Thread: Help with java hangman game(beginner)

I have been assignedfrom my university teacher to write a java source code for a hangman game.I have been stuck on the guess method where the player guess a character(especially when he's right).Here is what I have done so far!

<public class Hangman
{
 
    private static int ALLOWDED_MISTAKES=7;
    private String secretWord;
    private int noOfMistakes;
    private int chances=7-noOfMistakes;
 
    public  Hangman()
    {
        newGame();
    }//Hangman constructor
 
    public void newGame()
    {
        noOfMistakes=0;
        secretWord=Words.randomWord();
                System.out.println();
        System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
        System.out.println("* * * * * * * * * *  N E W   G A M E  * * * * * * * * * *");
        System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
        System.out.println();
        System.out.print("The word is:");
        for (int i=1;i<=secretWord.length();i++)
          System.out.print("_");
        System.out.println();
        System.out.println();
        System.out.println("You have 7 chances to find the word");
        System.out.println("use method \"guess(char c)\" to guess a character");
        System.out.println("from: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z");
        System.out.println("or use method \"giveUp()\" to stop playing");
 
    }//newGame
 
    public void giveUp()
    {
        System.out.println();
        System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
        System.out.println("* * * * * * * * * * * *G I V E  U P * * * * * * * * * * *");
        System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
        System.out.println();
        System.out.println("The hidden word is "+secretWord);
        System.out.println();
        System.out.println("Use method \"newGame()\"to start a new game.");
    }//giveUp
 
 
     public void guess(char c)
 
 
 
 
                if (!Character.isLetter(c)){
                          System.out.println("Only enter letters!");
 
                }            
 
 
 
 
 
                if (secretWord.indexOf(c) == -1){
                        noOfMistakes++;
                        System.out.println("wrong guess,try again");
                        System.out.println("your remaining chances are "+chances);
                                                if (noOfMistakes==ALLOWDED_MISTAKES){
                                System.out.println();
                         System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
                         System.out.println("* * * * * * * * * * * *YOU LOST * * * * * * * * * * *");
                         System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
                         System.out.println();
                         System.out.println("The hidden word is "+secretWord);
                         System.out.println();
                         System.out.println("Use method \"newGame()\"to start a new game.");
                        }
 
 
                }
 
 
 
                }
 
    }//class
}>

Please help me.Feel free to change anything you want but remember this is for a beginner so try to kee it simple.The player has to use the methods by himself.I'm using bluej .Finally the class Words was given by the teacher and is that :

< import java.util.ArrayList;
import java.util.Random;
/**
 * Provides static method for choosing randomly a word from a dictionary
 * 
 * @author (CR) 
 * @version (11/2012)
 */
public class Words
{
   //class variables
   private static ArrayList<String> dictionary=new ArrayList<String>();
   private static Random random=new Random();
 
   /*
    * Generates a list of words
    */
   private static void generateWords()
   {
       String[] words={"ALCOHOL","AMBULANCE","ANSWER", "AUDIENCE", "AUTOMN", 
           "BLANKET", "BRIDGE",
           "CARPENTER", "CHICKEN", "COMFORTABLE", "COMPUTER", "CONFIDENCE", "COUNTRY",
           "DANGEROUS", "DAUGHTER", "DESCRIBE", "DIRECTLY", "DISTANCE",
           "EQUIPMENT", "EXAMPLE", "EXPERIMENT",
           "FAIRYTALE", "FISHERMAN", "GOVERNMENT",
           "IMAGINATION", "IMPORTANCE", "INDUSTRY", "INFLUENCE", "INSTRUMENT",
           "KEYHOLE", "KNOWLEDGE",
           "LANGUAGE", "MACHINE", "NATURAL", "ORDINARY",
           "PICTURE", "PLEASURE", "POPULATION", "POWERFUL", "QUESTION",
           "STRANGE", "SUBSTANCE", "SURFACE", "SURPRISE", "SYSTEM",
           "TEMPERATURE", "TRIANGLE",
           "UNKNOWN", "WORKER", "YOUTHFUL"};
       for(int i=0;i<words.length;i++)
        dictionary.add(words[i]);
   }//generateWords
 
   /**
    * Creates a list of words and picks one in random
    * 
    * @return   the chosen word
    */
   public static String randomWord()
   {
       generateWords();
       return (String) dictionary.get(random.nextInt(dictionary.size()));
   }//randomWord
}//class>

I don't know how to write the code for when the player guess a letter and he is right.How to relpace the proper _ with the letter he guessed!

here's the code of a simple hangman game,I have to do for homework.I'm a beginner and I have stuck in the method guess.

