扫描仪方法不返回任何此类元素

Question

我目前有2个班级，分别是商店班级和客户班级。客户是商店的子类别。 shop类包含一个大型扫描器方法，该方法将选择一个文件等，然后转到子类客户以获取其readdata方法，该方法用于将扫描文件中的数据分配给客户类的字段，但是它不能像它应该并且我没有这样的元素异常。

这是我的Shop类扫描仪方法

public void readCustomerData()
{
    FileDialog myFrame = null;
    FileDialog fileBox = new FileDialog(myFrame, "Open", FileDialog.LOAD);        
    //fileBox.setDirectory("");
    fileBox.setVisible(true);
    String fileName = fileBox.getDirectory() + fileBox.getFile();  
    File dataFile = new File (fileName);
    Scanner scanner = null;
    Customer customer = null;
    try{
        scanner = new Scanner (dataFile);
    }
    catch(FileNotFoundException ex)
    {
        System.err.println("FileNotFound exception");
    }
    if(scanner != null)
    {

     while(scanner.hasNext())
     {
        String lineOfText = scanner.nextLine().trim();
        if(!lineOfText.startsWith("//") && (lineOfText.length() > 0))
        {
         Scanner scan = new Scanner (lineOfText);
         scan.useDelimiter("\\s?,\\s?");
         customer = new Customer();
         customer.readCustomerData(scan);
         storeCustomer(customer);
         scan.close();
        }
        // scan.close();

     }
     scanner.close();
    }
}

这是我的客户读取方法

//@Override
public void readCustomerData(Scanner scan)
{
    //super.readCustomerData(scan);
    customerID = scan.next();
    surname = scan.next();
    firstName = scan.next();
    otherInitials = scan.next();
    title = scan.next();
}

如果我尝试使用@Override时出现语法错误，它不允许我将super.readcustomerdata作为其在主类中的无参数方法来调用

Answer 1

您的代码工作正常。我能想象的唯一问题是您的文件格式不适合代码。这是一个完整的示例：

test.txt：

// New customer data\
// data is customerID, surname, firstName, otherInitials, title
unknown, Newton, David, E, Dr
unknown, Gregson, Brian, R T, Mr
unknown, Evans, David, , Dr
unknown, Smith, Sara, C, Ms
1, Muster, Max, Mr., Dr.
2, Frings, Stefan, , ,

Main.java：

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

public class Main
{
    public static void readCustomerData(Scanner scan)
    {
        String customerID = scan.next();
        String surname = scan.next();
        String firstName = scan.next();
        String otherInitials = scan.next();
        String title = scan.next();
        System.out.printf("%s %s %s %s %s\n",customerID,surname,firstName,otherInitials,title);
    }

    public static void main(String[] args) throws Exception
    {
        File dataFile=new File("test.txt");
        Scanner scanner = new Scanner(dataFile);
        while(scanner.hasNext())
        {
            String lineOfText = scanner.nextLine().trim();
            if(!lineOfText.startsWith("//") && (lineOfText.length() > 0))
            {
                Scanner scan = new Scanner (lineOfText);
                scan.useDelimiter("\\s?,\\s?");
                readCustomerData(scan);
                scan.close();
            }
        }
        scanner.close();
    }
}