Adds ability to filter books by author

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>net.knarcraft</groupId>
     <artifactId>BooksWithoutBorders</artifactId>
-    <version>1.3.8</version>
+    <version>1.3.9-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <licenses>

src/main/java/net/knarcraft/bookswithoutborders/BooksWithoutBorders.java

@@ -39,12 +39,15 @@ import org.bukkit.inventory.ItemFactory;
 import org.bukkit.plugin.PluginDescriptionFile;
 import org.bukkit.plugin.PluginManager;
 import org.bukkit.plugin.java.JavaPlugin;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.UUID;
 import java.util.logging.Level;
 
@@ -61,6 +64,8 @@ public class BooksWithoutBorders extends JavaPlugin {
     private static ItemFactory itemFactory;
     private static Map<UUID, List<String>> playerBooksList;
     private static List<String> publicBooksList;
+    private static Map<Character, Integer> publicLetterIndex;
+    private static Map<UUID, Map<Character, Integer>> playerLetterIndex;
     private static BooksWithoutBorders booksWithoutBorders;
     private static ConsoleCommandSender consoleSender;
 
@@ -88,28 +93,48 @@ public class BooksWithoutBorders extends JavaPlugin {
             if (!playerBooksList.containsKey(playerUUID)) {
                 List<String> newFiles = BookFileHelper.listFiles(sender, false);
                 playerBooksList.put(playerUUID, newFiles);
+                playerLetterIndex.put(playerUUID, BookFileHelper.populateLetterIndices(newFiles));
             }
-            return playerBooksList.get(playerUUID);
+            return new ArrayList<>(playerBooksList.get(playerUUID));
         } else {
             return new ArrayList<>();
         }
     }
 
+    /**
+     * Gets the letter index map for public books, or a specific player's books
+     *
+     * @param playerIndex <p>The player to get the index for, or null for the public index</p>
+     * @return <p>An index mapping between a character and the first index containing that character</p>
+     */
+    @NotNull
+    public static Map<Character, Integer> getLetterIndex(@Nullable UUID playerIndex) {
+        if (playerIndex == null) {
+            return publicLetterIndex;
+        } else {
+            Map<Character, Integer> letterIndex = playerLetterIndex.get(playerIndex);
+            return Objects.requireNonNullElseGet(letterIndex, HashMap::new);
+        }
+    }
+
     /**
      * Updates available books
      *
      * @param sender       <p>The sender to update books for</p>
      * @param updatePublic <p>Whether to update public books</p>
      */
-    public static void updateBooks(CommandSender sender, boolean updatePublic) {
+    public static void updateBooks(@NotNull CommandSender sender, boolean updatePublic) {
         List<String> newFiles = BookFileHelper.listFiles(sender, updatePublic);
         if (updatePublic) {
             publicBooksList = newFiles;
+            publicLetterIndex = BookFileHelper.populateLetterIndices(newFiles);
         } else if (sender instanceof Player player) {
             playerBooksList.put(player.getUniqueId(), newFiles);
+            playerLetterIndex.put(player.getUniqueId(), BookFileHelper.populateLetterIndices(newFiles));
         }
     }
 
+
     @Override
     public void onEnable() {
         FileConfiguration config = this.getConfig();
@@ -123,8 +148,10 @@ public class BooksWithoutBorders extends JavaPlugin {
         booksWithoutBorders = this;
         consoleSender = this.getServer().getConsoleSender();
         playerBooksList = new HashMap<>();
+        playerLetterIndex = new HashMap<>();
         BooksWithoutBordersConfig.initialize(this);
         publicBooksList = BookFileHelper.listFiles(consoleSender, true);
+        publicLetterIndex = BookFileHelper.populateLetterIndices(publicBooksList);
 
         PluginManager pluginManager = this.getServer().getPluginManager();
 

src/main/java/net/knarcraft/bookswithoutborders/command/CommandDelete.java

@@ -1,6 +1,7 @@
 package net.knarcraft.bookswithoutborders.command;
 
 import net.knarcraft.bookswithoutborders.BooksWithoutBorders;
+import net.knarcraft.bookswithoutborders.gui.PagedBookIndex;
 import net.knarcraft.bookswithoutborders.state.BookDirectory;
 import net.knarcraft.bookswithoutborders.utility.BookFileHelper;
 import net.knarcraft.bookswithoutborders.utility.BookHelper;
@@ -21,34 +22,34 @@ import java.util.List;
 public class CommandDelete implements TabExecutor {
 
     @Override
-    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] args) {
+    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] arguments) {
         if (!(sender instanceof Player)) {
             BooksWithoutBorders.sendErrorMessage(sender, "This command can only be used by a player!");
             return false;
         }
 
-        return deleteBook(sender, args, false);
+        return deleteBook(sender, arguments, false);
     }
 
     /**
      * Deletes a book
      *
      * @param sender       <p>The sender trying to delete the book</p>
-     * @param args         <p>The arguments given</p>
+     * @param arguments    <p>The arguments given</p>
      * @param deletePublic <p>Whether to delete a public book</p>
      * @return <p>True if the book was deleted successfully</p>
      */
-    boolean deleteBook(CommandSender sender, String[] args, boolean deletePublic) {
-        //List deletable files
-        if (args.length == 0) {
-            BookFileHelper.printBooks(sender, deletePublic);
+    boolean deleteBook(@NotNull CommandSender sender, @NotNull String[] arguments, boolean deletePublic) {
+        String command = deletePublic ? "deletepublicbook" : "deletebook";
+        if (PagedBookIndex.displayPage(arguments, sender, deletePublic, command)) {
             return true;
         }
+        
         //Delete the file
-        if (args.length == 1) {
+        if (arguments.length == 1) {
             List<String> availableBooks = BooksWithoutBorders.getAvailableBooks(sender, deletePublic);
             if (!availableBooks.isEmpty()) {
-                performBookDeletion(sender, args[0], deletePublic);
+                performBookDeletion(sender, arguments[0], deletePublic);
                 //Update the book list
                 BooksWithoutBorders.updateBooks(sender, deletePublic);
                 return true;

src/main/java/net/knarcraft/bookswithoutborders/command/CommandDeletePublic.java

@@ -13,8 +13,8 @@ import java.util.List;
 public class CommandDeletePublic extends CommandDelete implements TabExecutor {
 
