在用户输入不是小数的情况下创建异常

public class NonDecimalInputException extends Exception {
    public NonDecimalInputException(String message) {
        super(message);
    }
}

public class Main {
    public static void main(String[] args) {
        try {
            String userInput = "1234";
            double number = Double.parseDouble(userInput);
            
            if (number % 1 != 0) {
                throw new NonDecimalInputException("Input should not be a decimal.");
            }
            
            // 执行其他逻辑...
        } catch (NonDecimalInputException e) {
            System.out.println("Exception: " + e.getMessage());
            // 处理异常...
        } catch (NumberFormatException e) {
            System.out.println("Exception: Invalid input format.");
            // 处理格式错误异常...
        }
    }
}