fixes issue with bbox reload command

https://github.com/BentoBoxWorld/BentoBox/issues/731

Issue was that classes were not being fully removed from class loaders
and commands needed to be unregistered from Bukkit. For the latter,
reflection was required to obtain the knownCommand map and change it
because there is no Bukkit API to unregister commands.

src/main/java/world/bentobox/bentobox/api/addons/AddonClassLoader.java

@@ -21,6 +21,7 @@ import java.net.URLClassLoader;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * Loads addons and sets up permissions
@@ -155,4 +156,11 @@ public class AddonClassLoader extends URLClassLoader {
         return addon;
     }
 
+    /**
+     * @return class list
+     */
+    public Set<String> getClasses() {
+        return classes.keySet();
+    }
+
 }

src/main/java/world/bentobox/bentobox/commands/BentoBoxReloadCommand.java

@@ -1,15 +1,13 @@
 package world.bentobox.bentobox.commands;
 
-import world.bentobox.bentobox.api.addons.Addon;
-import world.bentobox.bentobox.api.commands.CompositeCommand;
-import world.bentobox.bentobox.api.commands.ConfirmableCommand;
-import world.bentobox.bentobox.api.localization.TextVariables;
-import world.bentobox.bentobox.api.user.User;
-
 import java.util.List;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
+import world.bentobox.bentobox.api.commands.CompositeCommand;
+import world.bentobox.bentobox.api.commands.ConfirmableCommand;
+import world.bentobox.bentobox.api.user.User;
+
 /**
  * Reloads settings, addons and localization.
  *
@@ -36,7 +34,7 @@ public class BentoBoxReloadCommand extends ConfirmableCommand {
     @Override
     public boolean execute(User user, String label, List<String> args) {
         if (args.isEmpty()) {
-            this.askConfirmation(user, () -> {
+            this.askConfirmation(user, user.getTranslation("commands.bentobox.reload.warning"), () -> {
                 // Reload settings
                 getPlugin().loadSettings();
                 user.sendMessage("commands.bentobox.reload.settings-reloaded");
@@ -49,18 +47,6 @@ public class BentoBoxReloadCommand extends ConfirmableCommand {
                 getPlugin().getLocalesManager().reloadLanguages();
                 user.sendMessage("commands.bentobox.reload.locales-reloaded");
             });
-        } else if (args.size() == 1) {
-            Optional<Addon> addon = getPlugin().getAddonsManager().getAddonByName(args.get(0));
-            if (!addon.isPresent()) {
-                user.sendMessage("commands.bentobox.reload.unknown-addon");
-                return false;
-            }
-
-            this.askConfirmation(user, () -> {
-                user.sendMessage("commands.bentobox.reload.addon", TextVariables.NAME, addon.get().getDescription().getName());
-                addon.ifPresent(getPlugin().getAddonsManager()::reloadAddon);
-                user.sendMessage("commands.bentobox.reload.addon-reloaded", TextVariables.NAME, addon.get().getDescription().getName());
-            });
         } else {
             showHelp(this, user);
         }

src/main/java/world/bentobox/bentobox/managers/AddonsManager.java

@@ -1,27 +1,9 @@
 package world.bentobox.bentobox.managers;
 
-import org.bukkit.Bukkit;
-import org.bukkit.configuration.InvalidConfigurationException;
-import org.bukkit.configuration.file.YamlConfiguration;
-import org.bukkit.event.HandlerList;
-import org.bukkit.event.Listener;
-import org.bukkit.generator.ChunkGenerator;
-import org.eclipse.jdt.annotation.NonNull;
-import org.eclipse.jdt.annotation.Nullable;
-import world.bentobox.bentobox.BentoBox;
-import world.bentobox.bentobox.api.addons.Addon;
-import world.bentobox.bentobox.api.addons.AddonClassLoader;
-import world.bentobox.bentobox.api.addons.GameModeAddon;
-import world.bentobox.bentobox.api.addons.exceptions.InvalidAddonFormatException;
-import world.bentobox.bentobox.api.configuration.ConfigObject;
-import world.bentobox.bentobox.api.events.addon.AddonEvent;
-import world.bentobox.bentobox.database.objects.DataObject;
-
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStreamReader;
-import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -35,6 +17,26 @@ import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.stream.Collectors;
 
