Jmeter—实现识别验证码登录

在做自动化测试或压力测试时，验证码总是一个问题。在以往的压力测试经历中，测试一般在独立的测试环境中进行，可以放心禁用验证码或使用万能验证码，这个是最实用的。但是，这两天我尝试了一个使用第三方的图形图像识别工具来完成验证码识别并通过Jmeter完成登录的过程，识别工具的识别成功率有限，因此本篇估计仅能在理论范围内适用。

本篇内容大部分内容来自于该作者的文章：http://blog.csdn.net/xreztento/article/details/48682923

总体目的：给Jmeter写一个后置处理器，用来将上一个请求响应返回的验证码图片识别成文字，并将识别内容保存为Jmeter的一个参数，这个参数供登录post请求进行登录验证，从而完成登录的自动化过程。

工具

（1）第三方图形图像识别工具：tesseract-ocr 下载地址：http://code.google.com/p/tesseract-ocr/downloads/list 基本无法下载，已上传到我的百度网盘

安装后，可以在cmd下试一试是否安装成功：

在cmd下输入命令：tesseract d:\123.jpg result -l eng 意思是将D盘下的123.jpg 识别后放在result.txt下

（2）需要用到的jar包：

Jmeter插件开发相关的jar包： ApacheJmeter_core.jar jorphon.jar logkit-2.0.jar 这些在Jmeter的lib中都有直接导入工程项目即可

图形处理相关的jar包：jai-imageio-1.1.jar swingx-1.6.1.jar 从网上下的，已上传到百度云盘 jar 文件夹下

插件开发

用java IDE新建一个工程项目，实现两个部分，一个是识别图片，一个是Jmeter插件的UI部分。工程项目完成目录为：

package com.test.huu;
import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.Locale;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;

import com.sun.media.imageio.plugins.tiff.TIFFImageWriteParam;

public class ImageIOHelper{
    public static File createImage(File imageFile, String imageFormat) {

        File tempFile = null;
        ImageInputStream iis = null;
        ImageOutputStream ios = null;
        ImageReader reader = null;
        ImageWriter writer = null;

        try {
            Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName(imageFormat);
            reader = readers.next();

            iis = ImageIO.createImageInputStream(imageFile);
            reader.setInput(iis);

            IIOMetadata streamMetadata = reader.getStreamMetadata();
                        TIFFImageWriteParam tiffWriteParam = new TIFFImageWriteParam(Locale.CHINESE);
            tiffWriteParam.setCompressionMode(ImageWriteParam.MODE_DISABLED);
            Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName("tiff");
            writer = writers.next();

            BufferedImage bi = removeBackgroud(reader.read(0));
            IIOImage image = new IIOImage(bi,null,reader.getImageMetadata(0));
            tempFile = tempImageFile(imageFile);

            ios = ImageIO.createImageOutputStream(tempFile);
            writer.setOutput(ios);
            writer.write(streamMetadata, image, tiffWriteParam);

        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if(iis != null){
                try {
                    iis.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if(ios != null){
                try {
                    ios.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if(writer != null){
                writer.dispose();
            }
            if(reader != null){
                reader.dispose();
            }

        }
        return tempFile;
    }

    private static File tempImageFile(File imageFile) {
        String path = imageFile.getPath();
        StringBuffer strB = new StringBuffer(path);
        return new File(strB.toString().replaceFirst("jpg", "tif"));
    }
    
    //给图片降噪 提高识别度
    public static int isFilter(int colorInt) {  
        Color color = new Color(colorInt);
        if ((color.getRed() > 85 && color.getRed() < 255) 
                && (color.getGreen() > 85 && color.getGreen() < 255) 
                && (color.getBlue() > 85 && color.getBlue() < 255)) {  
            return 1;  
        }  
        return 0;
    }
    
    public static BufferedImage removeBackgroud(BufferedImage img)  
            throws Exception {  
        int width = img.getWidth();  
        int height = img.getHeight();  
        for (int x = 0; x < width; ++x) {  
            for (int y = 0; y < height; ++y) {  
                if (isFilter(img.getRGB(x, y)) == 1) {  
                   img.setRGB(x, y, Color.WHITE.getRGB());  
                }
            }  
        }  
        return img;
    } 
    
}

ImageIOHelper.java

package com.test.huu;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class OCR {
    private final String LANG_OPTION = "-l";
    private final String EOL = System.getProperty("line.separator");
    private String tessPath = "D://Program Files (x86)//Tesseract-OCR";

    public String recognizeText(File imageFile,String imageFormat) {
        File tempImage = ImageIOHelper.createImage(imageFile,imageFormat);
        File outputFile = new File(imageFile.getParentFile(),"output" + imageFile.getName());
        StringBuffer sb = new StringBuffer();
        List<String> cmd = new ArrayList<String>();

        cmd.add(tessPath+"//tesseract");
        cmd.add("");
        cmd.add(outputFile.getName());
        cmd.add(LANG_OPTION);
        cmd.add("eng");     
        ProcessBuilder pb = new ProcessBuilder();
        pb.directory(imageFile.getParentFile());

        cmd.set(1, tempImage.getName());
        pb.command(cmd);
        pb.redirectErrorStream(true);