     @Override
-    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, String[] args) {
-        return deleteBook(sender, args, true);
+    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, String[] arguments) {
+        return deleteBook(sender, arguments, true);
     }
 
     @Override

src/main/java/net/knarcraft/bookswithoutborders/command/CommandGive.java

@@ -1,7 +1,7 @@
 package net.knarcraft.bookswithoutborders.command;
 
 import net.knarcraft.bookswithoutborders.BooksWithoutBorders;
-import net.knarcraft.bookswithoutborders.utility.BookFileHelper;
+import net.knarcraft.bookswithoutborders.gui.PagedBookIndex;
 import net.knarcraft.bookswithoutborders.utility.BookLoader;
 import net.knarcraft.bookswithoutborders.utility.InputCleaningHelper;
 import net.knarcraft.bookswithoutborders.utility.TabCompletionTypeHelper;
@@ -25,48 +25,48 @@ public class CommandGive implements TabExecutor {
     private final BooksWithoutBorders booksWithoutBorders = BooksWithoutBorders.getInstance();
 
     @Override
-    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] args) {
+    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] arguments) {
         if (!(sender instanceof Player)) {
             BooksWithoutBorders.sendErrorMessage(sender, "This command can only be used by a player!");
             return false;
         }
 
-        return giveBook(sender, args, false, "player");
+        return giveBook(sender, arguments, false, "player");
     }
 
     /**
      * Gives a book to another player
      *
      * @param sender     <p>The sender trying to give a book</p>
-     * @param args       <p>The arguments given</p>
+     * @param arguments  <p>The arguments given</p>
      * @param givePublic <p>Whether to give a public book</p>
      * @param folder     <p>The folder containing the book to load</p>
      * @return <p>True if the book was given successfully</p>
      */
-    boolean giveBook(CommandSender sender, String[] args, boolean givePublic, String folder) {
-        if (args.length == 1 || args.length > 4) {
+    boolean giveBook(@NotNull CommandSender sender, String[] arguments, boolean givePublic, String folder) {
+        String command = givePublic ? "givepublicbook" : "givebook";
+        if (PagedBookIndex.displayPage(arguments, sender, givePublic, command)) {
+            return true;
+        }
+
+        if (arguments.length == 1 || arguments.length > 4) {
             BooksWithoutBorders.sendErrorMessage(sender, "Incorrect number of arguments for this command!");
             return false;
         }
 
-        if (args.length == 0) {
-            BookFileHelper.printBooks(sender, givePublic);
-            return true;
-        }
-
         //Organize and parse input
-        String bookIdentifier = args[0];
-        String receivingPlayerName = args[1];
+        String bookIdentifier = arguments[0];
+        String receivingPlayerName = arguments[1];
         String copies = "1";
         String isSigned = "true";
-        if (args.length == 4) {
-            copies = args[2];
-            isSigned = args[3];
-        } else if (args.length == 3) {
-            if (args[2].equalsIgnoreCase("true") || args[2].equalsIgnoreCase("false")) {
-                isSigned = args[2];
+        if (arguments.length == 4) {
+            copies = arguments[2];
+            isSigned = arguments[3];
+        } else if (arguments.length == 3) {
+            if (arguments[2].equalsIgnoreCase("true") || arguments[2].equalsIgnoreCase("false")) {
+                isSigned = arguments[2];
             } else {
-                copies = args[2];
+                copies = arguments[2];
             }
         }
 

src/main/java/net/knarcraft/bookswithoutborders/command/CommandGivePublic.java

@@ -13,8 +13,8 @@ import java.util.List;
 public class CommandGivePublic extends CommandGive implements TabExecutor {
 
     @Override
-    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, String[] args) {
-        return giveBook(sender, args, true, "public");
+    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, String[] arguments) {
+        return giveBook(sender, arguments, true, "public");
     }
 
     @Override

src/main/java/net/knarcraft/bookswithoutborders/command/CommandLoad.java

@@ -1,7 +1,7 @@
 package net.knarcraft.bookswithoutborders.command;
 
 import net.knarcraft.bookswithoutborders.BooksWithoutBorders;
-import net.knarcraft.bookswithoutborders.utility.BookFileHelper;
+import net.knarcraft.bookswithoutborders.gui.PagedBookIndex;
 import net.knarcraft.bookswithoutborders.utility.BookLoader;
 import net.knarcraft.bookswithoutborders.utility.InputCleaningHelper;
 import net.knarcraft.bookswithoutborders.utility.TabCompletionTypeHelper;
@@ -22,20 +22,21 @@ import java.util.List;
 public class CommandLoad implements TabExecutor {
 
     @Override
-    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] args) {
-        return loadBook(sender, args, "player", false);
+    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] arguments) {
+        return loadBook(sender, arguments, "player", false);
     }
 
     /**
      * Loads a stored book
      *
      * @param sender     <p>The sender asking to load the book</p>
-     * @param args       <p>The arguments given</p>
+     * @param arguments  <p>The arguments given</p>
      * @param directory  <p>The directory to load from (public/player)</p>
      * @param loadPublic <p>Whether to list public files as loadable</p>
      * @return <p>True if the book was loaded successfully</p>
      */
-    public boolean loadBook(CommandSender sender, String[] args, String directory, boolean loadPublic) {
+    public boolean loadBook(@NotNull CommandSender sender, @NotNull String[] arguments, @NotNull String directory,
+                            boolean loadPublic) {
         if (!(sender instanceof Player player)) {
             BooksWithoutBorders.sendErrorMessage(sender, "This command can only be used by a player!");
             return false;
@@ -46,26 +47,25 @@ public class CommandLoad implements TabExecutor {
             return false;
         }
 
-        int argumentCount = args.length;
+        int argumentCount = arguments.length;
 
-        //Show books available to the player
-        if (argumentCount == 0) {
-            BookFileHelper.printBooks(sender, loadPublic);
+        String command = loadPublic ? "loadpublicbook" : "loadbook";
+        if (PagedBookIndex.displayPage(arguments, sender, loadPublic, command)) {
             return true;
         }
 
