java - 程序循环而不运行完整代码

Question

我正在为一个项目编写一个异常类，并且被一个问题难住了。该类要求提供一个包含银行账户的文件名，读取该文件，并检查它们是否符合特定条件。如果它们不满足这些条件之一，则会抛出 BankAccountException 类型的错误，这是一个自定义错误类，它只是扩展 Exception 类并进行重命名。我遇到的问题是，一旦我输入文件名，程序就会立即询问另一个文件的名称。我已经坐了一段时间了，无法弄清楚，任何帮助将不胜感激。

   import java.util.*;


 import java.io.*;

   public class BankAccountProcessor{


  public static void main(String[] args){
     boolean runProgram = true;
     Scanner input = new Scanner(System.in);
     String filename;

     while (runProgram = true){
        try{
           System.out.println("Please enter the name of the file you want to parse.");
           filename = input.next();
           File file = new File(filename);
           Scanner inputFile = new Scanner(file);
           while (inputFile.hasNext()){
              String accountLine = inputFile.nextLine();
                    if (BankAccountProcessor.isValid(accountLine) == true){
                        System.out.println("Line " + accountLine + " has been processed.");
                    }
                    runProgram = false;
           }
        }
           catch(FileNotFoundException e){
              System.out.println("That file does not exist");
           }
           catch(BankAccountException e){

           }
     }
  }

  private static boolean isValid(String accountLine) throws BankAccountException{
     StringTokenizer stringToken = new StringTokenizer(accountLine, ";");
     String tokenOne = stringToken.nextToken();
     String tokenTwo = stringToken.nextToken();
     if (stringToken.countTokens() != 2){
        throw new BankAccountException("Invalid Bank Account Info");
     }
     else if (tokenOne.length() != 10){
        throw new BankAccountException("Invalid Bank Account Info: Account Number is not 10 digits.");
     }
     else if (tokenTwo.length() < 3){
        throw new BankAccountException("Invalid Bank Account Info: Name must be more than 3 letters.");
     }
     else if (BankAccountProcessor.hasLetter(tokenOne) == true){
        throw new BankAccountException("Invalid Bank Account Info: Account Number must be all digits.");
     }
     else if (BankAccountProcessor.hasDigit(tokenTwo) == true){
        throw new BankAccountException("Invalid Bank Account Info: Account Name cannot have digits.");
     }
     return true;
  }

  private static boolean hasDigit(String str){
     for (char c : str.toCharArray()){
        if (Character.isDigit(c)){
           return true;
        }
     }
     return false;
  }

  private static boolean hasLetter(String str){
     for (char c : str.toCharArray()){
        if (Character.isLetter(c)){
           return true;
        }
     }
     return false;
  }


 }

Answer 1

您在每个循环中使用 = 运算符将 true 分配给 runProgram 变量。结果是 true 所以你的 while 循环将永远循环。使用 == 运算符进行比较:

while (runProgram == true)

或者更简单地说，

while (runProgram)