        Process process = null;
        BufferedReader in = null;
        int wait;
        try {
            process = pb.start();
            //tesseract.exe xxx.tif 1 -l eng
            wait = process.waitFor();
            if(wait == 0){
                in = new BufferedReader(new InputStreamReader(new FileInputStream(outputFile.getAbsolutePath()+".txt"),"UTF-8"));
                String str;
                while((str = in.readLine())!=null){
                    sb.append(str).append(EOL);
                }
                in.close();

            }else{

                tempImage.delete();
            }
            new File(outputFile.getAbsolutePath()+".txt").delete();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if(in != null){
                try {
                    in.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }

        tempImage.delete();
        return sb.toString();
    }
}

OCR.java

package com.test.huu;

import java.io.File;  
  
public class TestOCR {  
  
 public static void main(String[] args) {  
        String path = "D://124.jpg";       
        System.out.println("ORC Test Begin......");  
        try {       
            String valCode = new OCR().recognizeText(new File(path), "jpeg");       
            System.out.println(valCode);       
        } catch (Exception e) {    
            e.printStackTrace();    
        }         
        System.out.println("ORC Test End......");  
    }    
  
}

TestOCR.java

package com.test.huu;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.Serializable;

import org.apache.jmeter.processor.PostProcessor;
import org.apache.jmeter.samplers.SampleResult;
import org.apache.jmeter.testelement.AbstractScopedTestElement;
import org.apache.jmeter.threads.JMeterContext;
import org.apache.jmeter.threads.JMeterVariables;
import org.apache.jorphan.logging.LoggingManager;
import org.apache.log.Logger;

public class VcodeExtractor extends AbstractScopedTestElement implements PostProcessor, Serializable{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    /**
     * 
     */
    private static final Logger log = LoggingManager.getLoggerForClass();
    
    @Override
    public void process() {

        // TODO Auto-generated method stub
        JMeterContext context = getThreadContext();
        SampleResult previousResult = context.getPreviousResult();
        if (previousResult == null) {
            return;
        }
        log.debug("VcodeExtractor processing result");

        String status = previousResult.getResponseCode();
        int id = context.getThreadNum();
//        String imageName = id + ".jpg";
        String path = "D://" + id + ".jpg";

        if(status.equals("200")){
            byte[] buffer = previousResult.getResponseData();
            FileOutputStream out = null;
            File file = null;
            try {
                file = new File(path);
                out = new FileOutputStream(file);
                out.write(buffer);
                out.flush();

            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } finally {
                if(out != null){
                    try {
                        out.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }

              try {   
                String vcode = new OCR().recognizeText(file, "jpeg"); 
                vcode = vcode.replace(" ", "").trim();
                
                JMeterVariables var = context.getVariables();
                var.put("vcode", vcode);
//                var.put("vuser", String.valueOf(id));
                } catch (Exception e) {
                    e.printStackTrace();
                }    
        }

    }

}

VodeExtractor.java

package com.test.huu;
import org.apache.jmeter.processor.gui.AbstractPostProcessorGui;
import org.apache.jmeter.testelement.TestElement;

public class VcodeExtractorGUI extends AbstractPostProcessorGui{

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    /**
     * 
     */
    @Override
    public TestElement createTestElement() {
        // TODO Auto-generated method stub
        VcodeExtractor extractor = new VcodeExtractor();
        modifyTestElement(extractor);
        return extractor;
    }

    @Override
    public String getLabelResource() {
        // TODO Auto-generated method stub
        return this.getClass().getName();
    }

    @Override
    public String getStaticLabel() {//设置显示名称
        // TODO Auto-generated method stub
        return "VcodeExtractor";
    }

    @Override
    public void modifyTestElement(TestElement extractor) {
        // TODO Auto-generated method stub
        super.configureTestElement(extractor);

    }
}

VcodeExtractorGUI.java

插件生成

插件开发完成后，在Eclipse中 export-Runnable jar file ，将必要的依赖库加进去，最后会生成一个 .jar 文件

注意：图形相关的jar包直接使用时会报错（Jmeter会报一个错：java.lang.IllegalArgumentException: vendorName == null）最终在网上找到了解决方案

生成jar包后，用解压工具打开，将 /META-INF 目录下的 MANIFEST.MF 文件用编辑器（我用的是sublime）打开，拷贝进去下面一段代码，保存压缩包：

Specification-Title: Java Advanced Imaging Image I/O Tools
Specification-Version: 1.1
Specification-Vendor: Sun Microsystems, Inc.
Implementation-Title: com.sun.media.imageio
Implementation-Version: 1.1
Implementation-Vendor: Sun Microsystems, Inc.

插件插入Jmeter

将 .jar 文件放入Jmeter 安装路径下 lib/ext/ 目录下，重启Jmeter

可以看到，我们新开发的后置处理器 VcodeExtractor