How to return an jsonarray in BeanShell PostProcessor for next testcase in jmeter - jmeter

Question

After I get a list like this:
[{
"id": "55af0d89ba411ff8b8000680",
},{
"id": "55af0d89ba411ff8b80006bc",
"object": {
"id": "55af0d89ba411ff8b80006bd",
}
}]
In the BeanShell PostProcessor I have code to return an list Id like this:
import org.json.simple.JSONObject;
import org.json.simple.JSONArray;
import org.json.simple.parser.JSONParser;
import java.util.*;
String response = prev.getResponseDataAsString();
JSONParser parser = new JSONParser();
JSONArray GroupList = (JSONArray) parser.parse(response);
Iterator i = GroupList.iterator;
JSONArray GroupIds = new JSONArray();
while (i.hasNext())
{
JSONObject objGroup = (JSONObject) i.next();
GroupIds.push(objGroup.get("id"));
}
vars.putObject("GroupIds",GroupIds);
For the next test element, I create the foreach Loop controller to loop the GroupIds, but I see in the log, it has error like this:
jmeter.util.BeanShellInterpreter: Error invoking bsh method:
eval Sourced file: inline evaluation of: ``import
org.json.simple.JSONObject; import org.json.simple.JSONArray; import
org. . . . '' : Typed variable declaration : Cannot access field:
iterator, on object:[{
"id": "55af0d89ba411ff8b8000680",
"name": "Companies",
"description": "Contacts of companies",
"type": "Group",
"created_at": "2015-07-22T03:27:05Z",
"updated_at": "2015-07-23T02:45:02Z",
"dominant_gender": "unknown",
"average_age": "?" }, {
"id": "55af0d89ba411ff8b80006bc",
"name": "Subscription",
"description": "Subscription",
"type": "Subscriptions::SubscriptionList",
"average_age": "?",
"subscription": {
"id": "55af0d89ba411ff8b80006bd",
"name": "Subcription 1",
"form_ids": ["5526430cba411ff8c30001cd"]
} }]
jmeter.extractor.BeanShellPostProcessor: Problem in BeanShell script
org.apache.jorphan.util.JMeterException: Error invoking bsh method:
eval Sourced file: inline evaluation of: ``import
org.json.simple.JSONObject; import org.json.simple.JSONArray; import
org. . . . '' : Typed variable declaration : Cannot access field:
iterator, on object:[{
"id": "55af0d89ba411ff8b8000680",
"name": "Companies",
"description": "Contacts of companies",
"type": "Group",
"created_at": "2015-07-22T03:27:05Z",
"updated_at": "2015-07-23T02:45:02Z",
"dominant_gender": "unknown",
"average_age": "?" }, {
"id": "55af0d89ba411ff8b80006bc",
"name": "Subscription",
"description": "Subscription",
"type": "Subscriptions::SubscriptionList",
"average_age": "?",
"subscription": {
"id": "55af0d89ba411ff8b80006bd",
"name": "Subcription 1",
"form_ids": ["5526430cba411ff8c30001cd"]
} }]
What is the problem?

Answer 1

There are few issues with your code:
Iterator i = GroupList.iterator; - parentheses are required as iterator is a method, not field.
GroupIds.push(objGroup.get("id")); - change push to add, there is no push method
Full working code:
String response = prev.getResponseDataAsString();
JSONParser parser = new JSONParser();
JSONArray GroupList = (JSONArray) parser.parse(response);
Iterator i = GroupList.iterator();
JSONArray GroupIds = new JSONArray();
while (i.hasNext()) {
JSONObject objGroup = (JSONObject) i.next();
GroupIds.add(objGroup.get("id"));
}
vars.putObject("GroupIds", GroupIds);
By the way, it isn't very recommended to use Beanshell for under high load as it is not very efficient. For one thread it is OK, but when it comes to immense load - it may become performance bottleneck and may ruin your test. If it is the case - consider switching to JSR223 PostProcessor and "groovy" language instead.
A very little change will be required:
adding groovy-all.jar to JMeter's /lib folder
substitute all Beanshell test elements to JSR223 with "groovy" engine
See Beanshell vs JSR223 vs Java JMeter Scripting: The Performance-Off You've Been Waiting For! article for detailed installation instructions, scripting tips and tricks and different scripting engines performance benchmark.
UPDATE - generate variables for ForEach Controller:
import org.json.simple.parser.JSONParser;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
String response = prev.getResponseDataAsString();
JSONParser parser = new JSONParser();
JSONArray GroupList = (JSONArray) parser.parse(response);
for (int i = 0; i < GroupList.size(); i++) {
JSONObject objGroup = (JSONObject) GroupList.get(i);
vars.put("Group_" + i, objGroup.get("id"));
}
Then add a ForEach Controller and configure it as follows:
Input variable prefix: Group
Start index: -1
Output variable name: CURRENT_GROUP
Add "_" before number - check the box
Use ${CURRENT_GROUP} where required