         //Organize and parse input
-        String bookIdentifier = args[0];
+        String bookIdentifier = arguments[0];
         String copies = "1";
         String isSigned = "true";
-        if (args.length == 3) {
-            copies = args[1];
-            isSigned = args[2];
-        } else if (args.length == 2) {
-            if (args[1].equalsIgnoreCase("true") || args[1].equalsIgnoreCase("false")) {
-                isSigned = args[1];
+        if (argumentCount == 3) {
+            copies = arguments[1];
+            isSigned = arguments[2];
+        } else if (argumentCount == 2) {
+            if (arguments[1].equalsIgnoreCase("true") || arguments[1].equalsIgnoreCase("false")) {
+                isSigned = arguments[1];
             } else {
-                copies = args[1];
+                copies = arguments[1];
             }
         }
 

src/main/java/net/knarcraft/bookswithoutborders/command/CommandLoadPublic.java

@@ -13,8 +13,8 @@ import java.util.List;
 public class CommandLoadPublic extends CommandLoad implements CommandExecutor {
 
     @Override
-    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, String[] args) {
-        return loadBook(sender, args, "public", true);
+    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, String[] arguments) {
+        return loadBook(sender, arguments, "public", true);
     }
 
     @Override

src/main/java/net/knarcraft/bookswithoutborders/command/CommandSave.java

@@ -8,6 +8,7 @@ import net.knarcraft.bookswithoutborders.utility.BookFileHelper;
 import net.knarcraft.bookswithoutborders.utility.BookHelper;
 import net.knarcraft.bookswithoutborders.utility.BookToFromTextHelper;
 import net.knarcraft.bookswithoutborders.utility.InventoryHelper;
+import net.md_5.bungee.api.ChatColor;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandSender;
 import org.bukkit.command.TabExecutor;
@@ -87,6 +88,11 @@ public class CommandSave implements TabExecutor {
         String savePath = BookHelper.getBookDirectoryPathString(
                 saveToPublicFolder ? BookDirectory.PUBLIC : BookDirectory.PLAYER, player);
 
+        if (savePath == null) {
+            BooksWithoutBorders.sendErrorMessage(player, "Saving Failed! Unable to find the save path!");
+            return;
+        }
+
         //Generate book filename
         String fileName = BookHelper.getBookFile(book, player, saveToPublicFolder);
 
@@ -142,7 +148,7 @@ public class CommandSave implements TabExecutor {
 
             //Update the relevant book list
             BooksWithoutBorders.updateBooks(player, saveToPublicFolder);
-            BooksWithoutBorders.sendSuccessMessage(player, "Book Saved as \"" + fileName + "\"");
+            BooksWithoutBorders.sendSuccessMessage(player, "Book Saved as \"" + fileName + ChatColor.RESET + "\"");
         } catch (IOException exception) {
             BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Unable to save book");
         }

src/main/java/net/knarcraft/bookswithoutborders/gui/AuthorBookIndex.java

@@ -0,0 +1,86 @@
+package net.knarcraft.bookswithoutborders.gui;
+
+import net.knarcraft.bookswithoutborders.BooksWithoutBorders;
+import net.knarcraft.bookswithoutborders.utility.BookFormatter;
+import net.md_5.bungee.api.ChatColor;
+import net.md_5.bungee.api.chat.ClickEvent;
+import net.md_5.bungee.api.chat.ComponentBuilder;
+import net.md_5.bungee.api.chat.HoverEvent;
+import net.md_5.bungee.api.chat.hover.content.Text;
+import org.bukkit.command.CommandSender;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+public class AuthorBookIndex extends BookIndex {
+
+    private final static int booksPerPage = 10;
+
+    /**
+     * Prints the available books
+     *
+     * @param sender     <p>The sender to display the books to</p>
+     * @param listPublic <p>Whether to display public books</p>
+     * @param command    <p>The base command causing this to be called</p>
+     * @param page       <p>The page of the book list to display</p>
+     */
+    public static void printBooks(@NotNull CommandSender sender, boolean listPublic, @NotNull String command, int page,
+                                  @NotNull String authorName) {
+        List<String> availableBooks = BooksWithoutBorders.getAvailableBooks(sender, listPublic);
+        availableBooks.removeIf((bookPath) -> !BookFormatter.stripColor(bookPath.substring(0, bookPath.length() - 4).split(",")[1]).equalsIgnoreCase(authorName));
+
+        int totalPages = (int) Math.ceil((double) availableBooks.size() / booksPerPage);
+        if (page > totalPages) {
+            sender.sendMessage(ChatColor.GRAY + "No such page");
+        } else {
+            showAuthorBooks(sender, command, page, totalPages, availableBooks, authorName);
+        }
+    }
+
+    /**
+     * Shows a menu listing available books from an author
+     *
+     * @param sender         <p>The sender wanting to see the book menu</p>
+     * @param command        <p>The main command used to trigger display of the book menu</p>
+     * @param page           <p>The currently selected page</p>
+     * @param totalPages     <p>The total amount of pages</p>
+     * @param availableBooks <p>All books available to the sender</p>
+     * @param authorName     <p>The name of the author currently shown</p>
+     */
+    private static void showAuthorBooks(@NotNull CommandSender sender, @NotNull String command, int page,
+                                        int totalPages, @NotNull List<String> availableBooks, @NotNull String authorName) {
+        ComponentBuilder componentBuilder = new ComponentBuilder();
+
+        // Display the list of books, with the next and previous buttons
+        displayPreviousButton(componentBuilder, command + " author" + authorName, page);
+        displayBookList(componentBuilder, command, page, availableBooks);
+        displayNextButton(componentBuilder, command + " author" + authorName, page, totalPages);
+
+        // Display total pages and the manual change page command suggestion
+        componentBuilder.append("   ", ComponentBuilder.FormatRetention.NONE);
+        displayTotalPages(componentBuilder, page, totalPages);
+        componentBuilder.append("   ", ComponentBuilder.FormatRetention.NONE);
+        sender.spigot().sendMessage(componentBuilder.create());
+    }
+
+    /**
+     * Displays the list of books on the current page
+     *
+     * @param componentBuilder <p>The component builder to append to</p>
+     * @param command          <p>The command used for switching pages</p>
+     * @param page             <p>The current page</p>
+     * @param availableBooks   <p>All available books</p>
+     */
+    protected static void displayBookList(@NotNull ComponentBuilder componentBuilder, @NotNull String command, int page,
+                                          @NotNull List<String> availableBooks) {
+        int startIndex = (page - 1) * booksPerPage;
+        for (int bookIndex = startIndex; bookIndex < Math.min(startIndex + booksPerPage, availableBooks.size()); bookIndex++) {
+            componentBuilder.append(getNiceName(availableBooks.get(bookIndex))).color(ChatColor.WHITE).event(
+                    new ClickEvent(ClickEvent.Action.SUGGEST_COMMAND, "/" + command + " " +
+                            availableBooks.get(bookIndex))).event(
+                    new HoverEvent(HoverEvent.Action.SHOW_TEXT, new Text("Select book by path")));
+            componentBuilder.append("\n");
+        }
+    }
+
+}

