无法读取.csv文件。从JOptionPane切换到控制台I/O后出现FileNotFoundException错误

Question

以下是同一方法的两个版本。第一个使用JOptionPane，第二个使用控制台。他们应该从用户输入中获取文件路径（字符串）以查找文件并读取它。

第一种方法工作得很好，但是使用控制台第二种方法给了我一个FileNotFoundException异常错误。为什么第二个如果两者几乎完全一样就不工作？

//使用JOptionPane ///////////////////// ///////////////////////

公共无效addFromFile（）{

String[] option1 = { "Go back to Main Manu", "Continue" }; 

    int choice4 = JOptionPane.showOptionDialog(null, 
      "Warning: this method will delete existing data before it add file data", "Monster Database", 
      JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, option1, null); 

    if (choice4 == 0) 
     monitor(); 

    if (choice4 == 1) { 

     monsterAttackList.clear(); 

     Scanner input = new Scanner(System.in); 
     String filePath = JOptionPane.showInputDialog(null, "Enter a filepath"); 

     File inFile = new File(filePath); 

     try { 
      Scanner fileReader = new Scanner(inFile); 

      String line; 
      String[] part; 
      int attackID; 
      String monster; 
      String date; 
      String location; 
      String reporter; 

      while (fileReader.hasNextLine()) { 
       line = fileReader.nextLine(); 
       part = line.split(","); 
       attackID = Integer.parseInt(part[0]); 
       monster = part[1]; 
       date = part[2]; 
       location = part[3]; 
       reporter = part[4]; 

       monsterAttackList.add(new MonsterAttack(attackID, monster, date, location, reporter)); 
      } 

      fileReader.close(); // Close to unlock. 
      input.close(); 

     } catch (IOException e) { 
      JOptionPane.showMessageDialog(null, "filepath is not valid"); 
      System.err.println(e); 

     } 
    } 

} 

// USING SCANNER ///// ////////////////////////////////////////////////// ////////////////////

public void addFromFile() { 

    System.out.println("Warning: this method will delete existing data before it add file data"); 
    System.out.println("\n1. Go back to Main Manu" + "\n2. Continue \n"); 

    Scanner input = new Scanner(System.in); 
    int choice4 = input.nextInt(); 


    if (choice4 == 1) 
     monitor(); 

    if (choice4 == 2) { 

     monsterAttackList.clear(); 

     System.out.println("Enter a filepath"); 

     String filePath = input.nextLine(); 

     File inFile = new File(filePath); 

     try { 
      Scanner fileReader = new Scanner(inFile); 

      String line; 
      String[] part; 
      int attackID; 
      String monster; 
      String date; 
      String location; 
      String reporter; 

      while (fileReader.hasNextLine()) { 
       line = fileReader.nextLine(); 
       part = line.split(","); 
       attackID = Integer.parseInt(part[0]); 
       monster = part[1]; 
       date = part[2]; 
       location = part[3]; 
       reporter = part[4]; 

       monsterAttackList.add(new MonsterAttack(attackID, monster, date, location, reporter)); 
      } 

      fileReader.close(); // Close to unlock. 
      input.close(); 

     } catch (IOException e) { 

      System.out.println("filepath is not valid"); 
      System.err.println(e); 

     } 
    } 

} 

Answer 1

你会希望把调用input.nextLine()每次致电input.nextInt()后。 NextInt不使用换行符，只使用数字。