JMeter example source code file (IfController.java)

This example JMeter source code file (IfController.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - JMeter tags/keywords

condition, condition, context, exception, ifcontroller, ifcontroller, io, non-nls-1, non-nls-1, object, override, scriptable, string, string, stringproperty

The JMeter IfController.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.apache.jmeter.control;

import java.io.Serializable;

import org.apache.jmeter.samplers.Sampler;
import org.apache.jmeter.testelement.property.StringProperty;
import org.apache.jorphan.logging.LoggingManager;
import org.apache.log.Logger;
import org.mozilla.javascript.Context;
import org.mozilla.javascript.Scriptable;

/*******************************************************************************
 *
 *
 * This is a Conditional Controller; it will execute the set of statements
 * (samplers/controllers, etc) while the 'condition' is true.
 * In a programming world - this is equivalant of :
 * if (condition) {
 *          statements ....
 *          }
 * In JMeter you may have : Thread-Group (set to loop a number of times or indefinitely,
 *    ... Samplers ... (e.g. Counter )
 *    ... Other Controllers ....
 *    ... IfController ( condition set to something like - ${counter}<10)
 *       ... statements to perform if condition is true
 *       ...
 *    ... Other Controllers /Samplers }
 *
 ******************************************************************************/

// for unit test code @see TestIfController

public class IfController extends GenericController implements Serializable {

    private static final Logger logger = LoggingManager.getLoggerForClass();

    private static final long serialVersionUID = 240L;

    private final static String CONDITION = "IfController.condition"; //$NON-NLS-1$

    private final static String EVALUATE_ALL = "IfController.evaluateAll"; //$NON-NLS-1$

    private static final String USE_EXPRESSION = "IfController.useExpression"; //$NON-NLS-1$

    /**
     * constructor
     */
    public IfController() {
        super();
    }

    /**
     * constructor
     */
    public IfController(String condition) {
        super();
        this.setCondition(condition);
    }

    /**
     * Condition Accessor - this is gonna be like ${count}<10
     */
    public void setCondition(String condition) {
        setProperty(new StringProperty(CONDITION, condition));
    }

    /**
     * Condition Accessor - this is gonna be like ${count}<10
     */
    public String getCondition() {
        return getPropertyAsString(CONDITION);
    }

    /**
     * evaluate the condition clause log error if bad condition
     */
    private static boolean evaluateCondition(String cond) {
        logger.debug("    getCondition() : [" + cond + "]");

        String resultStr = "";
        boolean result = false;

        // now evaluate the condition using JavaScript
        Context cx = Context.enter();
        try {
            Scriptable scope = cx.initStandardObjects(null);
            Object cxResultObject = cx.evaluateString(scope, cond
            /** * conditionString ** */
            , "<cmd>", 1, null);
            resultStr = Context.toString(cxResultObject);

            if (resultStr.equals("false")) { //$NON-NLS-1$
                result = false;
            } else if (resultStr.equals("true")) { //$NON-NLS-1$
                result = true;
            } else {
                throw new Exception(" BAD CONDITION :: " + cond + " :: expected true or false");
            }

            logger.debug("    >> evaluate Condition -  [ " + cond + "] results is  [" + result + "]");
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
        } finally {
            Context.exit();
        }

        return result;
    }

    private static boolean evaluateExpression(String cond) {
        return cond.equalsIgnoreCase("true"); // $NON-NLS-1$
    }

    /**
     * This is overriding the parent method. IsDone indicates whether the
     * termination condition is reached. I.e. if the condition evaluates to
     * False - then isDone() returns TRUE
     */
    @Override
    public boolean isDone() {
        // boolean result = true;
        // try {
        // result = !evaluateCondition();
        // } catch (Exception e) {
        // logger.error(e.getMessage(), e);
        // }
        // setDone(true);
        // return result;
        // setDone(false);
        return false;
    }

    /**
     * @see org.apache.jmeter.control.Controller#next()
     */
    @Override
    public Sampler next() {
        // We should only evalute the condition if it is the first
        // time ( first "iteration" ) we are called.
        // For subsequent calls, we are inside the IfControllerGroup,
        // so then we just pass the control to the next item inside the if control
        boolean result = true;
        if(isEvaluateAll() || isFirst()) {
            result = isUseExpression() ? 
                    evaluateExpression(getCondition())
                    :
                    evaluateCondition(getCondition());
        }

        if (result) {
            return super.next();
        }
        try {
            return nextIsNull();
        } catch (NextIsNullException e1) {
            return null;
        }
    }

    public boolean isEvaluateAll() {
        return getPropertyAsBoolean(EVALUATE_ALL,false);
    }

    public void setEvaluateAll(boolean b) {
        setProperty(EVALUATE_ALL,b);
    }

    public boolean isUseExpression() {
        return getPropertyAsBoolean(USE_EXPRESSION, false);
    }

    public void setUseExpression(boolean selected) {
        setProperty(USE_EXPRESSION, selected, false);
    }
}