src/main/java/net/knarcraft/bookswithoutborders/gui/BookIndex.java

@@ -0,0 +1,153 @@
+package net.knarcraft.bookswithoutborders.gui;
+
+import net.knarcraft.bookswithoutborders.utility.InputCleaningHelper;
+import net.md_5.bungee.api.ChatColor;
+import net.md_5.bungee.api.chat.ClickEvent;
+import net.md_5.bungee.api.chat.ComponentBuilder;
+import net.md_5.bungee.api.chat.HoverEvent;
+import net.md_5.bungee.api.chat.hover.content.Text;
+import org.bukkit.command.CommandSender;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Map;
+
+public abstract class BookIndex {
+
+    protected final static int booksPerPage = 10;
+
+    /**
+     * Displays the correct GUI, if specified in the given arguments
+     *
+     * @param arguments    <p>The arguments given by a command sender</p>
+     * @param sender       <p>The sender executing the command</p>
+     * @param selectPublic <p>Whether to display public books, or only those available to the command sender</p>
+     * @param command      <p>The command used for changing pages and making the final selection</p>
+     * @return <p>True if the GUI was displayed</p>
+     */
+    public static boolean displayPage(@NotNull String[] arguments, @NotNull CommandSender sender, boolean selectPublic,
+                                      @NotNull String command) {
+        if (arguments.length == 0) {
+            PagedBookIndex.printBooks(sender, selectPublic, command, 1);
+            return true;
+        } else if (arguments.length == 1) {
+            int page = InputCleaningHelper.parsePageNumber(arguments[0]);
+            if (page > 0) {
+                PagedBookIndex.printBooks(sender, selectPublic, command, page);
+                return true;
+            }
+        } else if (arguments.length == 2) {
+            String author = InputCleaningHelper.parseAuthorSpecifier(arguments[0]);
+            if (author != null) {
+                int page = InputCleaningHelper.parsePageNumber(arguments[1]);
+                if (page > 0) {
+                    AuthorBookIndex.printBooks(sender, selectPublic, command, page, author);
+                }
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Displays the suggestion for manually going to any page
+     *
+     * @param componentBuilder <p>The component builder to append to</p>
+     * @param command          <p>The command used for switching pages</p>
+     * @param page             <p>The current page</p>
+     */
+    protected static void displayPageCommand(@NotNull ComponentBuilder componentBuilder, @NotNull String command, int page) {
+        componentBuilder.append("[Page Command]", ComponentBuilder.FormatRetention.NONE).event(new HoverEvent(
+                HoverEvent.Action.SHOW_TEXT, new Text("/" + command + " page" + page))).event(
+                new ClickEvent(ClickEvent.Action.SUGGEST_COMMAND, "/" + command + " page" + page));
+    }
+
+    /**
+     * Displays the current page and total amount of pages
+     *
+     * @param componentBuilder <p>The component builder to append to</p>
+     * @param page             <p>The current page</p>
+     * @param totalPages       <p>The total amount of pages</p>
+     */
+    protected static void displayTotalPages(@NotNull ComponentBuilder componentBuilder, int page, int totalPages) {
+        componentBuilder.append("Page " + page + " of " + totalPages,
+                ComponentBuilder.FormatRetention.NONE).color(ChatColor.GREEN);
+    }
+
+    /**
+     * Displays the alphabet-based page index
+     *
+     * @param componentBuilder <p>The component builder to append to</p>
+     * @param command          <p>The command used for switching pages</p>
+     * @param firstInstances   <p>The map of where the first index of a letter is found</p>
+     */
+    protected static void displayAlphabetIndex(@NotNull ComponentBuilder componentBuilder,
+                                               @NotNull String command, @NotNull Map<Character, Integer> firstInstances) {
+        for (int characterIndex = 0; characterIndex <= 25; characterIndex++) {
+            char character = (char) ('a' + characterIndex);
+            if (firstInstances.containsKey(character)) {
+                int pageIndex = (firstInstances.get(character) / booksPerPage) + 1;
+                componentBuilder.append(character + "").color(
+                        ChatColor.AQUA).event(new ClickEvent(ClickEvent.Action.RUN_COMMAND,
+                        "/" + command + " page" + pageIndex)).event(new HoverEvent(
+                        HoverEvent.Action.SHOW_TEXT, new Text("To page " + pageIndex)));
+            } else {
+                componentBuilder.append(character + "", ComponentBuilder.FormatRetention.NONE).color(ChatColor.GRAY);
+            }
+        }
+        componentBuilder.append("\n");
+    }
+
+    /**
+     * Displays the previous page button
+     *
+     * @param componentBuilder <p>The component builder to append to</p>
+     * @param command          <p>The command used for switching pages</p>
+     * @param page             <p>The current page</p>
+     */
+    protected static void displayPreviousButton(@NotNull ComponentBuilder componentBuilder,
+                                                @NotNull String command, int page) {
+        if (page > 1) {
+            String fullCommand = "/" + command + " page" + (page - 1);
+            HoverEvent prevPagePreview = new HoverEvent(HoverEvent.Action.SHOW_TEXT, new Text("To page " + (page - 1)));
+            ClickEvent prevPageClick = new ClickEvent(ClickEvent.Action.RUN_COMMAND, fullCommand);
+            componentBuilder.append("Previous [<]", ComponentBuilder.FormatRetention.NONE).event(prevPagePreview).event(prevPageClick);
+        } else {
+            componentBuilder.append("Previous [<]", ComponentBuilder.FormatRetention.NONE).color(ChatColor.GRAY);
+        }
+        componentBuilder.append("\n");
+    }
+
+    /**
+     * Displays the next page button
+     *
+     * @param componentBuilder <p>The component builder to append to</p>
+     * @param command          <p>The command used for switching pages</p>
+     * @param page             <p>The current page</p>
+     * @param totalPages       <p>The total amount of pages</p>
+     */
+    protected static void displayNextButton(@NotNull ComponentBuilder componentBuilder,
+                                            @NotNull String command, int page, int totalPages) {
+        if (page < totalPages) {
+            String fullCommand = "/" + command + " page" + (page + 1);
+            HoverEvent nextPagePreview = new HoverEvent(HoverEvent.Action.SHOW_TEXT, new Text("To page " + (page + 1)));
+            ClickEvent nextPageClick = new ClickEvent(ClickEvent.Action.RUN_COMMAND, fullCommand);
+            componentBuilder.append("Next [>]", ComponentBuilder.FormatRetention.NONE).event(nextPagePreview).event(nextPageClick);
+        } else {
+            componentBuilder.append("Next [>]", ComponentBuilder.FormatRetention.NONE).color(ChatColor.GRAY);
+        }
+    }
+
+    /**
+     * Gets a nice name from a book's path
+     *
+     * @param bookPath <p>The path of a book</p>
+     * @return <p>The prettified book name</p>
+     */
+    @NotNull
+    protected static String getNiceName(@NotNull String bookPath) {
+        bookPath = ChatColor.translateAlternateColorCodes('&', bookPath.substring(0, bookPath.length() - 4));
+        String[] parts = bookPath.split(",");
+        return parts[0].replace("_", " ") + ChatColor.RESET + " by " + parts[1] + ChatColor.RESET;
+    }
+
+}

