diff --git a/bukkit/pom.xml b/bukkit/pom.xml
index a6a0b17..197c876 100644
--- a/bukkit/pom.xml
+++ b/bukkit/pom.xml
@@ -28,8 +28,8 @@
                     <artifactId>sqlite-jdbc</artifactId>
                 </exclusion>
                 <exclusion>
-                    <groupId>mysql</groupId>
-                    <artifactId>mysql-connector-java</artifactId>
+                    <groupId>com.mysql</groupId>
+                    <artifactId>mysql-connector-j</artifactId>
                 </exclusion>
             </exclusions>
         </dependency>
diff --git a/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/Gui.java b/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/Gui.java
index 7648455..59d87dd 100644
--- a/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/Gui.java
+++ b/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/Gui.java
@@ -2,11 +2,15 @@ package org.zhdev.varioutil.bukkit.gui;
 
 import org.bukkit.Material;
 import org.bukkit.entity.Player;
+import org.bukkit.event.inventory.InventoryCloseEvent;
+import org.bukkit.event.inventory.InventoryOpenEvent;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Objects;
+import java.util.function.Consumer;
 
 public class Gui {
     final GuiHolder holder = new GuiHolder(this);
@@ -16,6 +20,9 @@ public class Gui {
     private String title;
     private GuiType type = GuiType.SIZE_27;
 
+    private Consumer<InventoryOpenEvent> openEvent = inventoryCloseEvent -> {};
+    private Consumer<InventoryCloseEvent> closeEvent = inventoryCloseEvent -> {};
+
     public String getTitle() {
         return title;
     }
@@ -32,6 +39,22 @@ public class Gui {
         this.type = type;
     }
 
+    public Consumer<InventoryOpenEvent> getOpenEvent() {
+        return openEvent;
+    }
+
+    public void setOpenEvent(Consumer<InventoryOpenEvent> openEvent) {
+        this.openEvent = Objects.requireNonNull(openEvent, "openEvent");
+    }
+
+    public Consumer<InventoryCloseEvent> getCloseEvent() {
+        return closeEvent;
+    }
+
+    public void setCloseEvent(Consumer<InventoryCloseEvent> closeEvent) {
+        this.closeEvent = Objects.requireNonNull(closeEvent, "closeEvent");
+    }
+
     public GuiIcon getIcon(int slot) {
         return iconMap.get(slot);
     }
diff --git a/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/GuiIcon.java b/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/GuiIcon.java
index 698d3fe..ca641b7 100644
--- a/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/GuiIcon.java
+++ b/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/GuiIcon.java
@@ -106,7 +106,7 @@ public class GuiIcon {
             if (meta != null) {
                 meta.setDisplayName(displayName);
                 meta.setLore(lore);
-                meta.addItemFlags(flags);
+                if (flags != null) meta.addItemFlags(flags);
                 if (texture != null && meta instanceof SkullMeta) {
                     BukkitUtils.setSkullTexture(((SkullMeta) meta), texture);
                 }
diff --git a/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/GuiListener.java b/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/GuiListener.java
index 72465b4..43fac37 100644
--- a/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/GuiListener.java
+++ b/bukkit/src/main/java/org/zhdev/varioutil/bukkit/gui/GuiListener.java
@@ -5,8 +5,12 @@ import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
 import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.event.inventory.InventoryCloseEvent;
+import org.bukkit.event.inventory.InventoryDragEvent;
+import org.bukkit.event.inventory.InventoryOpenEvent;
 import org.bukkit.event.server.PluginDisableEvent;
 import org.bukkit.inventory.Inventory;
+import org.bukkit.inventory.InventoryHolder;
 import org.bukkit.plugin.Plugin;
 
 public class GuiListener implements Listener {
@@ -17,7 +21,14 @@ public class GuiListener implements Listener {
     }
 
