（爪哇）扫描仪未从文件中读取 nextDouble（）

问：

我是 Java 的新手，我正在尝试使用扫描仪从文本文件中读取一些数据。扫描程序可以正常读取字符串和整数数据成员，但是当它达到双精度值时，它会引发 InputMismatchException。

文本文件的格式如下所示...

姓氏，名字，0,0.0
史密斯，约翰，10,2.456
琼斯，威廉，15,3.568

这是我的代码...

import java.io.FileNotFoundException;
import java.util.Scanner;
import java.io.File;

public class Student {

    int age;
    double gpa;
    String firstName;
    String lastName;

    public static void main (String[] args) {
        int iNum = 0;
        double dNum = 0.0;
        String str1 = "";
        String str2 = "";
        List<Student> listOfObjects = new ArrayList<>();

        try {
            Scanner src = new Scanner(new
                     File("data.txt")).useDelimiter(",|\r\n|\n");

            while (src.hasNext()) {
                str1 = src.next();  //last name
                str2 = src.next();  //first name
                iNum = src.nextInt();  //age
                dNum = src.nextDouble();  /* gpa - having trouble reading these doubles with Scanner */             

                Student object = new Student(str1, str2, iNum, dNum);
                listOfObjects.add(object); //add new object to list

            }
        } 
        catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        for (Student a: listOfObjects)   // printing the sorted list
            System.out.print(a.getStudentLastName() + ", " +  
            a.getStudentFirstName() +
            ", " + a.getStudentAge() + ", " + a.getStudentGpa() + "\n");
    }

    public Student(String str1, String str2, int iNum, double dNum){
        this.lastName = str1;
        this.firstName = str2;
        this.age = iNum;
        this.gpa = dNum;
    }

    public String getStudentFirstName() {
        return firstName;
    }

    public String getStudentLastName() {
        return lastName;
    }

    public int getStudentAge() {
        return age;
    }

    public double getStudentGpa() {
        return gpa;
    }

我尝试将区域设置设置为 US 并尝试弄乱分隔符，但似乎没有任何效果。