+import org.bukkit.Bukkit;
+import org.bukkit.configuration.InvalidConfigurationException;
+import org.bukkit.configuration.file.YamlConfiguration;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.Listener;
+import org.bukkit.generator.ChunkGenerator;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
+
+import world.bentobox.bentobox.BentoBox;
+import world.bentobox.bentobox.api.addons.Addon;
+import world.bentobox.bentobox.api.addons.Addon.State;
+import world.bentobox.bentobox.api.addons.AddonClassLoader;
+import world.bentobox.bentobox.api.addons.GameModeAddon;
+import world.bentobox.bentobox.api.addons.exceptions.InvalidAddonFormatException;
+import world.bentobox.bentobox.api.configuration.ConfigObject;
+import world.bentobox.bentobox.api.events.addon.AddonEvent;
+import world.bentobox.bentobox.commands.BentoBoxCommand;
+import world.bentobox.bentobox.database.objects.DataObject;
+
 /**
  * @author tastybento, ComminQ
  */
@@ -213,19 +215,29 @@ public class AddonsManager {
      */
     public void reloadAddons() {
         disableAddons();
+        // Reload BentoBox commands
+        new BentoBoxCommand();
         loadAddons();
         enableAddons();
     }
 
     /**
-     * Reloads one addon
+     * Disable all the enabled addons
-     * @param addon - addon
      */
-    public void reloadAddon(Addon addon) {
+    public void disableAddons() {
-        Path p = addon.getFile().toPath();
+        if (!getEnabledAddons().isEmpty()) {
-        disable(addon);
+            plugin.log("Disabling addons...");
-        loadAddon(p.toFile());
+            // Disable addons
-        enableAddon(addon);
+            getEnabledAddons().forEach(this::disable);
+            plugin.log("Addons successfully disabled.");
+        }
+        // Unregister all commands
+        plugin.getCommandsManager().unregisterCommands();
+        // Clear all maps
+        listeners.clear();
+        addons.clear();
+        loaders.clear();
+        classes.clear();
     }
 
     /**
@@ -253,23 +265,6 @@ public class AddonsManager {
         return data;
     }
 
-    /**
-     * Disable all the enabled addons
-     */
-    public void disableAddons() {
-        if (!getEnabledAddons().isEmpty()) {
-            plugin.log("Disabling addons...");
-            // Disable addons
-            getEnabledAddons().forEach(this::disable);
-            plugin.log("Addons successfully disabled.");
-        }
-        // Clear all maps
-        listeners.clear();
-        addons.clear();
-        loaders.clear();
-        classes.clear();
-    }
-
     @NonNull
     public List<Addon> getAddons() {
         return addons;
@@ -422,11 +417,9 @@ public class AddonsManager {
         }
         // Clear loaders
         if (loaders.containsKey(addon)) {
-            try {
+            loaders.get(addon).getClasses().forEach(classes::remove);
-                loaders.get(addon).close();
+            addon.setState(State.DISABLED);
-            } catch (IOException ignore) {
+            loaders.remove(addon);
-                // Nothing
-            }
         }
 
         // Remove it from the addons list

src/main/java/world/bentobox/bentobox/managers/CommandsManager.java

@@ -7,16 +7,19 @@ import java.util.Map;
 import java.util.Set;
 
 import org.bukkit.Bukkit;
-import org.bukkit.command.CommandMap;
+import org.bukkit.command.Command;
+import org.bukkit.command.SimpleCommandMap;
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
 
+import world.bentobox.bentobox.BentoBox;
 import world.bentobox.bentobox.api.commands.CompositeCommand;
 
 public class CommandsManager {
 
     @NonNull
     private Map<@NonNull String, @NonNull CompositeCommand> commands = new HashMap<>();
+    private SimpleCommandMap commandMap;
 
     public void registerCommand(@NonNull CompositeCommand command) {
         commands.put(command.getLabel(), command);
@@ -24,20 +27,39 @@ public class CommandsManager {
         try{
             Field commandMapField = Bukkit.getServer().getClass().getDeclaredField("commandMap");
             commandMapField.setAccessible(true);
-            CommandMap commandMap = (CommandMap) commandMapField.get(Bukkit.getServer());
+            commandMap = (SimpleCommandMap) commandMapField.get(Bukkit.getServer());
 
             String commandPrefix = "bentobox";
             if (command.getAddon() != null) {
                 commandPrefix = command.getAddon().getDescription().getName().toLowerCase(Locale.ENGLISH);
             }
-
+            if (!commandMap.register(commandPrefix, command)) {
-            commandMap.register(commandPrefix, command);
+                BentoBox.getInstance().logError("Failed to register command " + commandPrefix + " " + command.getLabel());
+            }
         }
         catch(Exception exception){
             Bukkit.getLogger().severe("Bukkit server commandMap method is not there! This means no commands can be registered!");
         }
     }
 
