Package org.refcodes.command

This package provides means to implement your custom commands as of the command pattern: "...

See: Description

Interface Summary

Interface	Description
Command<CTX,RET,E extends Exception>	A Command (Command) represents an (atomic) operation applied to a context returning a result encapsulated in an object (as of object oriented programming).
CommandAccessor<CTX,R,E extends Exception>	Provides an accessor for a command property.
CommandAccessor.CommandBuilder<CTX,R,E extends Exception,B extends CommandAccessor.CommandBuilder<CTX,R,E,B>>	Provides a builder method for a name property returning the builder for applying multiple build operations.
CommandAccessor.CommandMutator<CTX,R,E extends Exception>	Provides a mutator for a command property.
CommandAccessor.CommandProperty<CTX,R,E extends Exception>	Provides a command property.
Undoable<CTX,RET,E extends Exception>	An Undoable is a Command) which also provides means to undo its operation applied before.
UndoableAccessor<CTX,R,E extends Exception>	Provides an accessor for a command property.
UndoableAccessor.UndoableBuilder<CTX,R,E extends Exception,B extends UndoableAccessor.UndoableBuilder<CTX,R,E,B>>	Provides a builder method for a name property returning the builder for applying multiple build operations.
UndoableAccessor.UndoableMutator<CTX,R,E extends Exception>	Provides a mutator for a undoable property.
UndoableAccessor.UndoableProperty<CTX,R,E extends Exception>	Provides a undoable property.
Worker<CTX,E extends Exception>	A Worker represents an (atomic) operation applied to a context and (in contrast to a Command) not returning any result, all of which encapsulated in an object (as of object oriented programming).
WorkerAccessor<CTX,E extends Exception>	Provides an accessor for a command property.
WorkerAccessor.WorkerBuilder<CTX,E extends Exception,B extends WorkerAccessor.WorkerBuilder<CTX,E,B>>	Provides a builder method for a name property returning the builder for applying multiple build operations.
WorkerAccessor.WorkerMutator<CTX,E extends Exception>	Provides a mutator for a worker property.
WorkerAccessor.WorkerProperty<CTX,E extends Exception>	Provides a worker property.

Exception Summary

Exception	Description
CommandRuntimeException
NoExceptionAvailableRuntimeException
NoResultAvailableRuntimeException
NotUndoableRuntimeException
NotYetExecutedRuntimeException

Package org.refcodes.command Description

This package provides means to implement your custom commands as of the command pattern:

"... (in) the command pattern ... an object is used to represent and encapsulate all the information needed to call a method at a later time. This ... includes the ... method parameters ..." [Command pattern, see http://en.wikipedia.org/wiki/Command_pattern (Wikipedia)]

A command can be seen as a method and its context (variables1) all transformed to an object (e.g a method turned inside out).

Given you define a command's interface with an “execute” and an “undo” method and you strictly make use of commands: Then you easily can provide undo functionality by putting your executed commands onto a stack ...

Command:

A Command (respectively an Undoable) represents an (atomic) operation applied to a context encapsulated in an object (as of object oriented programming). Usually a command (Undoable) also provides means to undo its operation applied before. The Command (Undoable) is created by a client (e.g. the business logic) and passed e.g. to a command bus for execution (or executed "manually" at required / desired time).

(a command bus implementation you can find in the "refcodes-jobbus" artifact, see org.refcodes.jobbus.JobBus).

Client:

The client may be the business logic creating a Undoable (job) to be executed.

Context:

The context can be a service, a service-bus (providing a handful of services), a component or a plain POJO (this depends on your requirements and your implementation).