java - 如何将字符串格式化为强加格式？

Question

我有一个作业需要输入验证。 如何格式化字符串以仅接受一种格式类型，例如:AA-1234？

private void validate() {

    Scanner in = new Scanner(System.in);
    System.out.println("Enter the first name:");
    String firstName = in.next();
    System.out.println("Enter the last name:");
    String lastName = in.next();
    System.out.println("Enter the ZIP code");
    String zipCode = in.next();
    System.out.println("Enter the employee ID ");
    String employeeID = in.next();

    if (firstName.length() < 2 | !firstName.matches("[a-zA-z]+")) {
        System.out.println("'" + firstName + "' is not a valid name.Is too short.");
    }
    if (lastName.length() < 2 | !lastName.matches("[a-zA-z]+")) {
        System.out.println("'" + lastName + "' is not a valid name.Is too short.");
    }
    if (!zipCode.matches("[0-9]+")){
        System.out.println("The ZIP code must be numeric.");
    }
    if (!employeeID.matches("%d%d%c%c%c")){
        System.out.println(employeeID +" is not a valid ID format.");
        System.out.println("The ID format should be AA-1234(LetterLetter-NumberNumberNumberNumber)");
    }


}

所以我希望我的方法只接受格式为 AA-1234 的 ID 值，如果格式不同，则打印一条消息，告诉您“您的 ID 格式无效”

Answer 1

使用正则表达式。两个“A-Z”，一个破折号，然后是四位数字。比如，

if (!employeeID.matches("[A-Z]{2}-\\d{4}")){
    System.out.println(employeeID +" is not a valid ID format.");
    System.out.println("The ID format should be AA-1234(LetterLetter-NumberNumberNumberNumber)");
}