src/main/java/net/knarcraft/bookswithoutborders/gui/PagedBookIndex.java

@@ -0,0 +1,115 @@
+package net.knarcraft.bookswithoutborders.gui;
+
+import net.knarcraft.bookswithoutborders.BooksWithoutBorders;
+import net.knarcraft.bookswithoutborders.utility.BookFormatter;
+import net.md_5.bungee.api.ChatColor;
+import net.md_5.bungee.api.chat.ClickEvent;
+import net.md_5.bungee.api.chat.ComponentBuilder;
+import net.md_5.bungee.api.chat.HoverEvent;
+import net.md_5.bungee.api.chat.hover.content.Text;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * A class for displaying a paged index of all available books
+ */
+public class PagedBookIndex extends BookIndex {
+
+    /**
+     * Prints the available books
+     *
+     * @param sender     <p>The sender to display the books to</p>
+     * @param listPublic <p>Whether to display public books</p>
+     * @param command    <p>The base command causing this to be called</p>
+     * @param page       <p>The page of the book list to display</p>
+     */
+    public static void printBooks(@NotNull CommandSender sender, boolean listPublic, @NotNull String command, int page) {
+        List<String> availableBooks = BooksWithoutBorders.getAvailableBooks(sender, listPublic);
+
+        Map<Character, Integer> firstInstances;
+        if (listPublic) {
+            firstInstances = BooksWithoutBorders.getLetterIndex(null);
+        } else if (sender instanceof Player player) {
+            firstInstances = BooksWithoutBorders.getLetterIndex(player.getUniqueId());
+        } else {
+            firstInstances = new HashMap<>();
+        }
+
+        int totalPages = (int) Math.ceil((double) availableBooks.size() / booksPerPage);
+        if (page > totalPages) {
+            sender.sendMessage(ChatColor.GRAY + "No such page");
+        } else {
+            showBookMenu(sender, command, page, totalPages, availableBooks, firstInstances);
+        }
+    }
+
+    /**
+     * Shows a menu listing available books
+     *
+     * @param sender         <p>The sender wanting to see the book menu</p>
+     * @param command        <p>The main command used to trigger display of the book menu</p>
+     * @param page           <p>The currently selected page</p>
+     * @param totalPages     <p>The total amount of pages</p>
+     * @param availableBooks <p>All books available to the sender</p>
+     * @param firstInstances <p>The map between a character, and the index of the first instance of that character in the book list</p>
+     */
+    private static void showBookMenu(@NotNull CommandSender sender, @NotNull String command, int page,
+                                     int totalPages, @NotNull List<String> availableBooks,
+                                     @NotNull Map<Character, Integer> firstInstances) {
+        ComponentBuilder componentBuilder = new ComponentBuilder();
+
+        // Display the alphabet index as the header
+        displayAlphabetIndex(componentBuilder, command, firstInstances);
+
+        // Display the list of books, with the next and previous buttons
+        displayPreviousButton(componentBuilder, command, page);
+        displayBookList(componentBuilder, command, page, availableBooks);
+        displayNextButton(componentBuilder, command, page, totalPages);
+
+        // Display total pages and the manual change page command suggestion
+        componentBuilder.append("   ", ComponentBuilder.FormatRetention.NONE);
+        displayTotalPages(componentBuilder, page, totalPages);
+        componentBuilder.append("   ", ComponentBuilder.FormatRetention.NONE);
+        displayPageCommand(componentBuilder, command, page);
+        sender.spigot().sendMessage(componentBuilder.create());
+    }
+
+    /**
+     * Displays the list of books on the current page
+     *
+     * @param componentBuilder <p>The component builder to append to</p>
+     * @param command          <p>The command used for switching pages</p>
+     * @param page             <p>The current page</p>
+     * @param availableBooks   <p>All available books</p>
+     */
+    protected static void displayBookList(@NotNull ComponentBuilder componentBuilder, @NotNull String command, int page,
+                                          @NotNull List<String> availableBooks) {
+        int startIndex = (page - 1) * booksPerPage;
+        for (int bookIndex = startIndex; bookIndex < Math.min(startIndex + booksPerPage, availableBooks.size()); bookIndex++) {
+            componentBuilder.append("[" + (bookIndex + 1) + "]").color(ChatColor.GOLD).event(
+                    new ClickEvent(ClickEvent.Action.SUGGEST_COMMAND, "/" + command + " " +
+                            (bookIndex + 1))).event(new HoverEvent(HoverEvent.Action.SHOW_TEXT,
+                    new Text("Select book by index")));
+
+            componentBuilder.append(" ", ComponentBuilder.FormatRetention.NONE);
+
+            String[] parts = getNiceName(availableBooks.get(bookIndex)).split(" by ");
+            componentBuilder.append(parts[0]).color(ChatColor.WHITE).event(
+                    new ClickEvent(ClickEvent.Action.SUGGEST_COMMAND, "/" + command + " " +
+                            availableBooks.get(bookIndex))).event(
+                    new HoverEvent(HoverEvent.Action.SHOW_TEXT, new Text("Select book by path")));
+            componentBuilder.append(" by ", ComponentBuilder.FormatRetention.NONE).color(ChatColor.WHITE);
+            componentBuilder.append(parts[1]).color(ChatColor.WHITE).event(
+                    new ClickEvent(ClickEvent.Action.RUN_COMMAND, "/" + command + " author" +
+                            BookFormatter.stripColor(parts[1]) + " page1")).event(
+                    new HoverEvent(HoverEvent.Action.SHOW_TEXT, new Text("Filter by author")));
+            componentBuilder.append("\n");
+        }
+    }
+
+}

