Java:NoSuchElementException

Question

我开始通过简单地读取数据文件来做练习。当我运行该程序时，数据文件被读取但没有读取，但出于某种原因我仍然收到“NoSuchElementException”并且我的输出没有按照预期的方式格式化。这是正在发生的事情:

我创建了一个简单的数据文件，如下所示:

Barry Burd
Author
5000.00
Harriet Ritter
Captain
7000.00
Ryan Christman
CEO
10000.00

之后我写了一个简单的“getter”和“setter”程序(代码如下)。

import static java.lang.System.out;

  //This class defines what it means to be an employee

public class Employee {

  private String name;
  private String jobTitle;

  public void setName(String nameIn) {
    name = nameIn;
  }

  public String getName() {
    return name;
  }

  public void setJobTitle(String jobTitleIn) {
    jobTitle = jobTitleIn;
  }

  public String getJobTitle() {
    return jobTitle;
  }

  /*The following method provides the method for writing a paycheck*/

  public void cutCheck(double amountPaid)   {
    out.printf("Pay to the order of %s ", name);
    out.printf("(%s) ***$", jobTitle);
    out.printf("%,.2f\n", amountPaid);
  }

}

很简单。 然后我编写了实际使用这些东西的程序(下面的代码)。

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

public class DoPayroll {

  public static void main(String[] args) throws IOException {
    Scanner diskScanner = new Scanner(new File("EmployeeInfo.txt"));

    for (int empNum = 1; empNum <= 3; empNum++) {
      payOneEmployee(diskScanner);
    }
  }

  static void payOneEmployee(Scanner aScanner) {
    Employee anEmployee = new Employee();

    anEmployee.setName(aScanner.nextLine());
    anEmployee.setJobTitle(aScanner.nextLine());
    anEmployee.cutCheck(aScanner.nextDouble());
    aScanner.nextLine();
  }
}

这是我的输出:

Pay to the order of Exception in thread "main" java.util.NoSuchElementException: No line found
    at java.util.Scanner.nextLine(Scanner.java:1516)
    at DoPayroll.payOneEmployee(DoPayroll.java:25)
    at DoPayroll.main(DoPayroll.java:14)
 Barry Burd ( Author) ***$5,000.00
Pay to the order of  Harriet Ritter ( Captain) ***$7,000.00
Pay to the order of  Ryan Christman ( CEO) ***$10,000.00

编辑 我发现了问题，但我不明白，哈哈。显然，我不得不在数据文件的末尾添加一个空行....为什么？？

Answer 1

I found the problem but I don't understand it lol. Apparently, I had to add a blank line to the end of the data file....why??

因为你是在告诉Scanner输入文件中的salary后面会有一个回车符。但是，对于最后一个条目，没有回车，因此它确定您犯了一个编程错误并抛出一个未经检查的异常。

您可以像这样在您的代码中解决问题:

static void payOneEmployee(Scanner aScanner) {
    Employee anEmployee = new Employee();

    anEmployee.setName(aScanner.nextLine());
    anEmployee.setJobTitle(aScanner.nextLine());
    anEmployee.cutCheck(aScanner.nextDouble());
    if (aScanner.hasNextLine()) {
        aScanner.nextLine();
    }
}