JMeter example source code file (LoopController.java)

This example JMeter source code file (LoopController.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

booleanproperty, continue_forever, io, loopcontroller, nextisnullexception, non-nls-1, non-nls-1, override, override, sampler, sampler, serializable, string, string, stringproperty

The JMeter LoopController.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.BooleanProperty;
import org.apache.jmeter.testelement.property.IntegerProperty;
import org.apache.jmeter.testelement.property.JMeterProperty;
import org.apache.jmeter.testelement.property.StringProperty;

/**
 * Class that implements the Loop Controller.
 */
public class LoopController extends GenericController implements Serializable {

    private final static String LOOPS = "LoopController.loops"; // $NON-NLS-1$

    private static final long serialVersionUID = 232L;

    /*
     * In spite of the name, this is actually used to determine if the loop controller is repeatable.
     *
     * The value is only used in nextIsNull() when the loop end condition has been detected:
     * If forever==true, then it calls resetLoopCount(), otherwise it calls setDone(true).
     *
     * Loop Controllers always set forever=true, so that they will be executed next time
     * the parent invokes them.
     *
     * Thread Group sets the value false, so nextIsNull() sets done, and the Thread Group will not be repeated.
     * However, it's not clear that a Thread Group could ever be repeated.
     */
    private final static String CONTINUE_FOREVER = "LoopController.continue_forever"; // $NON-NLS-1$

    private transient int loopCount = 0;

    public LoopController() {
        setContinueForever_private(true);
    }

    public void setLoops(int loops) {
        setProperty(new IntegerProperty(LOOPS, loops));
    }

    public void setLoops(String loopValue) {
        setProperty(new StringProperty(LOOPS, loopValue));
    }

    public int getLoops() {
        try {
            JMeterProperty prop = getProperty(LOOPS);
            return Integer.parseInt(prop.getStringValue());
        } catch (NumberFormatException e) {
            return 0;
        }
    }

    public String getLoopString() {
        return getPropertyAsString(LOOPS);
    }

    /**
     * Determines whether the loop will return any samples if it is rerun.
     *
     * @param forever
     *            true if the loop must be reset after ending a run
     */
    public void setContinueForever(boolean forever) {
        setContinueForever_private(forever);
    }

    private void setContinueForever_private(boolean forever) {
        setProperty(new BooleanProperty(CONTINUE_FOREVER, forever));
    }

    private boolean getContinueForever() {
        return getPropertyAsBoolean(CONTINUE_FOREVER);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Sampler next() {
        if(endOfLoop()) {
            if (!getContinueForever()) {
                setDone(true);
            }
            return null;
        }
        return super.next();
    }

    private boolean endOfLoop() {
        final int loops = getLoops();
        return (loops > -1) && (loopCount >= loops);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected Sampler nextIsNull() throws NextIsNullException {
        reInitialize();
        if (endOfLoop()) {
            if (!getContinueForever()) {
                setDone(true);
            } else {
                resetLoopCount();
            }
            return null;
        }
        return next();
    }

    protected void incrementLoopCount() {
        loopCount++;
    }

    protected void resetLoopCount() {
        loopCount = 0;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected int getIterCount() {
        return loopCount + 1;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void reInitialize() {
        setFirst(true);
        resetCurrent();
        incrementLoopCount();
        recoverRunningVersion();
    }
}