org.apache.stratos.messaging.domain.topology.lifecycle

Class LifeCycleStateManager<T extends LifeCycleState>

java.lang.Object

org.apache.stratos.messaging.domain.topology.lifecycle.LifeCycleStateManager<T>

All Implemented Interfaces:

Serializable

public class LifeCycleStateManager<T extends LifeCycleState>
extends Object
implements Serializable

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
LifeCycleStateManager(T initialState, String identifier)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	changeState(T nextState) Changes the current state to nextState, if nextState is not as same as the current state
T	getCurrentState() Get the current state
String	getIdentifier()
T	getPreviousState() Retrieves the previous state
Stack<T>	getStateStack() Get all the states this element has gone through
<S extends TopologyEvent> boolean	isPreConditionsValid(T nextState, S topologyEvent) checks if any conditions that should be met for the state transfer is valid
boolean	isStateTransitionValid(T nextState) Checks if the state transition is valid

Methods inherited from class java.lang.Object

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

Constructor Detail

LifeCycleStateManager

public LifeCycleStateManager(T initialState,
                     String identifier)

Method Detail

isPreConditionsValid

public <S extends TopologyEvent> boolean isPreConditionsValid(T nextState,
                                                     S topologyEvent)

checks if any conditions that should be met for the state transfer is valid

Type Parameters:

S - subclass of Topology event

Parameters:

nextState - possible next state for the topology element

topologyEvent - relevant ToplogyEvent

Returns:

true if preconditions are valid and satisfied, else false

isStateTransitionValid

public boolean isStateTransitionValid(T nextState)

Checks if the state transition is valid

Parameters:

nextState - possible next state for the topology element

Returns:

true if transitioning for nextState from current state is valid, else false

changeState

public boolean changeState(T nextState)

Changes the current state to nextState, if nextState is not as same as the current state

Parameters:

nextState - the next state to change

Returns:

true if current state changed to nextState, else false. Returns false if a state transitions to the same state (currentState = nextState).

getStateStack

public Stack<T> getStateStack()

Get all the states this element has gone through

Returns:

Stack of states

getCurrentState

public T getCurrentState()

Get the current state

Returns:

the current state

getPreviousState

public T getPreviousState()

Retrieves the previous state

Returns:

previous state

getIdentifier

public String getIdentifier()