src/main/java/net/knarcraft/bookswithoutborders/listener/SignEventListener.java

@@ -4,6 +4,7 @@ import net.knarcraft.bookswithoutborders.BooksWithoutBorders;
 import net.knarcraft.bookswithoutborders.config.BooksWithoutBordersConfig;
 import net.knarcraft.bookswithoutborders.state.EncryptionStyle;
 import net.knarcraft.bookswithoutborders.utility.BookFileHelper;
+import net.knarcraft.bookswithoutborders.utility.BookFormatter;
 import net.knarcraft.bookswithoutborders.utility.BookLoader;
 import net.knarcraft.bookswithoutborders.utility.EncryptionHelper;
 import net.knarcraft.bookswithoutborders.utility.InputCleaningHelper;
@@ -144,7 +145,7 @@ public class SignEventListener implements Listener {
             player.closeInventory();
 
             //Converts user supplied key into integer form
-            String lineText = ChatColor.stripColor(sign.getSide(Side.FRONT).getLine(2));
+            String lineText = BookFormatter.stripColor(sign.getSide(Side.FRONT).getLine(2));
             String key = EncryptionHelper.getNumberKeyFromStringKey(lineText);
 
             ItemStack book = EncryptionHelper.loadEncryptedBook(player, key, false);
@@ -163,7 +164,7 @@ public class SignEventListener implements Listener {
      */
     private ChatColor getSignLine2Color(Sign sign) {
         String line = sign.getSide(Side.FRONT).getLine(2);
-        if (!ChatColor.stripColor(line).equals(line)) {
+        if (!BookFormatter.stripColor(line).equals(line)) {
             return ChatColor.getByChar(sign.getSide(Side.FRONT).getLine(2).substring(1, 2).charAt(0));
         } else {
             return null;
@@ -291,8 +292,8 @@ public class SignEventListener implements Listener {
         boolean mainHand = hand == EquipmentSlot.HAND;
         if (heldItemType == Material.WRITTEN_BOOK) {
             player.closeInventory();
-            eBook = EncryptionHelper.encryptBook(player, mainHand, ChatColor.stripColor(lines[2]),
-                    EncryptionStyle.getFromString(ChatColor.stripColor(lines[3])));
+            eBook = EncryptionHelper.encryptBook(player, mainHand, BookFormatter.stripColor(lines[2]),
+                    EncryptionStyle.getFromString(BookFormatter.stripColor(lines[3])));
             if (eBook != null) {
                 player.getInventory().setItem(hand, eBook);
             }
@@ -306,7 +307,7 @@ public class SignEventListener implements Listener {
      * @param player <p>The player which clicked the sign</p>
      */
     private void giveBook(Sign sign, Player player) {
-        String fileName = ChatColor.stripColor(sign.getSide(Side.FRONT).getLine(2));
+        String fileName = BookFormatter.stripColor(sign.getSide(Side.FRONT).getLine(2));
         boolean isLoadListNumber = false;
 
         try {
@@ -318,7 +319,7 @@ public class SignEventListener implements Listener {
         //Add the third line to the second line for the full filename
         String thirdLine = sign.getSide(Side.FRONT).getLine(3);
         if (!isLoadListNumber && thirdLine.length() >= 2) {
-            fileName += ChatColor.stripColor(thirdLine);
+            fileName += BookFormatter.stripColor(thirdLine);
         }
 
         ItemStack newBook = BookLoader.loadBook(player, fileName, "true", "public");

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

@@ -3,12 +3,16 @@ package net.knarcraft.bookswithoutborders.utility;
 import net.knarcraft.bookswithoutborders.BooksWithoutBorders;
 import net.knarcraft.bookswithoutborders.config.BooksWithoutBordersConfig;
 import net.knarcraft.bookswithoutborders.state.BookDirectory;
-import net.md_5.bungee.api.ChatColor;
 import org.bukkit.command.CommandSender;
+import org.jetbrains.annotations.NotNull;
 
 import java.io.File;
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.regex.Pattern;
 
@@ -102,31 +106,27 @@ public final class BookFileHelper {
     }
 
     /**
-     * Prints the available books
+     * Gets a map between characters, and the first instance of a book's title starting with that character
      *
-     * @param sender     <p>The sender to display the books to</p>
-     * @param listPublic <p>Whether to display public books</p>
+     * @param books <p>The books to look through</p>
+     * @return <p>The map of the first index containing each character</p>
      */
-    public static void printBooks(CommandSender sender, boolean listPublic) {
-        List<String> availableBooks = BooksWithoutBorders.getAvailableBooks(sender, listPublic);
-        BookFileHelper.printFiles(sender, availableBooks);
-    }
+    @NotNull
+    public static Map<Character, Integer> populateLetterIndices(@NotNull List<String> books) {
+        List<Character> firstCharacter = new ArrayList<>(books.size());
+        for (String bookIdentifier : books) {
+            firstCharacter.add(BookFormatter.stripColor(bookIdentifier).toLowerCase().charAt(0));
+        }
 
-    /**
-     * Prints a list of files
-     *
-     * @param sender   <p>The command sender to show the list to</p>
-     * @param fileList <p>The files to list</p>
-     */
-    public static void printFiles(CommandSender sender, List<String> fileList) {
-        BooksWithoutBorders.sendSuccessMessage(sender, "Available Books:");
-        if (fileList == null) {
-            return;
-        }
-        int listSize = fileList.size();
-        for (int fileIndex = 0; fileIndex < listSize; fileIndex++) {
-            sender.sendMessage(ChatColor.GRAY + "[" + (fileIndex + 1) + "] " + fileList.get(fileIndex));
+        Map<Character, Integer> firstEncounter = new HashMap<>();
+        for (int characterIndex = 0; characterIndex <= 25; characterIndex++) {
+            char character = (char) ('a' + characterIndex);
+            int index = Collections.binarySearch(firstCharacter, character);
+            if (index >= 0) {
+                firstEncounter.put(character, index);
+            }
         }
+        return firstEncounter;
     }
 
