JMeter example source code file (Function.java)

This example JMeter source code file (Function.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

function, function, invalidvariableexception, invalidvariableexception, list, sampler, sampler, string, string, util

The JMeter Function.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.functions;

import java.util.Collection;
import java.util.List;

import org.apache.jmeter.engine.util.CompoundVariable;
import org.apache.jmeter.samplers.SampleResult;
import org.apache.jmeter.samplers.Sampler;

/**
 * Methods that a function must implement
 */
public interface Function {
    /**
     * Given the previous SampleResult and the current Sampler, return a string
     * to use as a replacement value for the function call. Assume
     * "setParameter" was previously called.
     *
     * This method must be threadsafe - multiple threads will be using the same
     * object.
     */
    public String execute(SampleResult previousResult, Sampler currentSampler) throws InvalidVariableException;

    /**
     * A collection of the parameters used to configure your function. Each
     * parameter is a CompoundVariable and can be resolved by calling the
     * execute() method of the CompoundVariable (which should be done at
     * execution.)
     *
     * @param parameters
     * @throws InvalidVariableException
     */
    public void setParameters(Collection<CompoundVariable> parameters) throws InvalidVariableException;

    /**
     * Return the name of your function. Convention is to prepend "__" to the
     * name (ie "__regexFunction")
     */
    public String getReferenceKey();

    /**
     * Return a list of strings briefly describing each parameter your function
     * takes. Please use JMeterUtils.getResString(resource_name) to grab a
     * resource string. Otherwise, your help text will be difficult to
     * internationalize.
     *
     * This list is not optional. If you don't wish to write help, you must at
     * least return a List containing the correct number of blank strings, one
     * for each argument.
     */
    public List<String> getArgumentDesc();
}