Question

我编写了一个程序，允许我输入业务或个人联系人，然后才能查看它们。我已经为不同类型的联系人使用了子类。当我查看联系人时，我希望能够看到它们是商业用途还是个人用途，但是我们无法找到正确的方法。我已经包含了一段代码，显示了我如何输入它们以及我要求它们查看它们。

public static void addContact(ArrayList<Contact> ContactRecords) {
    Scanner textIn = new Scanner(System.in);
    Scanner keyIn = new Scanner(System.in);
    System.out.println("First Name: ");
    String firstName = textIn.nextLine();
    System.out.println("Last Name: ");
    String lastName = textIn.nextLine();
    System.out.println("Address:  ");
    String address = textIn.nextLine();
    System.out.println("Email Address: ");
    String email = textIn.nextLine();
    System.out.println("Phone: ");
    String phone = textIn.nextLine();
    System.out.println("Is this a 1) Personal or 2) Business?");
    int choice = keyIn.nextInt();
    if (choice == 1) {
        System.out.println("Date of Birth:  ");
        String dateOfBirth = textIn.nextLine();
        Personal aPersonal = new Personal(firstName, lastName, address, 
        email, phone, dateOfBirth);
        ContactRecords.add(aPersonal);
    }
    if (choice == 2) {
        System.out.println("Job Title:  ");
        String jobTitle = textIn.nextLine();
        System.out.println("Organization: ");
        String organization = textIn.nextLine();
        Business aBusiness = new Business(firstName, lastName, address, 
        email, phone, jobTitle, organization);
        ContactRecords.add(aBusiness);
    }

}

public static void getRecords(ArrayList<Contact> ContactRecords)
{
    Scanner keyIn = new Scanner(System.in);
    System.out.println("Contacts who have been entered:");
    for (int i = 0; i < ContactRecords.size(); i++) {
        System.out.println(i + ") "+ ContactRecords.get(i).getFirstName() + 
        " " + ContactRecords.get(i).getLastName());
    }
    System.out.println("Please enter the number corresponding to the contact
    you would like to view: ");
    int choice = keyIn.nextInt();

    System.out.println(ContactRecords.get(choice).toString());
}

}

所以现在当我查看我已添加的联系人时，我看到的是名字，姓氏，地址，电子邮件，电话，然后根据联系方式，出生日期（个人）或职位名称和组织（商业）。我还希望看到Business或Personal，当它返回我的联系信息但不确定时。我尝试添加到我的system.out.println ContactRecords.get（choice）.get（Class）但是将其作为类contactlist.personal返回。我只想退回个人

Answer 1

你可以做到

getClass().getSimpleName()

在联系人条目上。但我建议添加一个方法来联系getType（）以返回类

上的静态字符串

public class Business extends Contact {
    private static final String TYPE = "Business";
    ...
    @Override // method on Contact
    public String getType() {
        return TYPE
    }

或返回枚举

public enum ContactType {
    Personal, Bussiness
}

public class Business extends Contact {
    private static final ContactType TYPE = ContactType.Business;
    ...
    @Override // method on Contact
    public ContactType getType() {
        return TYPE
    }

显示联系类型

1 个答案: