定制JMeter取样器

JMeter运行你区定义自己的取样器sampler，方法很简单，只需继承类org.apache.jmeter.protocol.java.sampler.AbstractJavaSamplerClient，并重写若干方法即可。
首先，创建一个maven项目，并加入jmeter相关的依赖包：

 1 <dependencies>
 2     <dependency>
 3         <groupId>org.apache.jmeter</groupId>
 4         <artifactId>ApacheJMeter</artifactId>
 5         <version>2.10</version>
 6     </dependency>
 7     <dependency>
 8         <groupId>org.apache.jmeter</groupId>
 9         <artifactId>ApacheJMeter_core</artifactId>
10         <version>2.10</version>
11     </dependency>
12     <dependency>
13         <groupId>org.apache.jmeter</groupId>
14         <artifactId>ApacheJMeter_http</artifactId>
15         <version>2.10</version>
16     </dependency>
17     <dependency>
18         <groupId>org.apache.jmeter</groupId>
19         <artifactId>ApacheJMeter_java</artifactId>
20         <version>2.10</version>
21     </dependency>
22 </dependencies>

然后，创建一个类，继承自AbstractJavaSamplerClient，并重写setupTest、teardownTest、runTest与getDefaultParameters方法即可

代码示例如下：

 1 package pengliu.me.jmeter.plugins;
 2 
 3 import org.apache.jmeter.config.Arguments;
 4 import org.apache.jmeter.protocol.java.sampler.AbstractJavaSamplerClient;
 5 import org.apache.jmeter.protocol.java.sampler.JavaSamplerContext;
 6 import org.apache.jmeter.samplers.SampleResult;
 7 import org.apache.jorphan.logging.LoggingManager;
 8 import org.apache.log.Logger;
 9 
10 import java.util.Iterator;
11 import java.util.Random;
12 
13 public class MySampler extends AbstractJavaSamplerClient
14 {
15     private static final Logger log = LoggingManager.getLoggerForClass();
16 
17     @Override
18     public void setupTest(JavaSamplerContext context)
19     {
20         Iterator<String> it = context.getParameterNamesIterator();
21         while (it.hasNext())
22         {
23             String paramName =  it.next();
24             this.log.info(String.format("-----------------paramName: %s, paramValue: %s-----------------",
25                     paramName,
26                     context.getParameter(paramName)));
27         }
28 
29         this.log.info(String.format("-----------------Get param 'name' from JMeter: %s-----------------",
30                 context.getParameter("name", "Default Name")));
31         this.log.info(String.format("-----------------Current Thread Id: %s, Start 'setupTest(JavaSamplerContext context)'--------------------",
32                 Thread.currentThread().getId()));
33     }
34 
35     @Override
36     public void teardownTest(JavaSamplerContext context)
37     {
38         this.log.info(String.format("-----------------Current Thread Id: %s, Start 'teardownTest(JavaSamplerContext context)'--------------------",
39                 Thread.currentThread().getId()));
40     }
41 
42     public SampleResult runTest(JavaSamplerContext javaSamplerContext)
43     {
44         SampleResult result = new SampleResult();
45         result.sampleStart();
46         try
47         {
48             Random r = new Random();
49             long sleepTime = (long)r.nextInt(5000);
50             this.log.info(String.format("-----------------Current Thread Id: %s, Running Test, sleep time is %s--------------------",
51                     Thread.currentThread().getId(),
52                     sleepTime));
53             Thread.sleep(sleepTime);
54 
55             if(sleepTime%2 == 0)
56             {
57                 throw new Exception("--------This is my exception from runTest!!!---------");
58             }
59 
60             result.sampleEnd();
61             result.setSuccessful(true);
62             result.setSampleLabel("My Lable: SUCCESS: " + Thread.currentThread().getId());
63         }
64         catch (Throwable e)
65         {
66             result.sampleEnd();
67             result.setSuccessful(false);
68             result.setSampleLabel("My Lable: FAIL: " + Thread.currentThread().getId());
69 
70             e.printStackTrace();
71         }
72 
73         return result;
74     }
75 
76     @Override
77     public Arguments getDefaultParameters() {
78 
79         Arguments params = new Arguments();
80 
81         params.addArgument("name", "edw");
82 
83         return params;
84     }
85 }

其中setupTest与teardownTest方法，在一个线程只被执行一次，无论此Thread Group配置的Loop Count是多少，每个线程只运行一次这两个方法。

其中runTest方法，如果一个线程配置了多次的Loop Count，那么此runTest就会运行多次

其中getDefaultParameters方法，返回的是JMeter界面的参数列表，如下图：

使用”mvn package”命令打包上面的sampler:

将打包好的jar包放到JMeter的lib/ext目录下：

启动JMeter, 并加入一个Java Request的sampler:

Classname选择代码中自定义的sampler类：

配置Thread Group，线程数为２，循环数为５：

选中Java Request这个sampler，可以设置参数name的值

开始执行后，JMeter会产生两个线程，每个线程都跑只跑一遍setupTest与teardownTest方法，但会跑５遍runTest方法

查看JMeter的日志输出：

查看”View Results in Table”中的结果：