     @EventHandler
-    public void onClick(InventoryClickEvent event) {
+    private void onDrag(InventoryDragEvent event) {
+        if (event.getInventory().getHolder() instanceof GuiHolder) {
+            event.setCancelled(true);
+        }
+    }
+
+    @EventHandler
+    private void onClick(InventoryClickEvent event) {
         if (!(event.getWhoClicked() instanceof Player)) {
             return;
         }
@@ -48,7 +59,23 @@ public class GuiListener implements Listener {
     }
 
     @EventHandler
-    public void onPluginDisable(PluginDisableEvent event) {
+    private void onOpen(InventoryOpenEvent event) {
+        InventoryHolder holder = event.getInventory().getHolder();
+        if (holder instanceof GuiHolder) {
+            ((GuiHolder) holder).gui.getOpenEvent().accept(event);
+        }
+    }
+
+    @EventHandler
+    private void onClose(InventoryCloseEvent event) {
+        InventoryHolder holder = event.getInventory().getHolder();
+        if (holder instanceof GuiHolder) {
+            ((GuiHolder) holder).gui.getCloseEvent().accept(event);
+        }
+    }
+
+    @EventHandler
+    private void onPluginDisable(PluginDisableEvent event) {
         if (event.getPlugin() == plugin) {
             for (Player player : Bukkit.getOnlinePlayers()) {
                 Inventory inventory = player.getOpenInventory().getTopInventory();
diff --git a/bukkit/src/main/java/org/zhdev/varioutil/util/BukkitUtils.java b/bukkit/src/main/java/org/zhdev/varioutil/util/BukkitUtils.java
index ee8a210..cc75588 100644
--- a/bukkit/src/main/java/org/zhdev/varioutil/util/BukkitUtils.java
+++ b/bukkit/src/main/java/org/zhdev/varioutil/util/BukkitUtils.java
@@ -62,7 +62,7 @@ public class BukkitUtils {
         BukkitReflectionUtils.setProfile(meta, profile);
     }
 
-    public static String stacksToString(ItemStack[] contents) {
+    public static String stacksToString(ItemStack... contents) {
         try (ByteArrayOutputStream str = new ByteArrayOutputStream();
              BukkitObjectOutputStream data = new BukkitObjectOutputStream(str)) {
             data.writeInt(contents.length);
diff --git a/db/pom.xml b/db/pom.xml
index 1a0e172..b2ec446 100644
--- a/db/pom.xml
+++ b/db/pom.xml
@@ -29,8 +29,8 @@
             <scope>compile</scope>
         </dependency>
         <dependency>
-            <groupId>mysql</groupId>
-            <artifactId>mysql-connector-java</artifactId>
+            <groupId>com.mysql</groupId>
+            <artifactId>mysql-connector-j</artifactId>
             <version>8.0.33</version>
             <scope>compile</scope>
         </dependency>
diff --git a/db/src/main/java/org/zhdev/varioutil/util/SqlUtils.java b/db/src/main/java/org/zhdev/varioutil/util/SqlUtils.java
index b5392c8..738d7a4 100644
--- a/db/src/main/java/org/zhdev/varioutil/util/SqlUtils.java
+++ b/db/src/main/java/org/zhdev/varioutil/util/SqlUtils.java
@@ -28,7 +28,6 @@ public class SqlUtils {
 
     public static Connection createH2Connection(String path, String username, String password) throws SqlException {
         try {
-            DriverManager.registerDriver(new org.h2.Driver());
             Connection connection;
             if (username != null) {
                 connection = DriverManager.getConnection("jdbc:h2:./" + path + ";mode=MySQL;AUTO_SERVER=TRUE", username, password);
@@ -57,10 +56,7 @@ public class SqlUtils {
             }
         }
         try {
-            Class.forName("org.sqlite.JDBC");
             return DriverManager.getConnection("jdbc:sqlite:" + path);
-        } catch (ClassNotFoundException e) {
-            throw new SqlException("No suitable driver");
         } catch (SQLException e) {
             throw new SqlException(e);
         }
@@ -144,5 +140,6 @@ public class SqlUtils {
     static {
         initializeH2();
         initializeMySql();
+        initializeSqlite();
     }
 }
diff --git a/misc/src/main/java/org/zhdev/varioutil/PreparedPlugin.java b/misc/src/main/java/org/zhdev/varioutil/PreparedPlugin.java
index 5aae0fa..cc50f37 100644
--- a/misc/src/main/java/org/zhdev/varioutil/PreparedPlugin.java
+++ b/misc/src/main/java/org/zhdev/varioutil/PreparedPlugin.java
@@ -10,8 +10,11 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.logging.Logger;
 
 public interface PreparedPlugin {
+    Logger getLogger();
+
     Config getDefaultConfig();
 
     Language getLanguage();
diff --git a/misc/src/main/java/org/zhdev/varioutil/util/ConfigUtils.java b/misc/src/main/java/org/zhdev/varioutil/util/ConfigUtils.java
index c060932..32ecdfb 100644
--- a/misc/src/main/java/org/zhdev/varioutil/util/ConfigUtils.java
+++ b/misc/src/main/java/org/zhdev/varioutil/util/ConfigUtils.java
@@ -7,6 +7,7 @@ import org.zhdev.varioutil.sql.*;
 import java.io.File;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
 import java.util.function.Function;
 
 public class ConfigUtils {
@@ -15,9 +16,12 @@ public class ConfigUtils {
             ConfigSection section = config.getSection(i);
             if (section == null) continue;
             for (String j : section) {
-                String phrase = section.getString(j);
-                if (phrase == null) {
-                    phrase = String.join("\n", CollectionUtils.mapToString(section.getList(j, Collections.emptyList()), ArrayList::new));
+                String phrase;
+                List<?> list = section.getList(j);
+                if (list == null) {
+                    phrase = section.getString(j);
+                } else {
+                    phrase = String.join("\n", CollectionUtils.mapToString(list, ArrayList::new));
                 }
                 language.addPhrase(i, j, function.apply(phrase));
             }
diff --git a/velocity/src/main/java/org/zhdev/varioutil/VelocityPlugin.java b/velocity/src/main/java/org/zhdev/varioutil/VelocityPlugin.java
index 14738c9..b2aa9b6 100644
--- a/velocity/src/main/java/org/zhdev/varioutil/VelocityPlugin.java
+++ b/velocity/src/main/java/org/zhdev/varioutil/VelocityPlugin.java
@@ -24,7 +24,11 @@ public abstract class VelocityPlugin {
         return dataFolder;
     }
 
-    public Logger getLogger() {
+    public java.util.logging.Logger getLogger() {
+        return java.util.logging.Logger.getLogger(logger.getName());
+    }
+
+    public Logger getSLF4JLogger() {
         return logger;
     }
 }
diff --git a/velocity/src/main/java/org/zhdev/varioutil/VelocityPreparedPlugin.java b/velocity/src/main/java/org/zhdev/varioutil/VelocityPreparedPlugin.java
index bdafaf6..bc61bd3 100644
--- a/velocity/src/main/java/org/zhdev/varioutil/VelocityPreparedPlugin.java
+++ b/velocity/src/main/java/org/zhdev/varioutil/VelocityPreparedPlugin.java
@@ -22,9 +22,6 @@ public abstract class VelocityPreparedPlugin extends VelocityPlugin implements P
 
     protected VelocityPreparedPlugin(ProxyServer server, Logger logger, Path dataFolder) {
         super(server, logger, dataFolder);
-        loadConfig(defaultConfig);
-        loadPhrases();
-        establishSqlConnection();
     }
 
     protected SqlAdapter createSqlAdapter() {
@@ -68,6 +65,9 @@ public abstract class VelocityPreparedPlugin extends VelocityPlugin implements P
 
     @Subscribe
     private void onProxyInitialization(ProxyInitializeEvent event) {
+        loadConfig(defaultConfig);
+        loadPhrases();
+        establishSqlConnection();
         onEnabling();
     }