Prevent instantiating utility classes

src/main/java/wtf/beatrice/hidekobot/Cache.java

@@ -22,6 +22,10 @@ import java.util.concurrent.ScheduledExecutorService;
 public class Cache
 {
 
+    private Cache() {
+        throw new IllegalStateException("Utility class");
+    }
+
 
     // todo: make this compatible with the message listener's regex
     private static final String BOT_PREFIX = "hideko";

src/main/java/wtf/beatrice/hidekobot/commands/base/Alias.java

@@ -6,6 +6,10 @@ import java.util.LinkedList;
 
 public class Alias
 {
+    private Alias() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static String generateNiceAliases(MessageCommand command)
     {
         LinkedList<String> aliases = command.getCommandLabels();

src/main/java/wtf/beatrice/hidekobot/commands/base/BotInfo.java

@@ -13,6 +13,10 @@ import java.util.List;
 
 public class BotInfo
 {
+    private BotInfo() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static MessageEmbed generateEmbed(List<String> commandLabels)
     {
         EmbedBuilder embedBuilder = new EmbedBuilder();

src/main/java/wtf/beatrice/hidekobot/commands/base/ClearChat.java

@@ -14,6 +14,9 @@ import java.util.List;
 
 public class ClearChat
 {
+    private ClearChat() {
+        throw new IllegalStateException("Utility class");
+    }
 
     public static String getLabel() {
         return "clear";

src/main/java/wtf/beatrice/hidekobot/commands/base/CoinFlip.java

@@ -14,6 +14,9 @@ import java.util.List;
 public class CoinFlip
 {
 
+    private CoinFlip() {
+        throw new IllegalStateException("Utility class");
+    }
 
     public static Button getReflipButton() {
         return Button.primary("coinflip_reflip", "Flip again")

src/main/java/wtf/beatrice/hidekobot/commands/base/DiceRoll.java

@@ -14,6 +14,11 @@ import java.util.UUID;
 
 public class DiceRoll
 {
+
+    private DiceRoll() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static MessageResponse buildResponse(User author, String[] args)
     {
         LinkedHashMap<Dice, Integer> dicesToRoll = new LinkedHashMap<>();

src/main/java/wtf/beatrice/hidekobot/commands/base/Invite.java

@@ -10,6 +10,10 @@ import wtf.beatrice.hidekobot.HidekoBot;
 public class Invite
 {
 
+    private Invite() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static MessageEmbed generateEmbed()
     {
         EmbedBuilder embedBuilder = new EmbedBuilder();

src/main/java/wtf/beatrice/hidekobot/commands/base/LoveCalculator.java

@@ -10,6 +10,11 @@ import java.util.concurrent.TimeUnit;
 
 public class LoveCalculator
 {
+
+    private LoveCalculator() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static MessageEmbed buildEmbedAndCacheResult(User author, User user1, User user2)
     {
         String userId1 = user1.getId();

src/main/java/wtf/beatrice/hidekobot/commands/base/MagicBall.java

@@ -14,6 +14,10 @@ import java.util.List;
 public class MagicBall
 {
 
+    private MagicBall() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static LinkedList<String> getLabels()
     {
         return new LinkedList<>(Arrays.asList("8ball", "8b", "eightball", "magicball"));

src/main/java/wtf/beatrice/hidekobot/commands/base/ProfileImage.java

@@ -8,6 +8,11 @@ import wtf.beatrice.hidekobot.objects.MessageResponse;
 
 public class ProfileImage
 {
+
+    private ProfileImage() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static int parseResolution(int resolution)
     {
         int[] acceptedSizes = Cache.getSupportedAvatarResolutions();

src/main/java/wtf/beatrice/hidekobot/commands/base/Say.java

@@ -5,6 +5,10 @@ import net.dv8tion.jda.api.Permission;
 public class Say
 {
 
+    private Say() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static Permission getPermission() {
         return Permission.MESSAGE_MANAGE;
     }

src/main/java/wtf/beatrice/hidekobot/commands/base/Trivia.java

@@ -35,6 +35,11 @@ import java.util.concurrent.TimeUnit;
 
 public class Trivia
 {
+
+    private Trivia() {
+        throw new IllegalStateException("Utility class");
+    }
+
     private static final org.slf4j.Logger LOGGER = LoggerFactory.getLogger(Trivia.class);
     private static final String TRIVIA_API_LINK = "https://opentdb.com/api.php?amount=10&type=multiple&category=";
     private static final String TRIVIA_API_CATEGORIES_LINK = "https://opentdb.com/api_category.php";

src/main/java/wtf/beatrice/hidekobot/commands/base/UrbanDictionary.java

@@ -25,6 +25,10 @@ import java.util.List;
 public class UrbanDictionary
 {
 
+    private UrbanDictionary() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static LinkedList<String> getCommandLabels()
     { return new LinkedList<>(Arrays.asList("urban", "urbandictionary", "ud")); }
 

src/main/java/wtf/beatrice/hidekobot/commands/base/UserPunishment.java

@@ -27,6 +27,10 @@ import java.util.concurrent.TimeUnit;
 public class UserPunishment
 {
 
+    private UserPunishment() {
+        throw new IllegalStateException("Utility class");
+    }
+
     private static final Duration maxTimeoutDuration = Duration.of(28, ChronoUnit.DAYS);
     private static final Duration minTimeoutDuration = Duration.of(30, ChronoUnit.SECONDS);
 

src/main/java/wtf/beatrice/hidekobot/util/CommandUtil.java

@@ -27,6 +27,10 @@ public class CommandUtil
 
     private static final Logger LOGGER = LoggerFactory.getLogger(CommandUtil.class);
 
+    private CommandUtil() {
+        throw new IllegalStateException("Utility class");
+    }
+
     /**
      * Function to delete a message when a user clicks the "delete" button attached to that message.
      * This will check in the database if that user ran the command originally.

src/main/java/wtf/beatrice/hidekobot/util/FormatUtil.java

@@ -12,6 +12,9 @@ import java.util.Arrays;
 public class FormatUtil
 {
 
+    private FormatUtil() {
+        throw new IllegalStateException("Utility class");
+    }
 
     // cosmetic string to print on startup.
     private static final String LOGO = """

src/main/java/wtf/beatrice/hidekobot/util/RandomUtil.java

@@ -10,6 +10,10 @@ import java.util.Random;
 public class RandomUtil
 {
 
+    private RandomUtil() {
+        throw new IllegalStateException("Utility class");
+    }
+
     // the Random instance that we should always use when looking for an RNG based thing.
     // the seed is updated periodically, if the random.org integration is enabled.
     private static Random randomInstance = new SecureRandom();

src/main/java/wtf/beatrice/hidekobot/util/SerializationUtil.java

@@ -10,6 +10,10 @@ import java.util.List;
 public class SerializationUtil
 {
 
+    private SerializationUtil() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static <T> String serializeBase64(List<T> dataList) {
 
         try (ByteArrayOutputStream bo = new ByteArrayOutputStream();