记一次jmeter从txt文本获取数值并给测试计划的变量赋值，jmeter永久性修改变量。

import java.io.File;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.List; private String stringLine=""; public static int getPrice(int k)
{
// /* 读入TXT文件 */
String pathname = "D:\\\\Java\\\\Jmeter\\\\apache-jmeter-5.0\\\\bin\\\\DaiShouFuLuRuYongHu.txt"; // 绝对路径或相对路径都可以，这里是绝对路径
File filename = new File(pathname); // 要读取以上路径的input。txt文件
InputStreamReader reader = new InputStreamReader(new FileInputStream(filename)); // 建立一个输入流对象reader
BufferedReader br = new BufferedReader(reader); // 建立一个对象，它把文件内容转成计算机能读懂的语言
List line = new ArrayList();
List lineint = new ArrayList();
int i=0;
String[] s = br.readLine().split(",");
for(i =0 ; i<s.length; i++){
line.add(s[i]);
}
for (i = 0;i<line.size();i++)
{
//去掉多余的空格
String b = line.get(i).toString().trim();
//转成int并存储
lineint.add(Integer.parseInt(b)+1);
System.out.println(i+"I:"+lineint.get(i));
}
//转成字符串
stringLine = "";
for (i = 0;i<line.size();i++)
{
//转成字符
String b = String.valueOf(lineint.get(i));
//转成String并存储
if(i!=0)
{
stringLine += ",";
}
stringLine+=b;
}
System.out.println(stringLine);return lineint.get(k);
} public static void setTxt()
{
System.out.println("输入中");
File writename = new File("D:\\\\Java\\\\Jmeter\\\\apache-jmeter-5.0\\\\bin\\\\DaiShouFuLuRuYongHu.txt");// 相对路径，如果没有则要建立一个新的output。txt文件
//writename.createNewFile(); // 创建新文件
BufferedWriter out = new BufferedWriter(new FileWriter(writename));
System.out.println("输入中");
out.write(stringLine); // \r\n即为换行
out.flush(); // 把缓存区内容压入文件
out.close(); // 最后记得关闭文件
}//vars.get("${merchantName}");
int cc = getPrice(0);
String aa = vars.get("merchantName");
aa+=cc;
vars.put("merchantName",aa);int dd = getPrice(1);
String ddd = "";
ddd+=dd;
vars.put("SPid",ddd);System.out.println(stringLine);
setTxt();
System.out.println("写入文件成功");