Computer Science 252
Problem Solving with Java
Spring 2015, The College of Saint Rose
Hangman BlueJ Project
Click here to download a BlueJ project for Hangman.
Hangman Source Code
The Java source code for Hangman is below. Click on a file name to download it.
import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;
/* $Id: Hangman.java 2218 2013-10-18 14:06:39Z terescoj $ */
/**
* Example Hangman: play a text-based hangman
*
* @author Jim Teresco, Siena College, CSIS 120, Spring 2011
*
*/
public class Hangman {
// See: http://jbauman.com/aboutgsl.html
private static final String DICTIONARY_FILE = "gsl.txt";
// for a ridiculously large dictionary use "dictionary.txt"
// minimum length of a word to consider
private static final int MIN_WORD_LENGTH = 3;
// largest number of misses allowed to be set
private static final int MAX_MISSES = 26;
public static void main(String[] args) {
System.out.println("Welcome to Hangman!");
// check for debug mode
boolean debug = args.length > 1 && args[0].equals("debug");
// read in the data from the dictionary to an ArrayList
ArrayList<String> words = new ArrayList<String>();
// first, open the file and create a Scanner to read it in
Scanner wordScan = null;
try {
wordScan = new Scanner(new File(DICTIONARY_FILE));
}
catch (FileNotFoundException e) {
System.err.println(e);
System.exit(1);
}
// read the contents of the file one word at a time, skipping
// over words that are too short for use by hangman.
while (wordScan.hasNext()) {
String nextWord = wordScan.next();
if (nextWord.length() >= MIN_WORD_LENGTH) {
words.add(nextWord);
}
}
if (debug) {
System.out.println("Dictionary contains " + words.size() + " words");
}
// create a random number generator to pick a word
// this is how you can get a Random generator without
// objectdraw's RandomIntGenerator
Random r = new Random();
// create a Scanner to read keyboard input
Scanner keyboard = new Scanner(System.in);
// find out the number of guesses allowed before a hangman
int missesAllowed = 0;
while ((missesAllowed < 1) || missesAllowed > MAX_MISSES) {
System.out.print("How many guesses before a hangman? ");
missesAllowed = keyboard.nextInt();
}
boolean gameOver = false;
while (!gameOver) {
// pick the next word
// note: r.nextInt(n) returns an int between 0 and n-1
String theWord = words.get(r.nextInt(words.size()));
if (debug) {
System.out.println("The word is... " + theWord);
}
boolean wordOver = false;
int missesLeft = missesAllowed;
ArrayList<Character> guessed = new ArrayList<Character>();
// keep looping until the word has been guessed or too
// many incorrect guesses have been made
while (!wordOver) {
showGuessed(theWord, guessed);
System.out.println("\nYou have " + missesLeft + " incorrect guesses remaining");
System.out.println(maskWord(theWord, guessed));
boolean guessOK = false;
String guess = null;
while (!guessOK) {
System.out.print("Your guess? ");
guess = keyboard.next().toLowerCase();
// add this guess to our list of guessed letters
if (guessed.contains(guess.charAt(0))) {
System.out.println("You already guessed that!");
}
else {
// insert the guess into the list of guessed
// letters in alphabetical order
int pos = 0;
while (pos < guessed.size() &&
guessed.get(pos) < guess.charAt(0)) {
pos++;
}
guessed.add(pos, guess.charAt(0));
guessOK = true;
}
}
// is the first letter of the response in the word?
if (theWord.indexOf(guess.substring(0,1)) == -1) {
// not in the word
System.out.println("The letter " + guess.charAt(0) + " is not in the word.");
missesLeft--;
if (missesLeft == 0) {
System.out.println("Too bad! HANGMAN! The word was: " + theWord);
wordOver = true;
}
}
else {
// it is in the word
System.out.println("Good - you have a match.");
if (theWord.equals(maskWord(theWord, guessed))) {
System.out.println("You got it! The word was: " + theWord);
wordOver = true;
}
}
}
System.out.print("Play again? ");
String response = keyboard.next();
gameOver = response.equalsIgnoreCase("no");
}
System.out.println("Thanks for playing.");
}
/**
* return a String with the characters not in the list of characters
* replaced with _ characters.
*
* @param word the word to be masked
* @param letters the ArrayList of characters to be revealed
* @return the word with all characters not in letters replaced by _'s
*/
private static String maskWord(String word, ArrayList<Character> letters) {
String answer = "";
for (int i = 0; i<word.length(); i++) {
if (letters.contains(word.charAt(i))) {
answer = answer + word.charAt(i);
}
else {
answer = answer + "_";
}
}
return answer;
}
/**
* Show the list of guessed letters that were not found in the word.
*
* @param theWord the word being guessed
* @param letters the ArrayList of characters guessed so far
*/
private static void showGuessed(String theWord, ArrayList<Character> letters) {
System.out.print("Guessed: ");
for (int i = 0; i<letters.size(); i++) {
if (theWord.indexOf(letters.get(i)) == -1) {
System.out.print(letters.get(i) + " ");
}
}
System.out.println();
}
}