com.sk89q.minecraft.util.commands

Class CommandsManager<T>

java.lang.Object

com.sk89q.minecraft.util.commands.CommandsManager<T>

Type Parameters:

T - command sender class

public abstract class CommandsManager<T>
extends Object

Manager for handling commands. This allows you to easily process commands, including nested commands, by correctly annotating methods of a class.

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 execute methods. If something is wrong, such as incorrect usage, insufficient permissions, or a missing command altogether, an exception will be raised for upstream handling.

Methods of a class to be registered can be static, but if an injector is registered with the class, the instances of the command classes will be created automatically and methods will be called non-statically.

To mark a method as a command, use Command. For nested commands, see NestedCommand. To handle permissions, use CommandPermissions.

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

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<Method,Map<String,Method>>	commands Mapping of commands (including aliases) with a description.
protected Map<String,String>	descs Mapping of commands (not including aliases) with a description.
protected Map<String,String>	helpMessages Mapping of commands (not including aliases) with a description.
protected Injector	injector Stores the injector used to getInstance.
protected Map<Method,Object>	instances Used to store the instances associated with a method.
protected static Logger	logger Logger for general errors.

Constructor Summary

Constructors

Constructor and Description
CommandsManager()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	checkPermission(T player, Method method)
void	execute(String[] args, T player, Object... methodArgs) Attempt to execute a command.
void	execute(String cmd, String[] args, T player, Object... methodArgs) Attempt to execute a command.
void	executeMethod(Method parent, String[] args, T player, Object[] methodArgs, int level) Attempt to execute a command.
protected CharSequence	getArguments(Command cmd)
Map<String,String>	getCommands() Get a list of command descriptions.
Map<String,String>	getHelpMessages() Get a map from command name to help message.
Injector	getInjector() Get the injector used to create new instances.
Map<Method,Map<String,Method>>	getMethods()
protected String	getNestedUsage(String[] args, int level, Method method, T player) Get the usage string for a nested command.
protected String	getUsage(String[] args, int level, Command cmd) Get the usage string for a command.
boolean	hasCommand(String command) Checks to see whether there is a command named such at the root level.
protected boolean	hasPermission(Method method, T player) Returns whether a player has access to a command.
abstract boolean	hasPermission(T player, String perm) Returns whether a player permission..
void	invokeMethod(Method parent, String[] args, T player, Method method, Object instance, Object[] methodArgs, int level)
void	register(Class<?> cls) Register an class that contains commands (denoted by Command.
List<Command>	registerAndReturn(Class<?> cls) Register an class that contains commands (denoted by Command.
void	setInjector(Injector injector) Set the injector for creating new instances.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

logger

protected static final Logger logger

Logger for general errors.

commands

protected Map<Method,Map<String,Method>> commands

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 Method. The child map has the key of the command name (one for each alias) with the method.

instances

protected Map<Method,Object> instances

Used to store the instances associated with a method.

descs

protected Map<String,String> descs

Mapping of commands (not including aliases) with a description. This is only for top level commands.

injector

protected Injector injector

Stores the injector used to getInstance.

helpMessages

protected Map<String,String> helpMessages

Mapping of commands (not including aliases) with a description. This is only for top level commands.

Constructor Detail

CommandsManager

public CommandsManager()

Method Detail

register

public void register(Class<?> cls)

Register an class that contains commands (denoted by Command. If no dependency injector is specified, then the methods of the class will be registered to be called statically. Otherwise, new instances will be created of the command classes and methods will not be called statically.

Parameters:

cls -

registerAndReturn

public List<Command> registerAndReturn(Class<?> cls)

Register an class that contains commands (denoted by Command. If no dependency injector is specified, then the methods of the class will be registered to be called statically. Otherwise, new instances will be created of the command classes and methods will not be called statically. A List of Command annotations from registered commands is returned.

Parameters:

cls -

Returns:

A List of Command annotations from registered commands, for use in eg. a dynamic command registration system.

hasCommand

public boolean hasCommand(String command)

Checks to see whether there is a command named such at the root level. This will check aliases as well.

Parameters:

command -

Returns:

getCommands

public Map<String,String> getCommands()

Get a list of command descriptions. This is only for root commands.

Returns:

getMethods

public Map<Method,Map<String,Method>> getMethods()

getHelpMessages

public Map<String,String> getHelpMessages()

Get a map from command name to help message. This is only for root commands.

Returns:

getUsage

protected String getUsage(String[] args,
              int level,
              Command cmd)

Get the usage string for a command.

Parameters:

args -

level -

cmd -

Returns:

getArguments

protected CharSequence getArguments(Command cmd)

getNestedUsage

protected String getNestedUsage(String[] args,
                    int level,
                    Method method,
                    T player)
                         throws CommandException

Get the usage string for a nested command.

Parameters:

args -

level -

method -

player -

Returns:

Throws:

CommandException

execute

public void execute(String cmd,
           String[] args,
           T player,
           Object... methodArgs)
             throws CommandException

Attempt to execute a command. This version takes a separate command name (for the root command) and then a list of following arguments.

Parameters:

cmd - command to run

args - arguments

player - command source

methodArgs - method arguments

Throws:

CommandException

execute

public void execute(String[] args,
           T player,
           Object... methodArgs)
             throws CommandException

Attempt to execute a command.

Parameters:

args -

player -

methodArgs -

Throws:

CommandException

executeMethod

public void executeMethod(Method parent,
                 String[] args,
                 T player,
                 Object[] methodArgs,
                 int level)
                   throws CommandException

Attempt to execute a command.

Parameters:

parent -

args -

player -

methodArgs -

level -

Throws:

CommandException

checkPermission

protected void checkPermission(T player,
                   Method method)
                        throws CommandException

Throws:

CommandException

invokeMethod

public void invokeMethod(Method parent,
                String[] args,
                T player,
                Method method,
                Object instance,
                Object[] methodArgs,
                int level)
                  throws CommandException

Throws:

CommandException

hasPermission

protected boolean hasPermission(Method method,
                    T player)

Returns whether a player has access to a command.

Parameters:

method -

player -

Returns:

hasPermission

public abstract boolean hasPermission(T player,
                    String perm)

Returns whether a player permission..

Parameters:

player -

perm -

Returns:

getInjector

public Injector getInjector()

Get the injector used to create new instances. This can be null, in which case only classes will be registered statically.

setInjector

public void setInjector(Injector injector)

Set the injector for creating new instances.

Parameters:

injector - injector or null