<import java.lang.Object;
/**
 * Write a description of class Hangman here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class Hangman
{
 
    private static int ALLOWDED_MISTAKES=7;
    private String secretWord;
    private int noOfMistakes;
    private int chances=7-noOfMistakes;
 
    public  Hangman()
   {
        newGame();
    }//Hangman constructor
 
    public void newGame()
    {
        noOfMistakes=0;
        secretWord=Words.randomWord();
                System.out.println();
        System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
        System.out.println("* * * * * * * * * *  N E W   G A M E  * * * * * * * * * *");
        System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
        System.out.println();
        System.out.print("The word is:");
        for (int i=1;i<=secretWord.length();i++)
          System.out.print("_ ");
       System.out.println();
        System.out.println();
        System.out.println("You have 7 chances to find the word");
       System.out.println("use method \"guess(char c)\" to guess a character");
        System.out.println("from: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z");
        System.out.println("or use method \"giveUp()\" to stop playing");
 
    }//newGame
 
    public void giveUp()
    {
        System.out.println();
        System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
        System.out.println("* * * * * * * * * * * *G I V E  U P * * * * * * * * * * *");
       System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
        System.out.println();
        System.out.println("The hidden word is "+secretWord);
        System.out.println();
        System.out.println("Use method \"newGame()\"to start a new game.");
    }//giveUp
 
 
     public void guess(char c)
 
 
 
 
 
                if (!Character.isLetter(c)){
                         System.out.println("Only enter letters!");
 
               }
 
 
 
 
 if (secretWord.indexOf(c) == -1){
                        noOfMistakes++;
                        System.out.println("wrong guess,try again");
                        System.out.println("your remaining chances are "+chances);
                                                if (noOfMistakes==ALLOWDED_MISTAKES){
                                System.out.println();
                         System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
                         System.out.println("* * * * * * * * * * * *YOU LOST * * * * * * * * * * *");
                         System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * * * *");
                         System.out.println();
                         System.out.println("The hidden word is "+secretWord);
                         System.out.println();
                         System.out.println("Use method \"newGame()\"to start a new game.");
                        }
 
 
                }
                if (secretWord.indexOf(c) !== -1)
 
 
 
                }
 
   }//class
}>

I don't know how to write the code for when the player guess a letter and he is right.How to relpace the proper _ with the letter he guessed!I have to mainly use the java.lang package. feel free to change whatever you want,but please keep it simple because I'm a beginner.The class Words were given by the professor

<import java.util.ArrayList;
import java.util.Random;
/**
 * Provides static method for choosing randomly a word from a dictionary
 * 
 * @author (CR) 
 * @version (11/2012)
 */
public class Words
{
   //class variables
   private static ArrayList<String> dictionary=new ArrayList<String>();
   private static Random random=new Random();
 
   /*
    * Generates a list of words
    */
   private static void generateWords()
   {
       String[] words={"ALCOHOL","AMBULANCE","ANSWER", "AUDIENCE", "AUTOMN", 
           "BLANKET", "BRIDGE",
           "CARPENTER", "CHICKEN", "COMFORTABLE", "COMPUTER", "CONFIDENCE", "COUNTRY",
           "DANGEROUS", "DAUGHTER", "DESCRIBE", "DIRECTLY", "DISTANCE",
           "EQUIPMENT", "EXAMPLE", "EXPERIMENT",
           "FAIRYTALE", "FISHERMAN", "GOVERNMENT",
           "IMAGINATION", "IMPORTANCE", "INDUSTRY", "INFLUENCE", "INSTRUMENT",
           "KEYHOLE", "KNOWLEDGE",
           "LANGUAGE", "MACHINE", "NATURAL", "ORDINARY",
           "PICTURE", "PLEASURE", "POPULATION", "POWERFUL", "QUESTION",
           "STRANGE", "SUBSTANCE", "SURFACE", "SURPRISE", "SYSTEM",
           "TEMPERATURE", "TRIANGLE",
           "UNKNOWN", "WORKER", "YOUTHFUL"};
       for(int i=0;i<words.length;i++)
        dictionary.add(words[i]);
   }//generateWords
 
   /**
    * Creates a list of words and picks one in random
    * 
    * @return   the chosen word
    */
   public static String randomWord()
   {
       generateWords();
       return (String) dictionary.get(random.nextInt(dictionary.size()));
   }//randomWord
}//class
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