Refactored command handling code to be more reusable.

src/com/sk89q/minecraft/util/commands/Command.java

@@ -21,12 +21,48 @@ package com.sk89q.minecraft.util.commands;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
+/**
+ * This annotation indicates a command. Methods should be marked with this
+ * annotation to tell {@link CommandsManager} that the method is a command.
+ * Note that the method name can actually be anything.
+ *
+ * @author sk89q
+ */
 @Retention(RetentionPolicy.RUNTIME)
 public @interface Command {
+    /**
+     * A list of aliases for the command. The first alias is the most
+     * important -- it is the main name of the command. (The method name
+     * is never used for anything).
+     */
     String[] aliases();
+    
+    /**
+     * Usage instruction. Example text for usage could be
+     * <code>[-h] [name] [message]</code>.
+     */
     String usage() default "";
+    
+    /**
+     * A short description for the command.
+     */
     String desc();
+    
+    /**
+     * The minimum number of arguments. This should be 0 or above.
+     */
     int min() default 0;
+    
+    /**
+     * The maximum number of arguments. Use -1 for an unlimited number
+     * of arguments.
+     */
     int max() default -1;
+    
+    /**
+     * Flags allow special processing for flags such as -h in the command,
+     * allowing users to easily turn on a flag. This is a string with
+     * each character being a flag. Use A-Z and a-z as possible flags.
+     */
     String flags() default "";
 }

src/com/sk89q/minecraft/util/commands/CommandException.java

@@ -0,0 +1,37 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010, 2011 sk89q <http://www.sk89q.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package com.sk89q.minecraft.util.commands;
+
+public class CommandException extends Exception {
+    private static final long serialVersionUID = 870638193072101739L;
+
+    public CommandException() {
+        super();
+    }
+
+    public CommandException(String message) {
+        super(message);
+    }
+
+    public CommandException(Throwable t) {
+        super(t);
+    }
+
+}

src/com/sk89q/minecraft/util/commands/CommandPermissions.java

@@ -22,7 +22,16 @@ package com.sk89q.minecraft.util.commands;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
+/**
+ * Indicates a list of permissions that should be checked.
+ *
+ * @author sk89q
+ */
 @Retention(RetentionPolicy.RUNTIME)
 public @interface CommandPermissions {
+    /**
+     * A list of permissions. Only one permission has to be met
+     * for the command to be permitted.
+     */
     String[] value();
 }

src/com/sk89q/minecraft/util/commands/CommandPermissionsException.java

@@ -0,0 +1,29 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010, 2011 sk89q <http://www.sk89q.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package com.sk89q.minecraft.util.commands;
+
+/**
+ * Thrown when not enough permissions are satisfied.
+ *
+ * @author sk89q
+ */
+public class CommandPermissionsException extends CommandException {
+    private static final long serialVersionUID = -602374621030168291L;
+}

src/com/sk89q/minecraft/util/commands/CommandUsageException.java

@@ -0,0 +1,35 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010, 2011 sk89q <http://www.sk89q.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package com.sk89q.minecraft.util.commands;
+
+public class CommandUsageException extends CommandException {
+    private static final long serialVersionUID = -6761418114414516542L;
+    
+    protected String usage;
+    
+    public CommandUsageException(String message, String usage) {
+        super(message);
+        this.usage = usage;
+    }
+    
+    public String getUsage() {
+        return usage;
+    }
+}

src/com/sk89q/minecraft/util/commands/CommandsManager.java

@@ -28,24 +28,51 @@ import java.util.Set;
 import com.sk89q.util.StringUtil;
 
 /**
- * Manager for handling commands.
+ * Manager for handling commands. This allows you to easily process commands,
+ * including nested commands, by correctly annotating methods of a class.
+ * The commands are thus declaratively defined, and it's easy to spot
+ * how permissions and commands work out, and it decreases the opportunity
+ * for errors because the consistency would cause any odd balls to show. 
+ * The manager also handles some boilerplate code such as number of arguments
+ * checking and printing usage.
+ * 
+ * <p>To use this, it is merely a matter of registering classes containing
+ * the commands (as methods with the proper annotations) with the
+ * manager. When you want to process a command, use one of the
+ * <code>execute</code> methods. If something is wrong, such as incorrect
+ * usage, insufficient permissions, or a missing command altogether, an
+ * exception will be raised for upstream handling.
+ * 
+ * <p>To mark a method as a command, use {@link Command}. For nested commands,
+ * see {@link NestedCommand}. To handle permissions, use
+ * {@link CommandPermissions}.
+ * 
+ * <p>This uses Java reflection extensively, but to reduce the overhead of
+ * reflection, command lookups are completely cached on registration. This
+ * allows for fast command handling. Method invocation still has to be done
+ * with reflection, but this is quite fast in that of itself.
  * 
  * @author sk89q
+ * @param <T> command sender class
  */
-public class CommandsManager {
+public abstract class CommandsManager<T> {
+    
     /**
-     * Mapping of nested commands (including aliases) with a description.
+     * Mapping of commands (including aliases) with a description. Root
+     * commands are stored under a key of null, whereas child commands are
+     * cached under their respective {@link Method}.
      */
-    public Map<Method, Map<String, Method>> commands
+    protected Map<Method, Map<String, Method>> commands
             = new HashMap<Method, Map<String, Method>>();
+    
     /**
      * Mapping of commands (not including aliases) with a description.
      */
-    public Map<String, String> descs = new HashMap<String, String>();
+    protected Map<String, String> descs = new HashMap<String, String>();
     
