Fix bugs from SonarQube

Author: Prototype206

app/src/main/java/hexlet/code/App.java

@@ -8,49 +8,49 @@
 
 public class App {
 	public static void main(String[] args) {
-		Scanner scanner = new Scanner(System.in);
-		try {
-		System.out.println("Please enter the game number and press Enter.");
-		System.out.print("1 - Greet\n2 - Even\n3 - Cacl\n4 - GCD\n5 - Progression\n0 - Exit\nYour choice: ");
-		int usersChoise = 0;
 
-		try {
-			usersChoise = Integer.parseInt(scanner.nextLine());
-		}
-		catch(NumberFormatException e){
-			System.out.println("Wrong input! You need to enter a number");
-		}
-		
-		switch(usersChoise){
-		case 1:
-			Cli.greetings(scanner);
-			break;
-		case 2:
-			Cli.greetings(scanner);
-			Even.startGameEven();
-			Engine.runGame(Engine.EVEN_GAME_NUMBER, scanner);
-			break;
-		case 3:
-			Cli.greetings(scanner);
-			Calc.startGameCalc();
-			Engine.runGame(Engine.CALC_GAME_NUMBER, scanner);
-			break;
-		case 4:
-			Cli.greetings(scanner);
-			GCD.startGameGCD();
-			Engine.runGame(Engine.GCD_GAME_NUMBER, scanner);
-			break;
-		case 5:
-			Cli.greetings(scanner);
-			Progression.startGameProgression();
-			Engine.runGame(Engine.PROGRESSION_GAME_NUMBER, scanner);
-			break;
-		case 0:
-			break;
-		}
-		}
-		finally {
-			scanner.close();
+		try(Scanner scanner = new Scanner(System.in)) {
+			
+			System.out.println("Please enter the game number and press Enter.");
+			System.out.print("1 - Greet\n2 - Even\n3 - Cacl\n4 - GCD\n5 - Progression\n0 - Exit\nYour choice: ");
+			int usersChoise = 0;
+			
+			try {
+				usersChoise = Integer.parseInt(scanner.nextLine());
+			}
+			catch(NumberFormatException e){
+				System.out.println("Wrong input! You need to enter a number");
+			}
+			
+			switch(usersChoise){
+			case 1:
+				Cli.greetings(scanner);
+				break;
+			case 2:
+				Cli.greetings(scanner);
+				Even.startGameEven();
+				Engine.runGame(Engine.EVEN_GAME_NUMBER, scanner);
+				break;
+			case 3:
+				Cli.greetings(scanner);
+				Calc.startGameCalc();
+				Engine.runGame(Engine.CALC_GAME_NUMBER, scanner);
+				break;
+			case 4:
+				Cli.greetings(scanner);
+				GCD.startGameGCD();
+				Engine.runGame(Engine.GCD_GAME_NUMBER, scanner);
+				break;
+			case 5:
+				Cli.greetings(scanner);
+				Progression.startGameProgression();
+				Engine.runGame(Engine.PROGRESSION_GAME_NUMBER, scanner);
+				break;
+			case 0:
+				break;
+			default:
+				throw new IllegalArgumentException("Unknown choise number " + usersChoise);
+			}
 		}
 	}
 }

app/src/main/java/hexlet/code/Cli.java

@@ -2,9 +2,13 @@
 
 import java.util.Scanner;
 
-public class Cli {
+public final class Cli {
 	public static String userName;
 
+	private Cli() {
+		throw new AssertionError("Utility class instantiation prohibited");
+	}
+	
 	public static void greetings(Scanner scanner) {
 		System.out.println("Welcome to the Brain Games!");
 		System.out.print("May I have your name? ");

app/src/main/java/hexlet/code/Engine.java

@@ -7,7 +7,7 @@
 import hexlet.code.games.GCD;
 import hexlet.code.games.Progression;
 
-public class Engine {
+public final class Engine {
 	private static int scoreCounter = 0;
 	private static int scoreToWin = 3;
 	private static StringBuilder correctAnswer = new StringBuilder();
@@ -17,6 +17,10 @@ public class Engine {
 	static final int GCD_GAME_NUMBER = 4;
 	static final int PROGRESSION_GAME_NUMBER = 5;
 
+	private Engine() {
+		throw new AssertionError("Utility class instantiation prohibited");
+	}
+	
 	public static void runGame(int gameNumber, Scanner scanner) {
 		for(int i = 0; i<scoreToWin; i++) {
 			correctAnswer.setLength(0);
@@ -35,6 +39,9 @@ public static void runGame(int gameNumber, Scanner scanner) {
 			case PROGRESSION_GAME_NUMBER:
 				correctAnswer.append(Progression.generateCorrectAnswer());
 				Progression.generateProgression();
+				break;
+			default:
+				throw new IllegalArgumentException("Unknown number of game " + gameNumber);
 			}
 
 			System.out.print("Your answer: ");

app/src/main/java/hexlet/code/games/Calc.java

@@ -1,13 +1,17 @@
 package hexlet.code.games;
 
-public class Calc {
+public final class Calc {
 	private static int minValue = 0;
 	private static int maxValue = 2;
 	private static int operationNumber;
 	private static int correctAnswer = 0;
 	private static int numberOne;
 	private static int numberTwo;
 
+	private Calc() {
+		throw new AssertionError("Utility class instantiation prohibited");
+	}
+	
 
 	public static void startGameCalc() {
 		System.out.println("What is the result of the expression?");
@@ -33,6 +37,8 @@ public static String generateCorrectAnswer() {
 					System.out.println(" * " + numberTwo);
 					correctAnswer = numberOne * numberTwo;
 					break;
+				default:
+					throw new IllegalArgumentException("Unknown number of operation " + operationNumber);
 			}
 			return String.valueOf(correctAnswer);
 		}

app/src/main/java/hexlet/code/games/Even.java

@@ -1,10 +1,14 @@
 package hexlet.code.games;
 
-public class Even {
+public final class Even {
 	private static int evenDivisor = 2;
 	private static int oddRemainder = 1;
 	private static StringBuilder correctAnswer = new StringBuilder();
 
+	private Even() {
+		throw new AssertionError("Utility class instantiation prohibited");
+	}
+	
 	public static void startGameEven() {
 		System.out.println("Answer \'yes\' if the number is even, otherwise answer \'no\'.");
 	}

app/src/main/java/hexlet/code/games/GCD.java

@@ -1,10 +1,14 @@
 package hexlet.code.games;
 
-public class GCD {
+public final class GCD {
 	private static int numberA;
 	private static int numberB;
 	private static int numberC;
 
+	private GCD() {
+		throw new AssertionError("Utility class instantiation prohibited");
+	}
+	
 	public static void startGameGCD() {
 		System.out.println("Find the greatest common divisor of given numbers.");
 	}

app/src/main/java/hexlet/code/games/Progression.java

@@ -1,6 +1,6 @@
 package hexlet.code.games;
 
-public class Progression {
+public final class Progression {
 	private static int numberOne;
 	private static int numberTwo;
 	private static int sumOfNumbers;
@@ -10,6 +10,10 @@ public class Progression {
 	private static int numberToSkip;
 	private static StringBuilder progressionString = new StringBuilder();
 	private static int correctAnswer;
+	
+	private Progression() {
+		throw new AssertionError("Utility class instantiation prohibited");
+	}
 
 	public static void startGameProgression() {
 		System.out.println("What number is missing in the progression?");