我正处于完成程序的最后一步，但是每当我输入整数(长整型)时，我都会遇到输入不匹配的情况:
Compiler message: "Exception in thread "main" java.util.InputMismatchException: For input string: "4388576018402626"
at java.util.Scanner.nextInt(Scanner.java:2097)
at java.util.Scanner.nextInt(Scanner.java:2050)
at CreditCardValidation.main(CreditCardValidation.java:12)"
我的代码如下:
import java.util.Scanner ; //import Scanner
public class CreditCardValidation {
public static void main (String[] args){
Scanner kbd = new Scanner(System.in) ;
System.out.println("Please enter Creditcard number: " ) ;
int credNumber = kbd.nextInt() ;
boolean n = isValid( credNumber ) ;
if (credNumber == 0 )
System.exit(0) ;
do {
System.out.println("Please enter Creditcard number: " ) ;
credNumber = kbd.nextInt() ;
}
while ( credNumber < 0 ) ;
if (credNumber > 0 )
System.out.print("This credit card number is " + n ) ;
}
/*
Return true is the number is a valid card number.
*/
public static boolean isValid(long number) {
long p = getPrefix(number, 1);
long p2 = getPrefix(number, 2);
int n = getSize(number);
if ((p == 4 || p == 5 || p == 6 || p2 == 37)&& (n < 13 || n > 16) && (((sumOfDoubleEvenPlace(number) + sumOfoddPlace(number))) % 10) == 0)
return true ;
else
return false ;
}
/* The sum of every other digit, doubled, starting with the first digit. */
public static int sumOfDoubleEvenPlace(long number) {
int sum = 0;
int maxDigitLenth = 16;
for (int i = 1; i <= maxDigitLenth; i++)
{
if (i % 2 == 0)
{
sum = sum + getDigit((int)(number % 10) * 2);
}
number /= 10;
}
return sum;
}
/*
Return the number if it is 0-9, otherwise return the sum of
the digits of the number.
*/
public static int getDigit(int number) {
if (number < 10) {
return number;
}
else {
return (number / 10) + (number % 10);
}
}
/*
Return the sum of the odd-place digits.
*/
public static int sumOfoddPlace(long number) {
int maxDigitLength = 16;
int sum = 0;
for (int i = 1; i <= maxDigitLength; i++)
{
if (i % 2 == 1)
{
sum = sum + (int)(number % 10);
}
number /= 10;
}
return sum;
}
/*
Return the number of digits in d
*/
public static int getSize(long d) {
int size = 0 ;
while( d > 0 ) {
d = d / 10 ;
size = size + 1 ;
}
return size ;
}
/*
Return the first k number of digits from number. If the number of digits in number is
less than k, return the number.
*/
public static long getPrefix(long n, int k) {
int f = getSize(n)-k;
long prefix = n/((long)(Math.pow(10, f)));
return prefix;
}
/*
Return true if the digit d is a prefix for number.
*/
public static boolean prefixMatched( long number, int d ) {
if ( d == getPrefix(number, 4))
return true ;
else
return false ;
}
}
感谢您的宝贵时间!
最佳答案
这是因为您输入的值超出了整数值的范围。在这种情况下你需要使用 long。整数的最大值为2147483647。
long credNumber = kbd.nextLong();
..
// in the do while loop also
credNumber = kbd.nextLong() ;
关于java - 扫描长整数，线程中出现异常 "main"java.util.InputMismatchException，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/19698025/