review concerns

Essentials/src/main/java/com/earth2me/essentials/Essentials.java

@@ -432,6 +432,9 @@ public class Essentials extends JavaPlugin implements net.ess3.api.IEssentials {
                             ((Cancellable) event).setCancelled(true);
                         }
                     });
+                    if (getSettings().isDebug()) {
+                        LOGGER.log(Level.INFO, "Registered Paper Recipe Book Event Listener");
+                    }
                 } catch (final ClassNotFoundException ignored) {
                 }
             }
@@ -439,7 +442,7 @@ public class Essentials extends JavaPlugin implements net.ess3.api.IEssentials {
             execTimer.mark("Init(Providers)");
             reload();
 
-            // The item spawn blacklist is loaded with all other settings, before the item\
+            // The item spawn blacklist is loaded with all other settings, before the item
             // DB, but it depends on the item DB, so we need to reload it again here:
             ((Settings) settings)._lateLoadItemSpawnBlacklist();
             backup = new Backup(this);
@@ -667,12 +670,10 @@ public class Essentials extends JavaPlugin implements net.ess3.api.IEssentials {
 
             // Check for disabled commands
             if (getSettings().isCommandDisabled(commandLabel)) {
-                if (provider(KnownCommandsProvider.class).getKnownCommands().containsKey(commandLabel)) {
                 final Command newCmd = provider(KnownCommandsProvider.class).getKnownCommands().get(commandLabel);
-                    if (!(newCmd instanceof PluginIdentifiableCommand) || ((PluginIdentifiableCommand) newCmd).getPlugin() != this) {
+                if (newCmd != null && (!(newCmd instanceof PluginIdentifiableCommand) || ((PluginIdentifiableCommand) newCmd).getPlugin() != this)) {
                     return newCmd.tabComplete(cSender, commandLabel, args);
                 }
-                }
                 return Collections.emptyList();
             }
 
@@ -778,12 +779,10 @@ public class Essentials extends JavaPlugin implements net.ess3.api.IEssentials {
 
             // Check for disabled commands
             if (getSettings().isCommandDisabled(commandLabel)) {
-                if (provider(KnownCommandsProvider.class).getKnownCommands().containsKey(commandLabel)) {
                 final Command newCmd = provider(KnownCommandsProvider.class).getKnownCommands().get(commandLabel);
-                    if (!(newCmd instanceof PluginIdentifiableCommand) || !isEssentialsPlugin(((PluginIdentifiableCommand) newCmd).getPlugin())) {
+                if (newCmd != null && (!(newCmd instanceof PluginIdentifiableCommand) || !isEssentialsPlugin(((PluginIdentifiableCommand) newCmd).getPlugin()))) {
                     return newCmd.execute(cSender, commandLabel, args);
                 }
-                }
                 sender.sendTl("commandDisabled", commandLabel);
                 return true;
             }

Essentials/src/main/java/com/earth2me/essentials/ProviderFactory.java

@@ -2,6 +2,7 @@ package com.earth2me.essentials;
 
 import io.papermc.lib.PaperLib;
 import net.ess3.provider.Provider;
+import net.essentialsx.providers.NullableProvider;
 import net.essentialsx.providers.ProviderData;
 import net.essentialsx.providers.ProviderTest;
 import org.bukkit.plugin.Plugin;
@@ -55,6 +56,7 @@ public class ProviderFactory {
     public void finalizeRegistration() {
         for (final Map.Entry<Class<? extends Provider>, List<Class<? extends Provider>>> entry : registeredProviders.entrySet()) {
             final Class<? extends Provider> providerClass = entry.getKey();
+            final boolean nullable = providerClass.isAnnotationPresent(NullableProvider.class);
             Class<? extends Provider> highestProvider = null;
             ProviderData highestProviderData = null;
             int highestWeight = -1;
@@ -70,12 +72,13 @@ public class ProviderFactory {
                     essentials.getLogger().log(Level.SEVERE, "Failed to initialize provider " + provider.getName(), e);
                 }
             }
-            if (highestProvider == null) {
-                throw new IllegalStateException("No provider found for " + providerClass.getName());
-            }
 
+            if (highestProvider != null) {
                 essentials.getLogger().info("Selected " + highestProviderData.description() + " as the provider for " + providerClass.getSimpleName());
                 providers.put(providerClass, getProviderInstance(highestProvider));
+            } else if (!nullable) {
+                throw new IllegalStateException("No provider found for " + providerClass.getName());
+            }
         }
         registeredProviders.clear();
     }

Essentials/src/main/java/com/earth2me/essentials/RandomTeleport.java

@@ -35,7 +35,7 @@ public class RandomTeleport implements IConf {
     public RandomTeleport(final IEssentials essentials) {
         this.ess = essentials;
         config = new EssentialsConfiguration(new File(essentials.getDataFolder(), "tpr.yml"), "/tpr.yml",
-                "Configuration for the random teleport command.\nSome settings may be defaulted, and can be changed via the /settpr command in-game.");
+                "Configuration for the random teleport command.\nUse the /settpr command in-game to set random teleport locations.");
     }
 
     public EssentialsConfiguration getConfig() {

providers/BaseProviders/src/main/java/net/ess3/provider/BiomeKeyProvider.java

@@ -1,8 +1,10 @@
 package net.ess3.provider;
 
+import net.essentialsx.providers.NullableProvider;
 import org.bukkit.NamespacedKey;
 import org.bukkit.block.Block;
 
+@NullableProvider
 public interface BiomeKeyProvider extends Provider {
     NamespacedKey getBiomeKey(Block block);
 }

providers/BaseProviders/src/main/java/net/ess3/provider/ContainerProvider.java

@@ -1,8 +1,10 @@
 package net.ess3.provider;
 
+import net.essentialsx.providers.NullableProvider;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.InventoryView;
 
+@NullableProvider
 public interface ContainerProvider extends Provider {
 
     InventoryView openAnvil(Player player);

providers/BaseProviders/src/main/java/net/ess3/provider/SerializationProvider.java

@@ -1,7 +1,9 @@
 package net.ess3.provider;
 
+import net.essentialsx.providers.NullableProvider;
 import org.bukkit.inventory.ItemStack;
 
+@NullableProvider
 public interface SerializationProvider extends Provider {
     byte[] serializeItem(ItemStack stack);
 

providers/BaseProviders/src/main/java/net/ess3/provider/SignDataProvider.java

@@ -1,7 +1,9 @@
 package net.ess3.provider;
 
+import net.essentialsx.providers.NullableProvider;
 import org.bukkit.block.Sign;
 
+@NullableProvider
 public interface SignDataProvider extends Provider {
     void setSignData(Sign sign, String key, String value);
 

providers/BaseProviders/src/main/java/net/essentialsx/providers/NullableProvider.java

@@ -0,0 +1,14 @@
+package net.essentialsx.providers;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marks a provider as nullable, meaning that an error will not be thrown if no provider is found for the given type.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface NullableProvider {
+}