import java.util.Random;
String phonePrefix="+86191";
String timestamp =System.currentTimeMillis().toString();
Random random=new Random();
int rand1=random.nextInt(10);
int rand2=random.nextInt(10);
String phoneENDS=rand1.toString()+timestamp.substring(7)+rand2.toString();
vars.put(“phone_no”,phonePrefix + phoneENDS);