Btukfyl

I'm making an RPG game in Java for a school assignment. In the game I take user input and the first word is the "command word", so I create an enum to convert the strings for user input to enum constants:

public enum CommandWord

{

    GO("go"), QUIT("quit"), HELP("help"), BACK("back"), LOOK("look"), DROP("drop"), GRAB("grab"), USE("use"), UNKNOWN("?");



    private String commandString;



    /*

     * Initialize with the corresponding command string.

     * @param commandString the command string.

     */

    CommandWord(String commandString) {

        this.commandString = commandString;

    }



    public String toString()

    {

        return commandString;

}

Sometimes the second word is a direction following "go" so I have a second enum for directions with more constants:

UP("up"), DOWN("down"), NORTH("north"), SOUTH("south"), EAST("east"), WEST("west"), UNKNOWN("unknown");

I'm trying to come up with the best method for building a HashMap to store strings and the related enum constants. For command words I have this class:

public class CommandWords

{

    // A mapping between a command word and the CommandWord

    // that is associated with it

    private HashMap<String, CommandWord> validCommands;

    /**

     * Constructor - initialise the command words.

     */

    public CommandWords()

    {

        validCommands = new HashMap<>();

        for (CommandWord command : CommandWord.values()) {

            if(command != CommandWord.UNKNOWN) {

                validCommands.put(command.toString(), command);

            }

        }

    } 



    /**

     * Searches the HashMap of valid commands for the supplied word.

     * @param commandWord The word we're searching for.

     * @return The CommandWord that is mapped to the supplied string commandWord,

     *         or UNKNOWN if it is not in valid command.

     */

    public CommandWord getCommandWord(String commandWord)

    {

        CommandWord command = validCommands.get(commandWord);

        if (command!= null) {

            return command;

        }

        else {

            return CommandWord.UNKNOWN;

        }

    }

}

Then I can take userinput and search for the command word, but I can't reuse it for directions, or items, characters etc. I looked at using a generic class but I can't call methods like .values() on it, is there a good way to do this so I can reuse the CommandWords class on different enums?

We have valueOf(String) method on Enum, you don't have to build that map.

For your case, you have a value, and you know which Enum type you would like to convert to. So, just use:

CommandWord.valueOf("QUIT");

Items.valueOf("GEM");

etc..

Enums must be determined at compile-time.