Makes sure utility classes cannot be extended or instantiated

src/main/java/net/knarcraft/bookswithoutborders/utility/BookFormatter.java

@@ -4,10 +4,12 @@ import java.util.List;
 
 /**
  * A class for formatting text to fit books
- *
- * <p>The book formatter</p>
  */
-public class BookFormatter {
+public final class BookFormatter {
+
+    private BookFormatter() {
+
+    }
 
     /**
      * Formats the last page of a set of pages

src/main/java/net/knarcraft/bookswithoutborders/utility/EncryptionHelper.java

@@ -20,7 +20,14 @@ import static net.knarcraft.bookswithoutborders.BooksWithoutBordersSettings.getS
 import static net.knarcraft.bookswithoutborders.utility.InputCleaningHelper.cleanString;
 import static net.knarcraft.bookswithoutborders.utility.InputCleaningHelper.fixName;
 
-public class EncryptionHelper {
+/**
+ * Helper class for book encryption
+ */
+public final class EncryptionHelper {
+
+    private EncryptionHelper() {
+
+    }
 
     /**
      * Transforms a string key/password into its numerical values
@@ -239,7 +246,7 @@ public class EncryptionHelper {
      * @param groupName    <p>The group which should be able to decrypt the book</p>
      * @return <p>The new encrypted metadata for the book, or null if encryption failed</p>
      */
-    protected static BookMeta saveEncryptedBookForGroup(Player player, BookMeta bookMetadata, String groupName) {
+    private static BookMeta saveEncryptedBookForGroup(Player player, BookMeta bookMetadata, String groupName) {
         String path = getBookFolder() + "Encrypted" + getSlash() + cleanString(groupName) + getSlash();
         File dirTest = new File(path);
         //Creates group dir
@@ -294,7 +301,7 @@ public class EncryptionHelper {
      * @param key          <p>The key to use for encryption</p>
      * @return <p>The new encrypted metadata for the book, or null if encryption failed</p>
      */
-    protected static Boolean saveEncryptedBook(Player player, BookMeta bookMetaData, String key) {
+    private static Boolean saveEncryptedBook(Player player, BookMeta bookMetaData, String key) {
         String path = getBookFolder() + "Encrypted" + getSlash();
         String fileName = (!bookMetaData.hasTitle()) ? "Untitled," + player.getName() :
                 bookMetaData.getTitle() + BooksWithoutBorders.titleAuthorSeparator + bookMetaData.getAuthor();

src/main/java/net/knarcraft/bookswithoutborders/utility/FileHelper.java

@@ -9,7 +9,14 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Pattern;
 
-public class FileHelper {
+/**
+ * Helper class for dealing with files
+ */
+public final class FileHelper {
+
+    private FileHelper() {
+
+    }
 
     /**
      * Checks if a file path points to an actual book

src/main/java/net/knarcraft/bookswithoutborders/utility/InputCleaningHelper.java

@@ -3,7 +3,14 @@ package net.knarcraft.bookswithoutborders.utility;
 import java.util.ArrayList;
 import java.util.List;
 
-public class InputCleaningHelper {
+/**
+ * Helper class for cleaning input and names
+ */
+public final class InputCleaningHelper {
+
+    private InputCleaningHelper() {
+
+    }
 
     /**
      * Removes null and empty items from a list

src/main/java/net/knarcraft/bookswithoutborders/utility/InventoryHelper.java

@@ -11,7 +11,11 @@ import org.bukkit.inventory.meta.BookMeta;
 /**
  * The inventory helper mainly helps with getting and setting books
  */
-public class InventoryHelper {
+public final class InventoryHelper {
+
+    private InventoryHelper() {
+
+    }
 
     /**
      * Gets the book the holder is playing