Question

我尝试从文件中读取一个字符串，它工作正常，但它不适用于整数。我似乎无法找到问题

public static void main(String[] args) throws FileNotFoundException  {

   File in = new File ("FCITsamba.in.rtf");
    Scanner scanner = new Scanner(in);// Scanner variable to read from the input file
    File outFile = new File("FCITsamba.txt");// the out file 
    PrintWriter out = new PrintWriter(outFile); // Printwriter to write to the file

   int maxAccounts = 0;//maximum number of accounts that can be in the bank
   int maxTransactions = 0;//maximum number of transactions in a given day
   int accNum = 0;
   int transNum = 0;
   int d = 0;
   int k = 0;
   int dayNo = 1;


    if (!in.exists()) {
        System.out.println("Input file, " + in + ", does not exist.");
        System.exit(0);
    }


   maxAccounts = scanner.nextInt();
   maxTransactions = scanner.nextInt();
   d = scanner.nextInt(); //representing the number of days for the simulation
   k = scanner.nextInt();

它给了我这个错误：

Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
 at fcitsamba.FCITsamba.main(FCITsamba.java:43)
Java Result: 1

我尝试输入一个inputMismatchException，但它没有用，我也尝试将它放在if语句中，如下所示：

if(scanner.hasNextInt()){
   maxAccounts = scanner.nextInt();
   maxTransactions = scanner.nextInt();
   d = scanner.nextInt(); //representing the number of days for the simulation
   k = scanner.nextInt();
  }

但它没有效果

这是输入文件：

200
10000
2
11
OPENACCOUNT 1485 Aslam Saeed 2000.0
DEPOSIT 1485 1000.0
...

Answer 1

当您从文件中读取文件时，它无法识别是否正在读取数字或字符串，因此所有内容都将被视为字符串，包括数据文件(200, 10000, 2, 11)中显示的内容。

而不是写作：

d = scanner.nextInt();

试试这个：

d = Integer.parseInt(scanner.nextLine());

Java不会从文件中读取int

1 个答案: