我把下面的代码放在Eclipse中，但我不能让Eclipse让我把它作为Java应用程序运行。我可以在我写这篇文章的电脑上这样做，但我已经在两台不同的电脑上试过两次了，都没有这个选项。我试过设置一个手动配置来做这件事，我也试过Alt+Shift+X，但都不起作用。我可以在所有这些计算机上正常运行Java应用程序，只是由于某种原因这台不行。

import java.util.Scanner;

public class Donor {

public String name;
public int age;
public double donation;

    Donor() {

    //Initialized to these values for debugging
    name = "NoName";
    age = 0;
    donation = 0;

    }

    Donor(String nameinit, int ageinit, double donationinit) {

    name = nameinit;
    age = ageinit;
    donation = donationinit;

    }

    public String toString() {

    String str = "";

    str += String.format("%s-30%i-6$%d-20", name, age, donation);

    return str;

    }

    public static void main(String[] args) {

    Scanner input = new Scanner(System.in);
    String nameinit = null;
    int ageinit = -1;
    double donationinit = -1;
    String outp = null;

    System.out.print("Enter the donor's name: ");
    nameinit = input.nextLine();

    System.out.print("Enter the donor's age: ");
    ageinit = input.nextInt();

    System.out.print("Enter the donation amount: ");
    donationinit = input.nextDouble();

    Donor d = new Donor(nameinit, ageinit, donationinit);
    outp = d.toString();

    System.out.printf("%s30 %s6 %s10", "Name", "Age", "Donation");
    System.out.print("\n" + outp);

    input.close();

    }

}