Exercise: Hangman

Write the game Hangman as a console application:

Choose a word from an array of words that you define in your source code.
Ask the user to guess letters.
Keep track of the letters guessed and the number of incorrect guesses.
Display the word with guessed letters and stars for unguessed letters.
End the game when the user has either guessed the word or made too many incorrect guesses.

Example program output (user input in green):

Welcome to the Hangman game!
=====================
Word to guess: ****
Guessed characters: 
Lives left: 6
Enter a character: e
Wrong guess!
=====================
Word to guess: ****
Guessed characters: e
Lives left: 5
Enter a character: a
Good guess!
=====================
Word to guess: *a*a
Guessed characters: ea
Lives left: 5
Enter a character: j
Good guess!
=====================
Word to guess: Ja*a
Guessed characters: eaj
Lives left: 5
Enter a character: v
Good guess!
Congratulations! You've guessed the word: Java

Make sure the user enters only one character per guess. If the user enters more than one character, print a message and ask for new input:

Welcome to the Hangman game!
=====================
Word to guess: ****
Guessed characters: 
Lives left: 6
Enter a character: abcdef
Please enter a single character.
=====================
Word to guess: ****
Guessed characters: 
Lives left: 6
Enter a character:

Tell the user if they have already guessed the character:

Welcome to the Hangman game!
=====================
Word to guess: ****
Guessed characters: 
Lives left: 6
Enter a character: j
Good guess!
=====================
Word to guess: J***
Guessed characters: j
Lives left: 6
Enter a character: J
You already guessed that character.
=====================
Word to guess: J***
Guessed characters: j
Lives left: 6
Enter a character:

Methods

You are not allowed to use these methods of String from the Java standard library:

indexOf
contains
toLowerCase
toUpperCase

Instead, write your own methods, for example:

Checks whether haystack contains needle, ignoring differences in upper or lower case:
boolean containsIgnoreCase(String haystack, char needle)
Makes a character lower case (for example, Z → z):
char toLowerCase(char ch)

Using these methods from String is allowed:

charAt
length

Hand in instructions

Make sure your program runs correctly.
Hand in your program by uploading Main.java to Moodle.