在測試過程中需要將一些資料寫入CSV檔案中以在另一些Thread Group中使用, 所以Google了一個使用BeanShell的寫入CSV檔案的方法, 這個方法可以放在BeanShell post process, BeanShell Assertion裡面都可以, 在在另外的Thread Group就可以使用CSV Data Set Config來讀取它:

import java.io.FileWriter;
import java.util.Arrays;
import java.io.Writer;
import java.util.List;

//Default separator
char SEPARATOR = ',';

//function write line in csv
public void writeLine(FileWriter writer, String[] params, char separator)
{
   boolean firstParam = true;

   StringBuilder stringBuilder = new StringBuilder();
   String param = "";
   
   for (int i = 0; i < params.length; i++)
   {
      //get param
      param = params[i];
      log.info(param);
       
         //if the first param in the line, separator is not needed
       if (!firstParam) 
       {
           stringBuilder.append(separator);
       }

         //Add param to line
       if (param != ${parentSpaceId}){
       	stringBuilder.append(param);
       }
      
       firstParam = false;
   }

   //prepare file to next line
   stringBuilder.append("\n");

   //add to file the line
   log.info(stringBuilder.toString());
   writer.append(stringBuilder.toString());

}

//get path of csv file (creates new one if its not exists)
String csvFile = "./space_id.csv"; // for example '/User/Downloads/blabla.csv'

String title = "space_id\n";
String[] params = "${id_ALL}".split(",");

System.out.println(title);
System.out.println(params);

FileWriter fileWriter = new FileWriter(csvFile);
//writeLine(fileWriter, title , SEPARATOR);
filewriter.write(title)
writeLine(fileWriter, params, SEPARATOR);

//proper close to file
fileWriter.flush();
fileWriter.close();