     /**
-     * Register an object that contains commands (denoted by the
-     * <code>com.sk89q.util.commands.Command</code> annotation. The methods are
+     * Register an object that contains commands (denoted by
+     * {@link Command}. The methods are
      * cached into a map for later usage and it reduces the overhead of
      * reflection (method lookup via reflection is relatively slow).
      * 
@@ -109,7 +136,8 @@ public class CommandsManager {
     }
     
     /**
-     * Checks to see whether there is a command.
+     * Checks to see whether there is a command named such at the root level.
+     * This will check aliases as well.
      * 
      * @param command
      * @return
@@ -119,7 +147,7 @@ public class CommandsManager {
     }
     
     /**
-     * Get a list of command descriptions.
+     * Get a list of command descriptions. This is only for root commands.
      * 
      * @return
      */
@@ -135,7 +163,7 @@ public class CommandsManager {
      * @param cmd
      * @return
      */
-    private String getUsage(String[] args, int level, Command cmd) {
+    protected String getUsage(String[] args, int level, Command cmd) {
         StringBuilder command = new StringBuilder();
         
         command.append("/");
@@ -156,11 +184,13 @@ public class CommandsManager {
      * @param args
      * @param level
      * @param method
-     * @param palyer
+     * @param player
      * @return
+     * @throws CommandException
      */
-    private String getNestedUsage(String[] args, int level, Method method,
-            CommandsPlayer player) {
+    protected String getNestedUsage(String[] args, int level,
+            Method method, T player) throws CommandException {
+        
         StringBuilder command = new StringBuilder();
         
         command.append("/");
@@ -171,6 +201,7 @@ public class CommandsManager {
 
         
         Map<String, Method> map = commands.get(method);
+        boolean found = false;
         
         command.append("<");
         
@@ -178,6 +209,7 @@ public class CommandsManager {
         
         for (Map.Entry<String, Method> entry : map.entrySet()) {
             Method childMethod = entry.getValue();
+            found = true;
             
             if (hasPermission(childMethod, player)) {
                 Command childCmd = childMethod.getAnnotation(Command.class);
@@ -189,7 +221,12 @@ public class CommandsManager {
         if (allowedCommands.size() > 0) {
             command.append(StringUtil.joinString(allowedCommands, "|", 0));
         } else {
-            command.append("action");
+            if (!found) {
+                command.append("?");
+            } else {
+                //command.append("action");
+                throw new CommandPermissionsException();
+            }
         }
         
         command.append(">");
@@ -197,18 +234,42 @@ public class CommandsManager {
         return command.toString();
     }
     
+    /**
+     * Attempt to execute a command. This version takes a separate command
+     * name (for the root command) and then a list of following arguments.
+     * 
+     * @param cmd command to run
+     * @param args arguments
+     * @param player command source
+     * @param methodArgs method arguments
+     * @throws CommandException 
+     */
+    public void execute(String cmd, String[] args, T player,
+            Object ... methodArgs) throws CommandException {
+        
+        String[] newArgs = new String[args.length + 1];
+        System.arraycopy(args, 0, newArgs, 1, args.length);
+        newArgs[0] = cmd;
+        Object[] newMethodArgs = new Object[methodArgs.length + 1];
+        System.arraycopy(methodArgs, 0, newMethodArgs, 1, methodArgs.length);
+        
+        executeMethod(null, newArgs, player, newMethodArgs, 0);
+    }
+    
     /**
      * Attempt to execute a command.
      * 
      * @param args
      * @param player
      * @param methodArgs
-     * @return
-     * @throws Throwable 
+     * @throws CommandException 
      */
-    public boolean execute(String[] args, CommandsPlayer player,
-            Object[] methodArgs) throws Throwable {
-        return executeMethod(null, args, player, methodArgs, 0);
+    public void execute(String[] args, T player,
+            Object ... methodArgs) throws CommandException {
+        
+        Object[] newMethodArgs = new Object[methodArgs.length + 1];
+        System.arraycopy(methodArgs, 0, newMethodArgs, 1, methodArgs.length);
+        executeMethod(null, args, player, newMethodArgs, 0);
     }
     
