jmeter添加自定义扩展函数之图片base64编码

打开eclipse，新建maven工程，在pom中引入jmeter核心jar包：

<!-- https://mvnrepository.com/artifact/org.apache.jmeter/ApacheJMeter_core -->
<dependency>
    <groupId>org.apache.jmeter</groupId>
    <artifactId>ApacheJMeter_core</artifactId>
    <version>3.2</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.apache.jmeter/ApacheJMeter_functions -->
<dependency>
    <groupId>org.apache.jmeter</groupId>
    <artifactId>ApacheJMeter_functions</artifactId>
    <version>3.2</version>
</dependency>

1. 新建一个包com.mytest.functions，包名要包含functions，因为jmeter.properties对这块有配置，可见该文件的classfinder.functions.contain=.functions.

2. 在该包下新建一个类并继承AbstractFunction，重写该类的所有方法，具体如下：

package com.mytest.functions;

import java.io.FileInputStream;
import java.io.InputStream;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

import org.apache.jmeter.engine.util.CompoundVariable;
import org.apache.jmeter.functions.AbstractFunction;
import org.apache.jmeter.functions.InvalidVariableException;
import org.apache.jmeter.samplers.SampleResult;
import org.apache.jmeter.samplers.Sampler;
import org.apache.jmeter.threads.JMeterVariables;

import sun.misc.BASE64Encoder;

public class MyBase64 extends AbstractFunction{

    //自定义function的描述
    private static final List<String> desc = new LinkedList<String>();
    static {
        desc.add("图片路径");
    }
    static {
        desc.add("图片base64后存放变量");
    }
    private static final String KEY = "__MyBase64";
   
    //存放传入参数的值的变量
    private Object[] values;
    
   
    //描述参数
    public List<String> getArgumentDesc() {
        // TODO Auto-generated method stub
        return desc;
    }

    @Override
    //函数的执行
    public synchronized String execute(SampleResult arg0, Sampler arg1) throws InvalidVariableException {
        // TODO Auto-generated method stub
        JMeterVariables localJMeterVariables = getVariables();
        String str1 = ((CompoundVariable)this.values[0]).execute();

        String str2 = getImgBase64(str1);

        if ((localJMeterVariables != null) && (this.values.length > 1)) {
          String str3 = ((CompoundVariable)this.values[1]).execute().trim();
          localJMeterVariables.put(str3, str2);
        }

        return str2;
    }

    @Override
    public String getReferenceKey() {
        // TODO Auto-generated method stub
        //提供jmeter函数助手显示的名称
        return KEY;
    }

    @Override
    public synchronized void setParameters(Collection<CompoundVariable> arg0) throws InvalidVariableException {
        // TODO Auto-generated method stub
        //检查参数的个数，支持的方法有2个，具体用法参加api：
        /**
         * protected void checkParameterCount(Collection<CompoundVariable> parameters,
                                   int count)
                            throws InvalidVariableException
            Utility method to check parameter counts.
            Parameters:
            parameters - collection of parameters
            count - number of parameters expected
         * */
        //-----------------
        /**
         * 
         * protected void checkParameterCount(Collection<CompoundVariable> parameters,
                                   int min,
                                   int max)
                            throws InvalidVariableException
            Utility method to check parameter counts.
            Parameters:
            parameters - collection of parameters
            min - minimum number of parameters allowed
            max - maximum number of parameters allowed
         * */
        //checkParameterCount(arg0, 1);
        checkParameterCount(arg0, 1, 2);
        //将参数值存入变量中
        this.values = arg0.toArray();

    }
    public String getImgBase64(String filePath) {
        InputStream in = null;
        byte[] data = null;
        String result = null;
        try {
            in = new FileInputStream(filePath);
            data = new byte[in.available()];
            in.read(data);
            in.close();

            BASE64Encoder encoder = new BASE64Encoder();
            result = encoder.encode(data);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
            
        
        return result;
    }

}

3. 由于我写的类没有依赖第三方jar包，引入的jmeter核心包都是jmeter自带的，所以直接导出上面的类为一个jar包，并把这个jar放在jmeter安装目录的apache-jmeter-3.2libext下面

4. 重启jmeter，打开函数助手，可看见如下图：

5. 下面我们测试一下这个函数是否能使用，新建一个http请求，在post请求里分别添加${__MyBase64(D:\aa.jpg,imgresult)}和${imgresult}如下图，注意${__MyBase64(D:\aa.jpg,imgresult)}一定要在上面

6. 运行后可以看到已经成功