java - NoSuchElementException 扫描器 java

Question

我在我的 java 项目中遇到以下异常。

Exception in thread "main" java.util.NoSuchElementException
    at java.util.Scanner.throwFor(Unknown Source)
    at java.util.Scanner.next(Unknown Source)
    at com.ooad.ooadfirstassignment.Employee.readData(Employee.java:25)
    at com.ooad.ooadfirstassignment.Salaried.readData(Salaried.java:16)
    at com.ooad.ooadfirstassignment.Factory.<init>(Factory.java:21)
    at com.ooad.ooadfirstassignment.MainClass.main(MainClass.java:25)

代码如下:

================================================== ======

public class MainClass {

    /**
     * @param args
     */
    public static void main(String[] args) throws IOException
    {
        // TODO Auto-generated method stub
        FileInputStream empTextStreamIn = null;
        try
        {
            empTextStreamIn = new FileInputStream("Employee.txt");
        }
        catch(FileNotFoundException fex)
        {
            System.out.println("Employee File not found");
            fex.printStackTrace();
        }
        Factory f = new Factory(empTextStreamIn);
        empTextStreamIn.close();

    }

}

================================================== =====================

public class Factory 
{
    public Factory(FileInputStream empTextStreamIn) 
    {
        // TODO Auto-generated constructor stub
        int empType;
        String EmpID = null,DeptID = null;
        double salary=0;
        Scanner sc = new Scanner(empTextStreamIn);
        while(sc.hasNextLine())
        {
            empType = sc.nextInt();
            switch (empType) 
            {
                case 1:Salaried salr = new Salaried(empTextStreamIn);
                        salr.readData();

                                      System.out.println("EmpType="+empType+"   EmpID="+EmpID+"   DeptID="+DeptID+"   Salary="+salary);

代码还在继续，所以这是主要部分。

接下来是员工类

public class Employee 
{
    String EmpID, DeptID;   //Unique detail for Employee class

    protected Scanner sc;

    Employee()
    {

    }
    public Employee(FileInputStream empTextStreamIn) 
    {
        // TODO Auto-generated constructor stub
        sc = new Scanner(empTextStreamIn);

    }
    void readData()
    {
        String EmpID = sc.next();
        String DeptID = sc.next();
    }

}

工薪阶层

public class Salaried extends Employee
{
    double salary;  //Unique detail for Salaried class

    public Salaried(FileInputStream empTextStreamIn) 
    {
        super(empTextStreamIn);

    }
    void readData()
    {
        super.readData();
        salary = sc.nextDouble();


    }

}

请帮助我解决问题。

Answer 1

似乎您的测试文件包含的数据少于您尝试读取的数据，因为这就是 this exception is thrown 的原因。最好使用 hasNext() 检查输入是否有任何下一个元素。方法。