Clac.java

import java.util.Random;
import java.util.Scanner;

public class Clac {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		while(true) {
			String userChoice = inputHandler(input, "Enter your choice (rock, paper, scissors) or 'exit' to quit:\t");
			if (userChoice.equals("exit")) {
				System.out.println("Game exited. Cya!");
				break;
			}
			String result = playGame(userChoice);
			System.out.println(result);
			System.out.print("Do you want to play again? (yes/no)\t");
			String playAgain = input.nextLine().toLowerCase();
			if (!playAgain.equals("yes")) {
				System.out.println("Game exited. Cya!");
				break;
			}
		}
		input.close();
	}

	public static String playGame(String userChoice) {
		Random random = new Random();
		int computerRandom = random.nextInt(3);
		String computerChoice = computerRandGen(computerRandom);
		return winner(userChoice, computerChoice);
	}

	public static String inputHandler(Scanner input, String prompt) {
		String userChoice;

		while(true) {
			System.out.print(prompt);
			userChoice = input.nextLine().toLowerCase();

			if (userChoice.equals("exit")) {
				return userChoice;
			}

			if (!userChoice.equals("rock") && !userChoice.equals("paper") && !userChoice.equals("scissors")) {
				System.out.println("Invalid choice. Please try again.");
				continue;
			}
			break;
		}
		return userChoice;
	}

	public static String computerRandGen(int randNum) {
		String computerChoice = "";
		if (randNum == 0) {
			computerChoice = "rock";
		} else if (randNum == 1) {
			computerChoice = "paper";
		} else {
			computerChoice = "scissors";
		}
		System.out.print("Computer chose: " + computerChoice + ". ");
		return computerChoice;
	}

	public static String winner(String userChoice, String computerChoice) {
		int userScore = 0;
		int computerScore = 0;
		boolean userWinChk = (
                        (userChoice.equals("rock") && computerChoice.equals("scissors")) ||
                        (userChoice.equals("paper") && computerChoice.equals("rock")) ||
                        (userChoice.equals("scissors") && computerChoice.equals("paper"))
                        );
		if (userChoice.equals(computerChoice)) {
			return "It's a tie!";
		} else if (userWinChk == true) {
			userScore++;
			return "YOU WIN!";
		} else {
			computerScore++;
			return "COMPUTER WINS!";
		}
	}
}