                            <assertionsResultsToSave>0</assertionsResultsToSave>
                            <bytes>true</bytes>
                            <sentBytes>true</sentBytes>
                            <threadCounts>true</threadCounts>
                            <idleTime>true</idleTime>
                            <connectTime>true</connectTime>
                        </value>
                    </objProp>
                    <stringProp name="filename"></stringProp>
                </ResultCollector>
                <hashTree/>
            </hashTree>
        </hashTree>
        <WorkBench guiclass="WorkBenchGui" testclass="WorkBench" testname="WorkBench" enabled="true">
            <boolProp name="WorkBench.save">true</boolProp>
        </WorkBench>
        <hashTree/>
    </hashTree>
</jmeterTestPlan>