org.refcodes.command

Interface Command<CTX,RET,E extends Exception>

Type Parameters:

CTX - The context type to use, can by any Component, service or POJO.

RET - The return type of the Command's proceedings.

E - The exception type of the Command's erroneous termination.

All Known Subinterfaces:

Undoable<CTX,RET,E>

All Known Implementing Classes:

AbstractCommand, AbstractUndoable

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface 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). An Undoable is a command which provides means to undo its operation applied before. The Command is created by a client (e.g. the business logic) and passed to something like a command-bus or command-processor for execution.

Method Summary

Modifier and Type	Method and Description
RET	execute(CTX aContext) The invoker executes a Command by providing it a context (being a service, a Component or a POJO).

Method Detail

execute

RET execute(CTX aContext)
     throws E extends Exception

The invoker executes a Command by providing it a context (being a service, a Component or a POJO). The method works synchronously and waits (blocks the caller's thread) till a result is available.

Parameters:

aContext - The target object (being a service, a Component or a POJO) which is used by the Command to perform its (atomic) operation.

Returns:

The result of this Command after execution or Void in case this Command does not process a result.

Throws:

E - the e

E extends Exception