Jmeter的预处理器主要是用来在采样器（sample）被执行之前做一些额外的工作，比如参数化等等。
本文写一个例子来说明如何增加一个预处理器，需求如下：我们想在执行采样器前读取Excel文件中的数据作为参数，此预处理器可以配合While循环控制器使用，每次循环读取excel中的一行数据。
@GUIMenuSortOrder(5) public class ExcelDataPreProcessor extends AbstractTestElement implementsCloneable, PreProcessor, TestBean {private static final Logger log = LoggerFactory.getLogger(ExcelDataPreProcessor.class);private String filename = ""; // file to source (overrides script)private static final long serialVersionUID = 233L;@Overridepublic void process() {//做你想做的一些逻辑System.out.println(this.getFilename());}public String getFilename() {return filename;}public void setFilename(String filename) {this.filename = filename;}@Overridepublic Object clone() {return super.clone();} }
2、写一个对应的Bean
/** 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.modifiers;import java.beans.PropertyDescriptor; import java.util.ResourceBundle;import org.apache.jmeter.testbeans.BeanInfoSupport; import org.apache.jmeter.testbeans.TestBean; import org.apache.jmeter.testbeans.gui.FileEditor;public class ExcelDataPreProcessorBeanInfo extends BeanInfoSupport {public ExcelDataPreProcessorBeanInfo() {this(ExcelDataPreProcessor.class,null);}public ExcelDataPreProcessorBeanInfo(Class<? extends TestBean> beanClass, String[] languageTags) {this(beanClass, languageTags, null);}protected ExcelDataPreProcessorBeanInfo(Class<? extends TestBean> beanClass, String[] languageTags, ResourceBundle rb) {super(beanClass);PropertyDescriptor p;p = property("filename"); // $NON-NLS-1$ p.setValue(NOT_UNDEFINED, Boolean.TRUE);p.setValue(DEFAULT, ""); // $NON-NLS-1$p.setPropertyEditorClass(FileEditor.class);createPropertyGroup("filenameGroup", // $NON-NLS-1$new String[] { "filename" }); // $NON-NLS-1$ }}
这个是描述界面布局和相关元素的的
3，在saveservice.properties文件中增加配置：
ExcelDataPreProcessor=org.apache.jmeter.modifiers.ExcelDataPreProcessor
4、增加一个（ExcelDataPreProcessorResources.properties）多语言支持：
