JMeter - Access variables used in Java - jmeter

Question

I'm new to JMeter. I've a Java code which I've imported as JAR file. There is a variable called output, in which the result is in which the output is received and is printed. I want to access that variable from Jmeter Beanshell. Can anyone help me out with that?
My Java code is as follows:
package co.in;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class RestClientGet_Validate {
// http://localhost:8080/RESTfulExample/json/product/get
public static void main(String[] args) {
try {
URL url = new URL("http://172.16.2.192:8080/pivot_service_1.0/service/validate");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Accept", "application/json");
if (conn.getResponseCode() != 200) {
throw new RuntimeException("Failed : HTTP error code : "
+ conn.getResponseCode());
}
BufferedReader br = new BufferedReader(new InputStreamReader(
(conn.getInputStream())));
String output;
System.out.println("Output from Server .... \n");
while ((output = br.readLine()) != null) {
System.out.println(output);
response = output;
}
conn.disconnect();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}

Answer 1

First of all, be informed that you can execute the request using JMeter's HTTP Request sampler and obtain the output using Regular Expression Extractor
If you're looking for a way to re-use your existing Java code in JMeter scripting test elements:
You need to change return type of your function to String, to wit replace
public static void main(String[] args)
with
public static String main()
You need to add return statement at the end of your function like:
return output;
Once done place the .jar to JMeter Classpath and restart JMeter to pick it up
If everything goes well you should be able to access the value in Beanshell like:
String output = co.in.RestClientGet_Validate.main();
Also be aware that starting from JMeter 3.1 it is recommended to switch to JSR223 Test Elements and Groovy language for scripting so consider migrating from Beanshell ASAP.