     /**
@@ -163,6 +163,9 @@ public final class BookFileHelper {
             }
         }
 
+        // Sort the book list
+        Comparator<String> bookComparator = Comparator.naturalOrder();
+        fileList.sort((a, b) -> bookComparator.compare(BookFormatter.stripColor(a), BookFormatter.stripColor(b)));
         return fileList;
     }
 

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

@@ -3,6 +3,7 @@ package net.knarcraft.bookswithoutborders.utility;
 import net.knarcraft.knarlib.property.ColorConversion;
 import net.knarcraft.knarlib.util.ColorHelper;
 import org.bukkit.inventory.meta.BookMeta;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -114,4 +115,15 @@ public final class BookFormatter {
         return bookMeta;
     }
 
+    /**
+     * Strips the color from the given input
+     *
+     * @param input <p>The input to strip</p>
+     * @return <p>The color stripped input</p>
+     */
+    @NotNull
+    public static String stripColor(@NotNull String input) {
+        return ColorHelper.stripColorCodes(input, ColorConversion.RGB);
+    }
+
 }

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

@@ -8,6 +8,8 @@ import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.BookMeta;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
 import java.util.UUID;
@@ -31,7 +33,8 @@ public final class BookHelper {
      * @param author <p>The author string</p>
      * @return <p>The author string, converted if it was a UUID</p>
      */
-    public static String authorFromUUID(String author) {
+    @NotNull
+    public static String authorFromUUID(@NotNull String author) {
         try {
             UUID authorID = UUID.fromString(author);
             Player player = Bukkit.getPlayer(authorID);
@@ -50,7 +53,7 @@ public final class BookHelper {
      * @param sender        <p>The command sender trying to get the directory</p>
      * @return <p>The path of the directory, or null if not possible to get</p>
      */
-    public static File getBookDirectoryPath(BookDirectory bookDirectory, CommandSender sender) {
+    public static File getBookDirectoryPath(@NotNull BookDirectory bookDirectory, @NotNull CommandSender sender) {
         String bookFolderString = getBookDirectoryPathString(bookDirectory, sender);
         if (bookFolderString == null) {
             return null;
@@ -65,7 +68,8 @@ public final class BookHelper {
      * @param sender        <p>The command sender trying to get the directory</p>
      * @return <p>The path of the directory, or null if not possible to get</p>
      */
-    public static String getBookDirectoryPathString(BookDirectory bookDirectory, CommandSender sender) {
+    @Nullable
+    public static String getBookDirectoryPathString(@NotNull BookDirectory bookDirectory, @NotNull CommandSender sender) {
         String folder = null;
         String bookFolder = BooksWithoutBordersConfig.getBookFolder();
         if (bookDirectory == BookDirectory.PUBLIC) {
@@ -81,7 +85,7 @@ public final class BookHelper {
      *
      * @param bookItem <p>The book item to increase the generation of</p>
      */
-    public static void increaseGeneration(ItemStack bookItem) {
+    public static void increaseGeneration(@NotNull ItemStack bookItem) {
         BookMeta bookMeta = (BookMeta) bookItem.getItemMeta();
         if (BooksWithoutBordersConfig.changeGenerationOnCopy() && bookMeta != null) {
             bookMeta.setGeneration(BookHelper.getNextGeneration(bookMeta.getGeneration()));
@@ -98,7 +102,8 @@ public final class BookHelper {
      * @param currentGeneration <p>The current generation of the book</p>
      * @return <p>The next generation of the book</p>
      */
-    public static BookMeta.Generation getNextGeneration(BookMeta.Generation currentGeneration) {
+    @NotNull
+    public static BookMeta.Generation getNextGeneration(@Nullable BookMeta.Generation currentGeneration) {
         if (currentGeneration == null) {
             return BookMeta.Generation.COPY_OF_ORIGINAL;
         }
@@ -116,7 +121,8 @@ public final class BookHelper {
      * @param player <p>The player trying to do something with the book</p>
      * @return <p>The book file</p>
      */
-    public static String getBookFile(BookMeta book, Player player, boolean isPublic) {
+    @NotNull
+    public static String getBookFile(@NotNull BookMeta book, @NotNull Player player, boolean isPublic) {
         String titleAuthorSeparator = BooksWithoutBordersConfig.getTitleAuthorSeparator();
         String bookName;
         if (book.hasTitle()) {
@@ -145,7 +151,7 @@ public final class BookHelper {
      * @param book   <p>The book to check</p>
      * @return <p>True if the player is not the book's author</p>
      */
-    public static boolean isNotAuthor(Player player, BookMeta book) {
+    public static boolean isNotAuthor(@NotNull Player player, @NotNull BookMeta book) {
         if (isAuthor(player.getName(), book.getAuthor())) {
             return false;
         } else {
@@ -162,7 +168,7 @@ public final class BookHelper {
      * @param author     <p>The author to check</p>
      * @return <p>True if the player is the author</p>
      */
-    private static boolean isAuthor(String playerName, String author) {
+    private static boolean isAuthor(@NotNull String playerName, @Nullable String author) {
         playerName = InputCleaningHelper.cleanString(playerName);
         return author != null && playerName.equalsIgnoreCase(InputCleaningHelper.cleanString(author));
     }

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

@@ -9,6 +9,8 @@ import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.BookMeta;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
 import java.util.ArrayList;
@@ -31,7 +33,9 @@ public final class BookLoader {
      * @param directory <p>The directory to save the book in</p>
      * @return <p>The loaded book</p>
      */
-    public static ItemStack loadBook(CommandSender sender, String fileName, String isSigned, String directory) {
+    @Nullable
+    public static ItemStack loadBook(@NotNull CommandSender sender, @NotNull String fileName, @NotNull String isSigned,
+                                     @NotNull String directory) {
         return loadBook(sender, fileName, isSigned, directory, 1);
     }
 
@@ -45,7 +49,9 @@ public final class BookLoader {
      * @param numCopies <p>The number of copies to load</p>
      * @return <p>The loaded book</p>
      */
-    public static ItemStack loadBook(CommandSender sender, String fileName, String isSigned, String directory, int numCopies) {
+    @Nullable
+    public static ItemStack loadBook(@NotNull CommandSender sender, @NotNull String fileName, @NotNull String isSigned,
+                                     @NotNull String directory, int numCopies) {
         BookDirectory bookDirectory = BookDirectory.getFromString(directory);
 