     /**
@@ -219,12 +280,11 @@ public class CommandsManager {
      * @param player
      * @param methodArgs
      * @param level
-     * @return
-     * @throws Throwable 
+     * @throws CommandException 
      */
-    public boolean executeMethod(Method parent, String[] args,
-            CommandsPlayer player, Object[] methodArgs, int level)
-            throws Throwable {
+    public void executeMethod(Method parent, String[] args,
+            T player, Object[] methodArgs, int level) throws CommandException {
+        
         String cmdName = args[level];
         
         Map<String, Method> map = commands.get(parent);
@@ -232,25 +292,25 @@ public class CommandsManager {
         
         if (method == null) {
             if (parent == null) { // Root
-                return false;
+                throw new UnhandledCommandException();
             } else {
-                player.printError(getNestedUsage(args, level - 1, parent, player));
-                return true;
+                throw new MissingNestedCommandException("Unknown command: " + cmdName,
+                        getNestedUsage(args, level - 1, parent, player));
             }
         }
         
-        if (!checkPermissions(method, player)) {
-            return true;
+        if (!hasPermission(method, player)) {
+            throw new CommandPermissionsException();
         }
         
         int argsCount = args.length - 1 - level;
 
         if (method.isAnnotationPresent(NestedCommand.class)) {
             if (argsCount == 0) {
-                player.printError(getNestedUsage(args, level, method, player));
-                return true;
+                throw new MissingNestedCommandException("Sub-command required.", 
+                        getNestedUsage(args, level, method, player));
             } else {
-                return executeMethod(method, args, player, methodArgs, level + 1);
+                executeMethod(method, args, player, methodArgs, level + 1);
             }
         } else {
             Command cmd = method.getAnnotation(Command.class);
@@ -261,22 +321,19 @@ public class CommandsManager {
             CommandContext context = new CommandContext(newArgs);
             
             if (context.argsLength() < cmd.min()) {
-                player.printError("Too few arguments.");
-                player.printError(getUsage(args, level, cmd));
-                return true;
+                throw new CommandUsageException("Too few arguments.",
+                        getUsage(args, level, cmd));
             }
             
             if (cmd.max() != -1 && context.argsLength() > cmd.max()) {
-                player.printError("Too many arguments.");
-                player.printError(getUsage(args, level, cmd));
-                return true;
+                throw new CommandUsageException("Too many arguments.",
+                        getUsage(args, level, cmd));
             }
             
             for (char flag : context.getFlags()) {
                 if (cmd.flags().indexOf(String.valueOf(flag)) == -1) {
-                    player.printError("Unknown flag: " + flag);
-                    player.printError(getUsage(args, level, cmd));
-                    return true;
+                    throw new CommandUsageException("Unknown flag: " + flag,
+                            getUsage(args, level, cmd));
                 }
             }
             
@@ -289,35 +346,9 @@ public class CommandsManager {
             } catch (IllegalAccessException e) {
                 e.printStackTrace();
             } catch (InvocationTargetException e) {
-                throw e.getCause();
+                throw new WrappedCommandException(e.getCause());
             }
         }
-        
-        return true;
-    }
-    
-    /**
-     * Checks permissions, prints an error if needed.
-     * 
-     * @param method
-     * @param player
-     * @return
-     */
-    private boolean checkPermissions(Method method, CommandsPlayer player) {
-        if (!method.isAnnotationPresent(CommandPermissions.class)) {
-            return true;
-        }
-
-        CommandPermissions perms = method.getAnnotation(CommandPermissions.class);
-        
-        for (String perm : perms.value()) {
-            if (player.hasPermission(perm)) {
-                return true;
-            }
-        }
-        
-        player.printError("You don't have permission for this command.");
-        return false;
     }
     
     /**
@@ -327,18 +358,27 @@ public class CommandsManager {
      * @param player
      * @return
      */
-    private boolean hasPermission(Method method, CommandsPlayer player) {
+    protected boolean hasPermission(Method method, T player) {
         CommandPermissions perms = method.getAnnotation(CommandPermissions.class);
         if (perms == null) {
             return true;
         }
         
         for (String perm : perms.value()) {
-            if (player.hasPermission(perm)) {
+            if (hasPermission(player, perm)) {
                 return true;
             }
         }
         
         return false;
     }
+    
+    /**
+     * Returns whether a player permission..
+     * 
+     * @param player
+     * @param perm
+     * @return
+     */
+    public abstract boolean hasPermission(T player, String perm);
 }

src/com/sk89q/minecraft/util/commands/MissingNestedCommandException.java

@@ -0,0 +1,29 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010, 2011 sk89q <http://www.sk89q.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package com.sk89q.minecraft.util.commands;
+
+public class MissingNestedCommandException extends CommandUsageException {
+    private static final long serialVersionUID = -4382896182979285355L;
+
+    public MissingNestedCommandException(String message, String usage) {
+        super(message, usage);
+    }
+
+}

