It's not really a problem that I am facing, more like looking for explanation ... I had this
import java.util.*;
import java.io.*;
public class ReadFile {
private static int lines=0;
private static List<String> words=new ArrayList<String>();
private static String fullLine;
private static int indexOfSpace;
private static String getWord;
private static String getHint;
public static void main(String[] args) {
File file = new File("C:\\Users\\User\\eclipse\\readFileAllLines\\words.txt"); //Windows path
try {
Scanner scanner = new Scanner(file);
while (scanner.hasNextLine()) {
String line = scanner.nextLine();
System.out.println(line+" "+lines);
words.add(lines,line);
lines++;
}
scanner.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
fullLine = words.get(0);
indexOfSpace = fullLine.indexOf(" ");
System.out.println(indexOfSpace);
getWord = fullLine.substring(0,indexOfSpace);
getHint = fullLine.substring(indexOfSpace+1);
System.out.println("The word is "+getWord + " and the hint is "+getHint);
}
}
which works great, but notice that I had to declear my list as static to be able to add elements to it(compiler complained if not static)
Then I wanted to merge the code with the logic of my Hangman Game
import java.util.*;
import java.io.*;
class HangmanLogic{
private String[] words = {"iwin","iwin","iwin","iwin"};
private static String wordToGuess;
Random rnd = new Random();
private static String letter;
private int wrongGuesses = 0;
private int guessedLetter;
private ArrayList<String> al = new ArrayList<String>();
private static Hangman hmGUI = new Hangman();
public final String newLine = "\n";
private static int lines=0;
private List<String> linesInFile=new ArrayList<String>();
private static String fullLine;
private static int indexOfSpace;
private static String getWord;
private static String getHint;
HangmanLogic(Hangman hm){
this.hmGUI = hm;
File file = new File("C:\\Users\\User\\eclipse\\readFileAllLines\\words.txt"); //Windows path
try {
Scanner scanner = new Scanner(file);
while (scanner.hasNextLine()) {
String line = scanner.nextLine();
System.out.println(line+" "+lines);
linesInFile.add(lines,line);
lines++;
}
scanner.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
/*
fullLine = linesInFile.get(0);
indexOfSpace = fullLine.indexOf(" ");
System.out.println(indexOfSpace);
getWord = fullLine.substring(0,indexOfSpace);
getHint = fullLine.substring(indexOfSpace+1);
System.out.println("The word is "+getWord + " and the hint is "+getHint);
*/
wordToGuess = words [rnd.nextInt(words.length)]; // Choose a random word from the list
for (int i = 0; i<wordToGuess.length();i++){ //create all letters represented by "_"
al.add(i," _ ");
}
printWordSoFar(al);
hmGUI.updateMessage(newLine);
System.out.println(al);
System.out.println(wordToGuess);
}
public static void main (String[] args){
}
public static String setLetter(String s){
letter = s;
return letter;
}
public String getLetter(){
return letter;
}
public void tryLetter(String s){
if(wordToGuess.contains(letter)){
//guessedLetter = wordToGuess.indexOf(letter); //location of the guessed letter
//al.set(guessedLetter,letter); //replace the "_" with the letter guessed
//printWordSoFar(al);
/* The code up is for single occurance of string, below for multiple*/
String aLetter;
for (int i=0; i<wordToGuess.length();i++){
aLetter = wordToGuess.substring(i,i+1);
if(letter.equals(aLetter)) al.set(i,letter);
}
printWordSoFar(al);
if(!al.contains(" _ ")) { // word completed
hmGUI.updateMessage("Congratulations, you won!");
hmGUI.turnOffLetter();
}
}
else {
wrongGuesses++;
hmGUI.updateMessage("Wrong, try again!"+ wrongGuesses + "Out of 5 wrong attempts."+newLine);
hmGUI.setPicture(hmGUI.getIcon(hmGUI.getAl(),wrongGuesses));
if(wrongGuesses>=5) {
hmGUI.updateMessage("Game over, you Lost!"+newLine);
hmGUI.turnOffLetter();
}
}
}
public void printWordSoFar(ArrayList<String> al){
for (String s : al){
hmGUI.updateMessage(s);
}
hmGUI.updateMessage(newLine);
}
public int getWrongGuesses(){
return wrongGuesses;
}
}
Sorry for messy code, just added it and faced the problem, from my previous file list was static, when I added it here the compiler gives errors as follows:
C:\Users\User\eclipse\Hangman>java HangmanLogic
word1 hint1 0
Exception in thread "main" java.lang.ExceptionInInitializerError
Caused by: java.lang.NullPointerException
at HangmanLogic.<init>(HangmanLogic.java:37)
at Hangman.<init>(Hangman.java:15)
at HangmanLogic.<clinit>(HangmanLogic.java:12)
Notice it read the first line of the file and then gave an error
This was pointing at the line where I add elements to my list, as an instinct I just removed "static" and it worked
C:\Users\User\eclipse\Hangman>java HangmanLogic
word1 hint1 0
word2 hint2 1
word3 hint3 2
word4 hint4 3
word5 hint5 4
[ _ , _ , _ , _ ]
iwin
So, I am confused how did "static" have an influence of writing to the list in a constructor while it was required when I was added elements in main() ?