         //Find the filename if a book index is given
@@ -96,8 +102,13 @@ public final class BookLoader {
             book = new ItemStack(Material.WRITABLE_BOOK);
         }
 
+        if (bookMetadata == null) {
+            BooksWithoutBorders.sendErrorMessage(sender, "Unable to create blank book metadata!");
+            return null;
+        }
+
         //Load the book from the given file
-        BookToFromTextHelper.bookFromFile(file, bookMetadata);
+        bookMetadata = BookToFromTextHelper.bookFromFile(file, bookMetadata);
         if (bookMetadata == null) {
             BooksWithoutBorders.sendErrorMessage(sender, "File was blank!!");
             return null;

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

@@ -6,6 +6,8 @@ import net.knarcraft.knarlib.util.FileHelper;
 import org.bukkit.configuration.file.FileConfiguration;
 import org.bukkit.configuration.file.YamlConfiguration;
 import org.bukkit.inventory.meta.BookMeta;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.BufferedReader;
 import java.io.File;
@@ -37,7 +39,7 @@ public final class BookToFromTextHelper {
      * @param bookMetadata <p>Metadata about the book to save</p>
      * @throws IOException <p>If unable to save the book</p>
      */
-    public static void bookToYml(String path, String fileName, BookMeta bookMetadata) throws IOException {
+    public static void bookToYml(@NotNull String path, @NotNull String fileName, @NotNull BookMeta bookMetadata) throws IOException {
         FileConfiguration bookYml = YamlConfiguration.loadConfiguration(new File(path, "blank"));
 
         if (bookMetadata.hasTitle()) {
@@ -58,7 +60,7 @@ public final class BookToFromTextHelper {
             bookYml.set("Lore", bookMetadata.getLore());
         }
 
-        bookYml.save(path + fileName + ".yml");
+        bookYml.save(path + fileName.replace("§", "&") + ".yml");
     }
 
     /**
@@ -68,7 +70,8 @@ public final class BookToFromTextHelper {
      * @param bookMetadata <p>The book metadata to use for saving the book</p>
      * @return <p>The book metadata of the loaded book</p>
      */
-    public static BookMeta bookFromFile(File file, BookMeta bookMetadata) {
+    @Nullable
+    public static BookMeta bookFromFile(@NotNull File file, @NotNull BookMeta bookMetadata) {
         if (file.getName().endsWith(".txt")) {
             return bookFromTXT(file.getName(), file, bookMetadata);
         } else if (file.getName().endsWith(".yml")) {
@@ -86,8 +89,8 @@ public final class BookToFromTextHelper {
      * @param bookMetadata <p>Metadata about the book to save</p>
      * @throws IOException <p>If unable to save the book</p>
      */
-    public static void bookToTXT(String folderPath, String fileName, BookMeta bookMetadata) throws IOException {
-        FileWriter fileWriter = new FileWriter(folderPath + fileName + ".txt", StandardCharsets.UTF_8);
+    public static void bookToTXT(@NotNull String folderPath, @NotNull String fileName, @NotNull BookMeta bookMetadata) throws IOException {
+        FileWriter fileWriter = new FileWriter(folderPath + fileName.replace("§", "&") + ".txt", StandardCharsets.UTF_8);
         PrintWriter printWriter = new PrintWriter(fileWriter);
         List<String> pages = bookMetadata.getPages();
 
@@ -112,7 +115,8 @@ public final class BookToFromTextHelper {
      * @param bookMetadata <p>Metadata which will be altered with the book's contents</p>
      * @return <p>Metadata for the loaded book</p>
      */
-    private static BookMeta bookFromYml(File file, BookMeta bookMetadata) {
+    @Nullable
+    private static BookMeta bookFromYml(@NotNull File file, @NotNull BookMeta bookMetadata) {
         try {
             FileConfiguration bookYml = YamlConfiguration.loadConfiguration(file);
 
@@ -135,7 +139,8 @@ public final class BookToFromTextHelper {
      * @param bookMetadata <p>Metadata which will be altered with the book's contents</p>
      * @return <p>Metadata for the loaded book</p>
      */
-    private static BookMeta bookFromTXT(String fileName, File file, BookMeta bookMetadata) {
+    @Nullable
+    private static BookMeta bookFromTXT(@NotNull String fileName, @NotNull File file, @NotNull BookMeta bookMetadata) {
         String author;
         String title;
         String titleAuthorSeparator = BooksWithoutBordersConfig.getTitleAuthorSeparator();
@@ -188,7 +193,8 @@ public final class BookToFromTextHelper {
      * @return <p>A string list where each string is the text on one page</p>
      * @throws IOException <p>If unable to read from the file</p>
      */
-    private static List<String> readTextFile(File file) throws IOException {
+    @Nullable
+    private static List<String> readTextFile(@NotNull File file) throws IOException {
         List<String> rawPages = new ArrayList<>();
         BufferedReader bufferedReader = FileHelper.getBufferedReaderFromInputStream(new FileInputStream(file));
 

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

@@ -1,7 +1,12 @@
 package net.knarcraft.bookswithoutborders.utility;
 
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
 import java.util.ArrayList;
 import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /**
  * Helper class for cleaning input and names
@@ -58,4 +63,41 @@ public final class InputCleaningHelper {
         return fileName;
     }
 
+    /**
+     * Parses a page number for a string like "page1"
+     *
+     * @param input <p>The input to parse</p>
+     * @return <p>The page number, or 0 if not valid</p>
+     */
+    public static int parsePageNumber(@NotNull String input) {
+        try {
+            Pattern pattern = Pattern.compile("page([0-9])+");
+            Matcher matcher = pattern.matcher(input);
+            if (matcher.matches()) {
+                return Integer.parseInt(matcher.group(1));
+            } else {
+                return 0;
+            }
+        } catch (NumberFormatException exception) {
+            return 0;
+        }
+    }
+
+    /**
+     * Parses an author specifier given in a command
+     *
+     * @param input <p>The input to parse</p>
+     * @return <p>The author name, or null if not an author specifier</p>
+     */
+    @Nullable
+    public static String parseAuthorSpecifier(@NotNull String input) {
+        Pattern pattern = Pattern.compile("author([0-9a-zA-Z_]+)");
+        Matcher matcher = pattern.matcher(input);
+        if (matcher.matches()) {
+            return matcher.group(1);
+        } else {
+            return null;
+        }
+    }
+
 }