com.wandrell.pattern.command.package-info Maven / Gradle / Ivy
/**
* The MIT License (MIT)
*
* Copyright (c) 2014 the original author or authors.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/**
* Provides interfaces and basic implementations for the command and command
* executor patterns.
*
* The command is a behavioral pattern which encapsulates a series of
* instructions inside an object, so they can be executed when required, not
* needing to know the actual code being run.
*
* In practice, this is like a macro which can be sent through a network, stored
* or chained to other commands to be executed in order, or even backwards to
* undo them.
*
* They may be executed manually, but to increase decoupling a command executor
* can be used. It additionally can handle any other required operation, such as
* setting up the environment or catching exceptions.
*
Command
*
* The basic command takes the shape of the
* {@link com.wandrell.pattern.command.Command Command}. This does nothing
* expect being executed.
*
* The {@link com.wandrell.pattern.command.ResultCommand ResultCommand} creates
* an object during it's execution, which may be acquired through the
* {@link com.wandrell.pattern.command.ResultCommand#getResult() getResult}
* method.
*
* When it is needed to undo the command
* {@link com.wandrell.pattern.command.UndoableCommand UndoableCommand} should
* be used, and the {@link com.wandrell.pattern.command.UndoableCommand#undo()
* undo} method implemented.
*
Command Executor
*
* Command executors are implemented from the
* {@link com.wandrell.pattern.command.CommandExecutor CommandExecutor}
* interface.
*
* This offers methods for executing and undoing commands, and in the case a
* {@code ResultCommand} is executed this will return the value generated from
* said command.
*
Implementations
*
* Only the {@code CommandExecutor} has a basic implementation, the
* {@link com.wandrell.pattern.command.DefaultCommandExecutor
* DefaultCommandExecutor}, which does little more than receiving a
* {@code Command} and calling its methods.
*
* Commands are meant to be created on a case-by-case basis, to fit concrete
* needs, so no default implementation is offered for them.
*/
package com.wandrell.pattern.command;