+    /**
+     * Unregisters all BentoBox registered commands with Bukkit
+     */
+    public void unregisterCommands() {
+        // Use reflection to obtain the knownCommands in the commandMap
+        try {
+            @SuppressWarnings("unchecked")
+            Map<String, Command> knownCommands = (Map<String, Command>) commandMap.getClass().getMethod("getKnownCommands").invoke(commandMap);
+            knownCommands.values().removeIf(commands.values()::contains);
+            // Not sure if this is needed, but it clears out all references
+            commands.values().forEach(c -> c.unregister(commandMap));
+            // Zap everything
+            commands.clear();
+        } catch(Exception e){
+            Bukkit.getLogger().severe("Known commands reflection was not possible, BentoBox is now unstable, so restart server!");
+        }
+    }
+
     /**
      * Try to get a registered command.
      * @param command - command string

src/main/resources/locales/en-US.yml

@@ -305,13 +305,13 @@ commands:
     about:
       description: "display copyright and license info"
     reload:
-      parameters: "[addon]"
+      description: "reloads BentoBox and all addons, settings and locales"
-      description: "reloads all addons, settings and locales or reloads an individual addon"
       locales-reloaded: "&2Languages reloaded."
       addons-reloaded: "&2Addons reloaded."
       settings-reloaded: "&2Settings reloaded."
       addon: "&6Reloading &b[name]&2."
       addon-reloaded: "&b[name] &2reloaded."
+      warning: "&cWarning: Reloading may cause instability, so if you see errors afterwards, restart the server"
       unknown-addon: "&2Unknown addon!"
     version:
       plugin-version: "&2BentoBox version: &3[version]"

src/main/resources/locales/it-IT.yml

@@ -300,8 +300,7 @@ commands:
     about:
       description: "mostra le info riguardo copyright e licenza"
     reload:
-      parameters: "[addon]"
+      description: "ricarica gli addons, le impostazioni, i locali"
-      description: "ricarica gli addons, le impostazioni, i locali o ricarica un singolo addon"
       locales-reloaded: "&2Linguaggi ricaricati."
       addons-reloaded: "&2Addons ricaricati."
       settings-reloaded: "&2Impostazioni ricaricate."

src/main/resources/locales/lv-LV.yml

@@ -313,7 +313,6 @@ commands:
       locales-reloaded: "&2Valodas faili pārlādēti."
       addons-reloaded: "&2Papildinājumu pārlādēti."
       settings-reloaded: "&2Iestatījumi pārlādēti."
-      parameters: '[addon]'
       addon: '&6Pārlādē &b[name]&2.'
       addon-reloaded: '&b[name] &2pārlādēts.'
       unknown-addon: '&2Nezināms papildinājums!'

src/test/java/world/bentobox/bentobox/managers/AddonsManagerTest.java

@@ -29,7 +29,6 @@ import org.powermock.reflect.Whitebox;
 
 import world.bentobox.bentobox.BentoBox;
 import world.bentobox.bentobox.api.addons.Addon;
-import world.bentobox.bentobox.api.addons.AddonDescription;
 import world.bentobox.bentobox.database.objects.DataObject;
 
 @RunWith(PowerMockRunner.class)
@@ -105,23 +104,6 @@ public class AddonsManagerTest {
         verify(plugin, never()).log("Disabling addons...");
     }
 
-    /**
-     * Test method for {@link world.bentobox.bentobox.managers.AddonsManager#reloadAddon(world.bentobox.bentobox.api.addons.Addon)}.
-     */
-    @Test
-    public void testReloadAddon() {
-        Addon addon = mock(Addon.class);
-        when(addon.isEnabled()).thenReturn(true);
-        File f = new File(plugin.getDataFolder(), "addons");
-        File file = new File(f, "addon.jar");
-        when(addon.getFile()).thenReturn(file);
-        AddonDescription desc = new AddonDescription.Builder("main", "addon-name", "1.0").build();
-        when(addon.getDescription()).thenReturn(desc);
-        am.reloadAddon(addon);
-        verify(plugin).log("Disabling addon-name...");
-        verify(addon).onDisable();
-    }
-
     /**
      * Test method for {@link world.bentobox.bentobox.managers.AddonsManager#getAddonByName(java.lang.String)}.
      */