java - while循环读取csv文件越界

Question

我正在开发一个从包含银行帐户列表的文件中读取的程序。我不断遇到 IndexOutOfBoundsException 错误，但不确定原因。当我将银行账户直接放入代码中(而不是从文件中读取)时，它工作得很好，这让我相信我的 while 循环在某个地方搞砸了。我怀疑它没有正确循环，但我并不肯定。不幸的是，我对 while 循环没有太多经验。

我正在读取的文件，按帐户类型/名称/值(value)/费率的顺序列出:

1,Waterford Ellingsworth,4350.0,0.002
2,Bethanie Treadwell,500.0,0.35
3,Ira Standish,50000,0.1,59,0.1

实际程序本身:

 Scanner infile = new Scanner("‪C:/Users/Josh/Desktop/prog5input.csv");
    while (infile.hasNextLine()) {
        Scanner s2 = new Scanner(infile.nextLine()); // put string from file into second Scanner object
        s2.useDelimiter(",");
        if (s2.hasNextInt()) {
            int type = s2.nextInt(); 
            if (type == 1) {
                String accountHolder = s2.next();
                double accountInitial = s2.nextDouble();
                double accountRate = s2.nextDouble();
                bank.addNewAccount(new SavingsAccount(accountHolder, accountInitial, accountRate));
                // read fields for Type 1 accounts and create new Type 1 object
            }
            else if (type == 2) {
                String accountHolder = s2.next();
                double accountInitial = s2.nextDouble();
                double accountCostPerMonth = s2.nextDouble();
                bank.addNewAccount(new CheckingAccount(accountHolder, accountInitial, accountCostPerMonth));
            }
            else if (type == 3) {
                String accountHolder = s2.next();
                double accountInitial = s2.nextDouble();
                double accountRate = s2.nextDouble();
                int disbursementAge = s2.nextInt();
                double earlyWithdrawalPenalty = s2.nextDouble();
                bank.addNewAccount(new IRAAccount(accountHolder, accountInitial, accountRate, disbursementAge, earlyWithdrawalPenalty));
            }
        } //ends if statement s2.hasNextInt()
        // now go to top of loop, check infile to see if there is another line to read
    } //ends while loop

编辑以包含输出:

Creating accounts...

Performing transactions...
Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
    at java.util.ArrayList.rangeCheck(Unknown Source)
    at java.util.ArrayList.get(Unknown Source)
    at Bank.getAccountByIndex(Bank.java:28)
    at BankDriverFileInput.main(BankDriverFileInput.java:58)

这是我的整个程序的链接:https://drive.google.com/drive/folders/0BysdkYqrEP7kazNhMXpQSzd4bUE?usp=sharing

Answer 1

替换

Scanner infile = new Scanner("‪C:/Users/Josh/Desktop/prog5input.csv");

与

Scanner infile = new Scanner(new FileInputStream("‪C:/Users/Josh/Desktop/prog5input.csv"));

因为您的代码，Scanner 的输入流将是字符串“c:....”，而不是它代表的文件 .