Question

我需要创建一个异常类，当用户输入中有空格用于名称，密码等（所有字符串）时，将抛出异常。我已经编写了我认为必要的所有代码，无论我输入什么，都会抛出异常。

我做错了什么？

以下是代码片段。如果需要整个程序，请告诉我。

EmptyInputException上课：

public class EmptyInputException extends Exception{
public EmptyInputException(){
    super("ERROR: Spaces entered - try again.");
}
public EmptyInputException(String npr){
    super("ERROR: Spaces entered for " + npr + " - Please try again.");
}

}

这里我捕获异常的getInput方法：

 public void getInput() {
    boolean keepGoing = true;

    System.out.print("Enter Name: ");

    while (keepGoing) {

            if(name.equalsIgnoreCase("Admin")){
            System.exit(1);
            }else

        try {
            name = scanner.next();
            keepGoing = false;
            throw new EmptyInputException();

        } catch (EmptyInputException e) {
            System.out.println("ERROR: Please do not enter spaces.");
            keepGoing = true;
        }//end loop
    }
    System.out.print("Enter Room No.:");

    while (keepGoing) {
        if(room.equalsIgnoreCase("X123")){
            System.exit(1);
        }else
        try {
            room = scanner.next();
            if (room.contains(" ")){
                throw new EmptyInputException();
            }else
                keepGoing = false;

        } catch (EmptyInputException e) {
            System.out.println("ERROR: Please do not enter spaces.");
            keepGoing = true;
        }
    }

    System.out.print("Enter Password:");

    while (keepGoing) {
        if(pwd.equals("$maTrix%TwO$")){
            System.exit(1);
        }else
        try {
            pwd = scanner.next();
            keepGoing = false;
            throw new EmptyInputException();
        } catch (EmptyInputException e) {
            System.out.println("ERROR: Please do not enter spaces.");
            keepGoing = true;
        }
    }

}

我觉得我错过了扫描仪输入应包含空格的部分，例如：

if(name.contains(" "))

依旧......

到目前为止，我的输出（例如输入名称后）会说Error: Please do not put spaces.

Answer 1

try {
        name = scanner.next();
        keepGoing = false;
        if(name.contains(" "))
            throw new EmptyInputException();

    }

应该这样做吗？

Answer 2

你的猜测是正确的。

    try {
        name = scanner.next();
        keepGoing = false;
        throw new EmptyInputException(); // You're always going to throw an Exception here.

    } catch (EmptyInputException e) {
        System.out.println("ERROR: Please do not enter spaces.");
        keepGoing = true;
    }

可能是粗心的错误。需要if(name.contains(" "))：D密码块也发生了同样的事情。

Java异常处理（用户输入中的空格）

2 个答案: