Fixes some warnings

pom.xml

@@ -143,7 +143,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.13.1</version>
+            <version>4.13.2</version>
             <scope>test</scope>
         </dependency>
     </dependencies>

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

@@ -46,6 +46,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
+import java.util.logging.Level;
 
 import static net.knarcraft.bookswithoutborders.config.BooksWithoutBordersConfig.getBookFolder;
 import static net.knarcraft.bookswithoutborders.config.BooksWithoutBordersConfig.getErrorColor;
@@ -244,8 +245,8 @@ public class BooksWithoutBorders extends JavaPlugin {
                     sendErrorMessage(consoleSender, "Saving failed! Aborting...");
                     return false;
                 }
-            } catch (Exception e) {
+            } catch (Exception exception) {
-                e.printStackTrace();
+                BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Unable to create necessary folders");
                 return false;
             }
         }
@@ -255,8 +256,8 @@ public class BooksWithoutBorders extends JavaPlugin {
                     sendErrorMessage(consoleSender, "Saving failed! Aborting...");
                     return false;
                 }
-            } catch (Exception e) {
+            } catch (Exception exception) {
-                e.printStackTrace();
+                BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Unable to create necessary folders");
                 return false;
             }
         }

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

@@ -20,6 +20,7 @@ import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.logging.Level;
 
 import static net.knarcraft.bookswithoutborders.config.BooksWithoutBordersConfig.getCommandColor;
 import static net.knarcraft.bookswithoutborders.config.BooksWithoutBordersConfig.getErrorColor;
@@ -142,8 +143,8 @@ public class CommandSave implements TabExecutor {
             //Update the relevant book list
             BooksWithoutBorders.updateBooks(player, saveToPublicFolder);
             BooksWithoutBorders.sendSuccessMessage(player, "Book Saved as \"" + fileName + "\"");
-        } catch (IOException e) {
+        } catch (IOException exception) {
-            e.printStackTrace();
+            BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Unable to save book");
         }
 
     }

src/main/java/net/knarcraft/bookswithoutborders/config/BooksWithoutBordersConfig.java

@@ -7,6 +7,7 @@ import org.bukkit.Material;
 import org.bukkit.command.ConsoleCommandSender;
 import org.bukkit.configuration.Configuration;
 
+import java.nio.file.FileSystems;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -22,7 +23,7 @@ public class BooksWithoutBordersConfig {
     private static final ChatColor errorColor = ChatColor.RED;
     private static final ChatColor successColor = ChatColor.GREEN;
     private static final ChatColor commandColor = ChatColor.YELLOW;
-    private static final String SLASH = System.getProperty("file.separator");
+    private static final String SLASH = FileSystems.getDefault().getSeparator();
     private static boolean isInitialized;
     public static String bookFolder;
 

src/main/java/net/knarcraft/bookswithoutborders/encryption/AES.java

@@ -1,5 +1,7 @@
 package net.knarcraft.bookswithoutborders.encryption;
 
+import net.knarcraft.bookswithoutborders.BooksWithoutBorders;
+
 import javax.crypto.BadPaddingException;
 import javax.crypto.Cipher;
 import javax.crypto.IllegalBlockSizeException;
@@ -15,6 +17,7 @@ import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 import java.security.spec.InvalidKeySpecException;
 import java.util.Base64;
+import java.util.logging.Level;
 
 /**
  * This class represents and AES encryptor/decryptor
@@ -66,16 +69,16 @@ public class AES {
         //Initialize cipher
         try {
             aes.init(mode, secretKeySpec, ivParameterSpec);
-        } catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
+        } catch (InvalidKeyException | InvalidAlgorithmParameterException exception) {
-            e.printStackTrace();
+            BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Invalid AES input given!");
             return null;
         }
         //Perform encryption/decryption and output result
         try {
             byte[] output = aes.doFinal(getInputBytes(input, encrypt));
             return createResult(output, encrypt);
-        } catch (IllegalBlockSizeException | BadPaddingException e) {
+        } catch (IllegalBlockSizeException | BadPaddingException exception) {
-            e.printStackTrace();
+            BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Invalid AES block size or padding");
             return null;
         }
     }
@@ -131,8 +134,8 @@ public class AES {
         Cipher aes;
         try {
             aes = Cipher.getInstance("AES/CBC/PKCS5Padding");
-        } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
+        } catch (NoSuchAlgorithmException | NoSuchPaddingException exception) {
-            e.printStackTrace();
+            BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Invalid AES algorithm or padding");
             return null;
         }
         return aes;
@@ -149,15 +152,15 @@ public class AES {
         SecretKeyFactory keyFactory;
         try {
             keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
-        } catch (NoSuchAlgorithmException e) {
+        } catch (NoSuchAlgorithmException exception) {
-            e.printStackTrace();
+            BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Invalid AES algorithm");
             return null;
         }
         SecretKey tmp;
         try {
             tmp = keyFactory.generateSecret(spec);
-        } catch (InvalidKeySpecException e) {
+        } catch (InvalidKeySpecException exception) {
-            e.printStackTrace();
+            BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Invalid AES key specification");
             return null;
         }
         return new SecretKeySpec(tmp.getEncoded(), "AES");

src/main/java/net/knarcraft/bookswithoutborders/encryption/GenenCrypt.java

@@ -33,7 +33,7 @@ public class GenenCrypt {
             for (int j = 0; j < 4; j++) {
                 for (int k = 0; k < 4; k++) {
                     for (int l = 0; l < 4; l++) {
-                        originalCodonList.add("" + bases[i] + bases[j] + bases[k] + bases[l]);
+                        originalCodonList.add(bases[i] + bases[j] + bases[k] + bases[l]);
                     }
                 }
             }
@@ -49,7 +49,7 @@ public class GenenCrypt {
 
         // use the random number generator and the originalCodonList to make a shuffled list
         ArrayList<String> shuffledCodonList = new ArrayList<>();
-        while (originalCodonList.size() > 0) {
+        while (!originalCodonList.isEmpty()) {
             int index = ranGen.nextInt(originalCodonList.size());
             shuffledCodonList.add(originalCodonList.get(index));
             originalCodonList.remove(index);

src/main/java/net/knarcraft/bookswithoutborders/encryption/SubstitutionCipher.java

@@ -19,7 +19,7 @@ public class SubstitutionCipher {
     // original message is offset by
     public String encrypt(String in, String key) {
         StringBuilder output = new StringBuilder();
-        if (key != null && key.length() > 0) {
+        if (key != null && !key.isEmpty()) {
             StringTokenizer tokenizer = new StringTokenizer(key, ", "); // tokenizes the key
             // converts each number in the key to an integer and adds to an array
             int[] offsetArray = new int[tokenizer.countTokens()];
@@ -55,7 +55,7 @@ public class SubstitutionCipher {
     @SuppressWarnings("unused")
     public String decrypt(String in, String key) {
         StringBuilder output = new StringBuilder();
-        if (key != null && key.length() > 0) {
+        if (key != null && !key.isEmpty()) {
             StringTokenizer tokenizer = new StringTokenizer(key, ", "); // tokenizes the key
             // converts each number in the key to an integer and adds to an array
             int[] offsetArray = new int[tokenizer.countTokens()];

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

@@ -33,7 +33,8 @@ public class BookshelfListener implements Listener {
         Player player = event.getPlayer();
 
         // If left-clicking a chiseled bookshelf and sneaking, display contents
-        if (!event.hasBlock() || !(event.getClickedBlock().getState() instanceof ChiseledBookshelf chiseledBookshelf) ||
+        if (!event.hasBlock() || event.getClickedBlock() == null ||
+                !(event.getClickedBlock().getState() instanceof ChiseledBookshelf chiseledBookshelf) ||
                 event.getAction() != Action.LEFT_CLICK_BLOCK || !player.isSneaking()) {
             return;
         }

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

@@ -57,7 +57,7 @@ public class SignEventListener implements Listener {
 
         //Check if the sign is of a valid type
         if (!((lines[1].equalsIgnoreCase("[Encrypt]") || lines[1].equalsIgnoreCase("[Decrypt]") ||
-                lines[1].equalsIgnoreCase("[Give]")) && lines[2].trim().length() > 0)) {
+                lines[1].equalsIgnoreCase("[Give]")) && !lines[2].trim().isEmpty())) {
             //Mark the second line as invalid
             event.setLine(1, ChatColor.DARK_RED + lines[1]);
             return;

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

@@ -1,5 +1,6 @@
 package net.knarcraft.bookswithoutborders.utility;
 
+import net.knarcraft.bookswithoutborders.BooksWithoutBorders;
 import net.knarcraft.bookswithoutborders.config.BooksWithoutBordersConfig;
 import net.knarcraft.knarlib.util.FileHelper;
 import org.bukkit.configuration.file.FileConfiguration;
@@ -15,6 +16,7 @@ import java.io.PrintWriter;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.logging.Level;
 
 import static net.knarcraft.bookswithoutborders.utility.BookHelper.authorFromUUID;
 import static net.knarcraft.bookswithoutborders.utility.InputCleaningHelper.fixName;
@@ -157,13 +159,13 @@ public final class BookToFromTextHelper {
         List<String> rawPages;
         try {
             rawPages = readTextFile(file);
-        } catch (IOException e) {
+        } catch (IOException exception) {
-            e.printStackTrace();
+            BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Unable to read text file");
             return null;
         }
 
         //Parse the generation from the book data
-        if (rawPages != null && rawPages.size() > 0 && rawPages.get(0).startsWith("Generation:")) {
+        if (rawPages != null && !rawPages.isEmpty() && rawPages.get(0).startsWith("Generation:")) {
             bookMetadata.setGeneration(BookMeta.Generation.valueOf(rawPages.get(0).split(":")[1]));
             rawPages.remove(0);
         }

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

@@ -16,6 +16,7 @@ import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.logging.Level;
 
 import static net.knarcraft.bookswithoutborders.config.BooksWithoutBordersConfig.getBookFolder;
 import static net.knarcraft.bookswithoutborders.config.BooksWithoutBordersConfig.getSlash;
@@ -255,8 +256,8 @@ public final class EncryptionHelper {
                     BooksWithoutBorders.sendErrorMessage(BooksWithoutBorders.getConsoleSender(), "Unable to create encryption group folder!");
                     return null;
                 }
-            } catch (Exception e) {
+            } catch (Exception exception) {
-                e.printStackTrace();
+                BooksWithoutBorders.getInstance().getLogger().log(Level.SEVERE, "Unable to save group encrypted book");
                 return null;
             }
         }
@@ -279,8 +280,7 @@ public final class EncryptionHelper {
         if (!file.isFile()) {
             try {
                 BookToFromTextHelper.bookToYml(path, fileName, bookMetadata);
-            } catch (IOException e) {
+            } catch (IOException exception) {
-                e.printStackTrace();
                 BooksWithoutBorders.sendErrorMessage(player, "Group encrypted failed!");
                 return null;
             }
@@ -312,8 +312,7 @@ public final class EncryptionHelper {
 
         try {
             BookToFromTextHelper.bookToYml(path, fileName, bookMetaData);
-        } catch (IOException e) {
+        } catch (IOException exception) {
-            e.printStackTrace();
             BooksWithoutBorders.sendErrorMessage(player, "Encryption failed!");
             return false;
         }

src/test/java/net/knarcraft/bookswithoutborders/encryption/AESTest.java

@@ -1,9 +1,9 @@
 package net.knarcraft.bookswithoutborders.encryption;
 
-import junit.framework.Assert;
 import org.junit.Test;
 
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotSame;
 
 public class AESTest {
 
@@ -15,7 +15,7 @@ public class AESTest {
         AES aes = new AES(AES.generateIV(), AES.generateIV());
 
         String encrypted = aes.encryptDecryptText(plainText, password, true);
-        Assert.assertNotSame(encrypted, plainText);
+        assertNotSame(encrypted, plainText);
         String decrypted = aes.encryptDecryptText(encrypted, password, false);
         assertEquals(plainText, decrypted);
     }