Jmeter自定义函数使用方法

编写获取本地和远程图片流的Jmeter自定义函数
代码如下：

package org.apache.functions;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
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.commons.codec.binary.Base64;

public class ImageLocalBase64 extends AbstractFunction {
	// 显示的参数名字
	private static final List<String> desc = new LinkedList();
	// 显示的函数名字
	private static final String KEY = "__ImageLocalBase64";
	// 参数值
	private Object[] values;

	static {
		desc.add("local path for image");
		desc.add("Name of variable in which to store the result (optional)");
	}

	public String execute(SampleResult paramSampleResult, Sampler paramSampler) throws InvalidVariableException {
		String s = null;
		try {
			String url = ((CompoundVariable) this.values[0]).execute();
			url = new String(url.getBytes("UTF-8"), "UTF-8");
			InputStream inStream = new FileInputStream(url);

			byte[] b = ImageUtil.readInputStream(inStream);
			byte[] bs = Base64.encodeBase64(b);
			s = new String(bs);
			return s;
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (Exception e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		}

		return s;
	}

	// 获取参数值
	public synchronized void setParameters(Collection<CompoundVariable> paramCollection)
			throws InvalidVariableException {
		// 检查参数，我也搞不懂是毛线意思，NND
		checkMinParameterCount(paramCollection, 1);
		this.values = paramCollection.toArray();
	}

	// 返回函数名字
	public String getReferenceKey() {
		return KEY;
	}

	// 返回参数名字
	public List<String> getArgumentDesc() {
		return desc;
	}
}

package org.apache.functions;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
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.commons.codec.binary.Base64;
  
public class ImageRemoteBase64 extends AbstractFunction {  
    //显示的参数名字  
    private static final List<String> desc = new LinkedList();  
    //显示的函数名字  
    private static final String KEY = "__ImageRemoteBase64";  
    //参数值  
    private Object[] values;  
      
    static {  
        desc.add("URL for remote Image");  
        desc.add("Name of variable in which to store the result (optional)");  
    }  
      
    public  String execute(SampleResult paramSampleResult, Sampler paramSampler)  
            throws InvalidVariableException {  
            String s = null;  
        try {  
            String url = ((CompoundVariable)this.values[0]).execute();  
            s = ImageUtil.getImageFromNetByURL1(url);
            return s;
           

        } catch (Exception e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		}  
        return s;  
    }  
  
    //获取参数值  
    public synchronized void setParameters(Collection<CompoundVariable> paramCollection)  
            throws InvalidVariableException {  
        //检查参数，我也搞不懂是毛线意思，NND  
        checkMinParameterCount(paramCollection, 1);  
        this.values = paramCollection.toArray();  
    }  
  
    //返回函数名字  
    public String getReferenceKey() {  
        return KEY;  
    }  
    //返回参数名字  
    public List<String> getArgumentDesc() {  
        return desc;  
    }  
    
    
    
    /**
     * 从输入流中获取数据
     *
     * @param inStream
     *            输入流
     * @return
     * @throws Exception
     */
    public static byte[] readInputStream(InputStream inStream) throws Exception {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[inStream.available()];
        int len = 0;
        while ((len = inStream.read(buffer)) != -1) {
            outStream.write(buffer, 0, len);
        }
        inStream.close();
        return outStream.toByteArray();
    }
      


    
}

package org.apache.functions;

import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.StringUtils;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

public class ImageUtil {

	/**
	 * 根据地址获得数据的字节流
	 *
	 * @param strUrl
	 *            网络连接地址
	 * @return
	 */

	public static String getImageFromNetByURL1(String strUrl) {
		HttpClient httpclient = new DefaultHttpClient();
		HttpGet httpget = new HttpGet(strUrl);
		HttpResponse response;
		String s = null;
		try {
			response = httpclient.execute(httpget);
			HttpEntity entity = response.getEntity();
			if (entity != null) {
				InputStream instream = entity.getContent();
				byte[] b = readInputStream(instream);
				byte[] bs = Base64.encodeBase64(b);
				s = new String(bs);
				return s;
			}
		} catch (ClientProtocolException e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		} catch (IOException e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		} catch (Exception e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		}
		return s;
	}

	/**
	 * 根据地址获得数据的字节流
	 *
	 * @param strUrl
	 *            本地连接地址
	 * @return
	 */
	public static byte[] getImageFromLocalByUrl(String strUrl) {
		try {

			File imageFile = new File(strUrl);
			InputStream inStream = new FileInputStream(imageFile);
			byte[] btImg = readInputStream(inStream);// 得到图片的二进制数据
			return btImg;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 从输入流中获取数据
	 *
	 * @param inStream
	 *            输入流
	 * @return
	 * @throws Exception
	 */
	public static byte[] readInputStream(InputStream inStream) throws Exception {
		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		byte[] buffer = new byte[inStream.available()];
		int len = 0;
		while ((len = inStream.read(buffer)) != -1) {
			outStream.write(buffer, 0, len);
		}
		inStream.close();
		return outStream.toByteArray();
	}

	/**
	 * 将图片写入到磁盘
	 *
	 * @param img
	 *            图片数据流
	 * @param fileName
	 *            文件保存时的名称
	 */
	public static void writeImageToDisk(byte[] img, String zipImageUrl) {
		try {
			File file = new File(zipImageUrl);
			FileOutputStream fops = new FileOutputStream(file);
			fops.write(img);
			fops.flush();
			fops.close();
			System.out.println("图片已经写入" + zipImageUrl);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}

将生成的jar包放置到Jmeter的lib\ext目录下。重启Jmeter后再运行--函数助手模块能够看到自定义的两个函数。
使用时可以用如下方式引用：
${__ImageRemoteBase64(${photoPath},)
其中${photoPath}通过CSV Data Set Config参数化得到的远端图片路径。


心得：
1、httpclient 可以自动对URL字符串中的中文编码进行转码，减少了URL包含中文导致的图片获取不到问题。
2、Jmeter自定义函数的包名必须要包含“functions”，否则Jmeter发现不了该自定义函数。建议包名：package org.apache.functions