Package org.openmuc.jeebus.ship.state.machine

Interface StateHandler

All Known Implementing Classes:

ClientEvaluate, ClientInit, ClientListenChoice, ClientSend, ClientServerWait, CloseDevA, CloseDevB, CmiInitStart, ConnectionDataExchange, ConnectionDataPreparation, HelloOk, InitListen, PendingInit, PendingListen, PendingTimeout, PinOk, ProtHOk, ReadyInit, ReadyListen, ReadyTimeout, ServerEvaluate, ServerInit, ServerListenConfirm, ServerListenProposal, Timeout

public interface StateHandler

A StateHandler is a collection of event handlers associated with a given SHIP connection state. Its methods will be called by the state machine if it is in the appropriate state and the corresponding event occurs.

Any class that implements this interface should be totally stateless, i.e. should have no non-final fields and no fields that contain mutable objects. Instances also should not directly start timers, communicate over the network, etc. Instead, these should be done via the StateHandlerContext passed to each method.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	StateHandler.Handles	Indicates which state(s) this handler takes care of.
static interface	StateHandler.UsesExtraData	Indicates that this state needs some extra data of the specified type.

Field Summary

Fields

Modifier and Type	Field	Description
static org.slf4j.Logger	LOGGER
static StateHandler	UNIMPLEMENTED	Placeholder value.

Method Summary

Modifier and Type	Method	Description
default java.lang.Class<?>	getExtraDataType()
default void	onBeforeExit(State pendingNext, StateHandlerContext context)	Called just before the state machine transitions to a next state.
default void	onEntered(State previous, StateHandlerContext context)	Called when the state machine enters this state.
default void	onMessageReceived(StateHandlerContext context)	Called when a message was received from the communication partner.
default void	onTimeoutExpired(SpecifiedTimeout kind, StateHandlerContext context)	Called when a previously started timeout expires.
default void	processMessage(byte[] msg, StateHandlerContext context)	Called after StateHandlerContext.processMessage().

Field Detail

LOGGER

static final org.slf4j.Logger LOGGER

UNIMPLEMENTED

static final StateHandler UNIMPLEMENTED

Placeholder value.

Method Detail

onEntered

default void onEntered(State previous,
                       StateHandlerContext context)

Called when the state machine enters this state.

Invoking StateHandlerContext.transitionTo(State) inside this method will defer the transition until onEntered finishes.

Parameters:

previous - the previous state

context - the execution context

onBeforeExit

default void onBeforeExit(State pendingNext,
                          StateHandlerContext context)

Called just before the state machine transitions to a next state.

Invoking StateHandlerContext.transitionTo(State) inside this method is an error.

Parameters:

pendingNext - the state that will be entered

context - the execution context

onMessageReceived

default void onMessageReceived(StateHandlerContext context)

Called when a message was received from the communication partner.

If you wish to evaluate the message, the returned command should contain StateHandlerContext.processMessage(), which will cause processMessage(byte[], StateHandlerContext) to be called with the message contents.

Parameters:

context - the execution context

processMessage

default void processMessage(byte[] msg,
                            StateHandlerContext context)

Called after StateHandlerContext.processMessage().

Parameters:

msg - the raw message bytes

context - the execution context

onTimeoutExpired

default void onTimeoutExpired(SpecifiedTimeout kind,
                              StateHandlerContext context)

Called when a previously started timeout expires.

Parameters:

kind - which timeout expired

getExtraDataType

default java.lang.Class<?> getExtraDataType()