Why Do I keep getting nullpointexception java scanner file reader

Asked Mar 26 '20 at 02:10

Active Mar 26 '20 at 02:16

Viewed 11 times

I don't understand why I keep getting the null exception. I've checked for null with while hasNextLine() loop. Here is my code. Please help me out! Thanks!

    public class SpellCheckerTool {

  private HashSet<String> hashedDictionary;
  private ArrayList<String> listDictionary;

  /**
   * Instantiate this SpellCheckerTool.
   * @param dictionaryFileName the dictionary to use for testing
   * spellings
  */
  public SpellCheckerTool(String dictionaryFileName) {
    // inialize both dictionaries
    try{
      Scanner sc = new Scanner(new File(dictionaryFileName));
      while (sc.hasNextLine()){
        String input = sc.nextLine();

        hashedDictionary.add(input);
        listDictionary.add(input);



      }
    }

    catch (FileNotFoundException e){
      System.out.println("File Not Found");
    }

edited Mar 26 '20 at 02:16

blurfus

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asked Mar 26 '20 at 02:10

Bob

2

Where are `hashedDictionary` and `listDictionary` initialized? – Robby Cornelissen Mar 26 '20 at 02:13
it's initialized like this private HashSet hashedDictionary; private ArrayList listDictionary; – Bob Mar 26 '20 at 02:19
Is that correct? – Bob Mar 26 '20 at 02:19
They're only declared that way. You need to initialize them, e.g. `private Set hashedDictionary = new HashSet<>();` – Robby Cornelissen Mar 26 '20 at 02:22
1

I got it. Thanks! rookie mistake... completely forgot about that – Bob Mar 26 '20 at 02:25

Why Do I keep getting nullpointexception java scanner file reader

0 Answers0