src/com/sk89q/minecraft/util/commands/NestedCommand.java

@@ -22,7 +22,20 @@ package com.sk89q.minecraft.util.commands;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
+/**
+ * Indicates a nested command. Mark methods with this annotation to tell
+ * {@link CommandsManager} that a method is merely a shell for child
+ * commands. Note that the body of a method marked with this annotation
+ * will never called. Additionally, not all fields of {@link Command} apply
+ * when it is used in conjunction with this annotation, although both
+ * are still required.
+ *
+ * @author sk89q
+ */
 @Retention(RetentionPolicy.RUNTIME)
 public @interface NestedCommand {
+    /**
+     * A list of classes with the child commands.
+     */
     Class<?>[] value();
 }

src/com/sk89q/minecraft/util/commands/UnhandledCommandException.java

@@ -19,7 +19,7 @@
 
 package com.sk89q.minecraft.util.commands;
 
-public interface CommandsPlayer {
-    public void printError(String msg);
-    public boolean hasPermission(String perm);
+public class UnhandledCommandException extends CommandException {
+    private static final long serialVersionUID = 3370887306593968091L;
+
 }

src/com/sk89q/minecraft/util/commands/WrappedCommandException.java

@@ -0,0 +1,28 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010, 2011 sk89q <http://www.sk89q.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package com.sk89q.minecraft.util.commands;
+
+public class WrappedCommandException extends CommandException {
+    private static final long serialVersionUID = -4075721444847778918L;
+    
+    public WrappedCommandException(Throwable t) {
+        super(t);
+    }
+}

src/com/sk89q/worldedit/LocalPlayer.java

@@ -20,7 +20,6 @@
 package com.sk89q.worldedit;
 
 import java.io.File;
-import com.sk89q.minecraft.util.commands.CommandsPlayer;
 import com.sk89q.worldedit.bags.BlockBag;
 import com.sk89q.worldedit.blocks.BlockType;
 import com.sk89q.worldedit.util.TargetBlock;
@@ -29,7 +28,7 @@ import com.sk89q.worldedit.util.TargetBlock;
  *
  * @author sk89q
  */
-public abstract class LocalPlayer implements CommandsPlayer {    
+public abstract class LocalPlayer {    
     /**
      * Server.
      */

src/com/sk89q/worldedit/WorldEdit.java

@@ -23,7 +23,12 @@ import java.util.*;
 import java.util.logging.Logger;
 import java.io.*;
 import javax.script.ScriptException;
+import com.sk89q.minecraft.util.commands.CommandPermissionsException;
+import com.sk89q.minecraft.util.commands.CommandUsageException;
 import com.sk89q.minecraft.util.commands.CommandsManager;
+import com.sk89q.minecraft.util.commands.MissingNestedCommandException;
+import com.sk89q.minecraft.util.commands.UnhandledCommandException;
+import com.sk89q.minecraft.util.commands.WrappedCommandException;
 import com.sk89q.util.StringUtil;
 import com.sk89q.worldedit.LocalSession.CompassMode;
 import com.sk89q.worldedit.bags.BlockBag;
@@ -67,7 +72,7 @@ public class WorldEdit {
     /**
      * List of commands.
      */
-    private CommandsManager commands;
+    private CommandsManager<LocalPlayer> commands;
     
     /**
      * Stores a list of WorldEdit sessions, keyed by players' names. Sessions
@@ -96,7 +101,12 @@ public class WorldEdit {
         this.server = server;
         this.config = config;
         
-        commands = new CommandsManager();
+        commands = new CommandsManager<LocalPlayer>() {
+            @Override
+            public boolean hasPermission(LocalPlayer player, String perm) {
+                return player.hasPermission(perm);
+            }
+        };
 
         commands.register(ChunkCommands.class);
         commands.register(ClipboardCommands.class);
@@ -887,11 +897,18 @@ public class WorldEdit {
                             + StringUtil.joinString(split, " "));
                 }
 
-                Object[] methodArgs = new Object[] {
-                        null, this, session, player, editSession
-                        };
-
-                return commands.execute(split, player, methodArgs);
+                commands.execute(split, player, this, session, player, editSession);
+            } catch (CommandPermissionsException e) {
+                player.printError("You don't have permission to do this.");
+            } catch (MissingNestedCommandException e) {
+                player.printError(e.getUsage());
+            } catch (CommandUsageException e) {
+                player.printError(e.getMessage());
+                player.printError(e.getUsage());
+            } catch (WrappedCommandException e) {
+                throw e.getCause();
+            } catch (UnhandledCommandException e) {
+                return false;
             } finally {
                 session.remember(editSession);
                 editSession.flushQueue();