com.prosysopc.ua.stack.utils

Class AbstractState<T,E extends Throwable>

java.lang.Object

com.prosysopc.ua.stack.utils.AbstractState<T,E>

All Implemented Interfaces:

IStatefulObject<T,E>

Direct Known Subclasses:

AbstractServerConnection, AbstractServerSecureChannel, AsyncRead, AsyncServerSocket, AsyncSocketImpl, AsyncWrite, BufferMonitor, HttpsServer, HttpsServerConnection, OpcTcpServer, State

public abstract class AbstractState<T,E extends Throwable>
extends Object
implements IStatefulObject<T,E>

This is a default implementation to IStatefulObject. The state type is parameterized (typically an enumeration).

See Also:

IStatefulObject, Listener for state modifications

Constructor Summary

Constructors

Constructor and Description
AbstractState(T initialState) Constructor for AbstractState.
AbstractState(T initialState, T errorState) Creates a state with a error state.

Method Summary

Modifier and Type	Method and Description
void	addStateListener(StateListener<T> listener) Adds on-event state listener.
void	addStateNotifiable(StateListener<T> listener) Add post-event notification listener.
protected T	attemptSetState(Set<T> prerequisiteState, T newState) Attempts to change the state.
protected void	clearError() clearError.
E	getError() Get error state or null.
T	getState() getState.
boolean	hasError() hasError.
protected boolean	isStateTransitionAllowed(T oldState, T newState) Checks whether state transition is allowed.
protected void	onListenerException(RuntimeException rte) Override this.
protected void	onStateTransition(T oldState, T newState) Override this.
void	removeStateListener(StateListener<T> listener) removeStateListener.
void	removeStateNotifiable(StateListener<T> listener) removeStateNotifiable.
protected void	setError(E error) setError.
protected boolean	setState(T state) Setter for the field state.
protected T	setState(T state, Executor listenerExecutor, Set<T> prerequisiteStates) Set state.
protected void	throwIfError() assertNoError.
T	waitForState(Set<T> set) Wait until state changes to one of the given states.
T	waitForState(Set<T> set, long timeout, TimeUnit unit) Wait until state changes to one of the given states or until time out occurs.
T	waitForStateUninterruptibly(Set<T> set) Wait until state changes to one of the given states.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractState

public AbstractState(T initialState)

Constructor for AbstractState.

Parameters:

initialState - a StateType object.

AbstractState

public AbstractState(T initialState,
                     T errorState)

Creates a state with a error state. The state object goes to errorState on setError().

Parameters:

initialState - a StateType object.

errorState - a StateType object.

Method Detail

addStateListener

public void addStateListener(StateListener<T> listener)

Adds on-event state listener.

Specified by:

addStateListener in interface IStatefulObject<T,E extends Throwable>

Parameters:

listener - a StateListener object.

addStateNotifiable

public void addStateNotifiable(StateListener<T> listener)

Add post-event notification listener. The prosessing thread is random. The prosessing order is not guaranteed if the handling is not synchronized.

Specified by:

addStateNotifiable in interface IStatefulObject<T,E extends Throwable>

Parameters:

listener - a StateListener object.

getError

public E getError()

Description copied from interface: IStatefulObject

Get error state or null.

Specified by:

getError in interface IStatefulObject<T,E extends Throwable>

Returns:

error

getState

public T getState()

Description copied from interface: IStatefulObject

getState.

Specified by:

getState in interface IStatefulObject<T,E extends Throwable>

Returns:

a StateType object.

hasError

public boolean hasError()

hasError.

Returns:

a boolean.

removeStateListener

public void removeStateListener(StateListener<T> listener)

Description copied from interface: IStatefulObject

removeStateListener.

Specified by:

removeStateListener in interface IStatefulObject<T,E extends Throwable>

Parameters:

listener - a StateListener object.

removeStateNotifiable

public void removeStateNotifiable(StateListener<T> listener)

Description copied from interface: IStatefulObject

removeStateNotifiable.

Specified by:

removeStateNotifiable in interface IStatefulObject<T,E extends Throwable>

Parameters:

listener - a StateListener object.

waitForState

public T waitForState(Set<T> set)
               throws InterruptedException,
                      E extends Throwable

Description copied from interface: IStatefulObject

Wait until state changes to one of the given states.

Specified by:

waitForState in interface IStatefulObject<T,E extends Throwable>

Parameters:

set - states that ends waiting

Returns:

the state in the given set that broke the wait

Throws:

InterruptedException - if any.

E - if any.

E extends Throwable

waitForState

public T waitForState(Set<T> set,
                      long timeout,
                      TimeUnit unit)
               throws InterruptedException,
                      TimeoutException,
                      E extends Throwable

Description copied from interface: IStatefulObject

Wait until state changes to one of the given states or until time out occurs.

Specified by:

waitForState in interface IStatefulObject<T,E extends Throwable>

Parameters:

set - a Set object.

timeout - a long.

unit - a TimeUnit object.

Returns:

state one in set

Throws:

InterruptedException - thread was interrupted

TimeoutException - timeout occured

E - if any.

E extends Throwable

waitForStateUninterruptibly

public T waitForStateUninterruptibly(Set<T> set)
                              throws E extends Throwable

Description copied from interface: IStatefulObject

Wait until state changes to one of the given states.

Specified by:

waitForStateUninterruptibly in interface IStatefulObject<T,E extends Throwable>

Parameters:

set - states that ends waiting

Returns:

the state in the given set that broke the wait

Throws:

E - if any.

E extends Throwable

attemptSetState

protected T attemptSetState(Set<T> prerequisiteState,
                            T newState)

Attempts to change the state. The state will be changed only if current state is one of the expected states.

Parameters:

prerequisiteState - expected current state

newState - a StateType object.

Returns:

state after attempt

clearError

protected void clearError()

clearError.

isStateTransitionAllowed

protected boolean isStateTransitionAllowed(T oldState,
                                           T newState)

Checks whether state transition is allowed. Override this

Parameters:

oldState - a StateType object.

newState - a StateType object.

Returns:

true if state transition is allowed

onListenerException

protected void onListenerException(RuntimeException rte)

Override this.

Parameters:

rte - a RuntimeException object.

onStateTransition

protected void onStateTransition(T oldState,
                                 T newState)

Override this.

Parameters:

oldState - a StateType object.

newState - a StateType object.

setError

protected void setError(E error)

setError.

Parameters:

error - a ErrorType object.

setState

protected boolean setState(T state)

Setter for the field state.

Parameters:

state - a StateType object.

Returns:

a boolean.

setState

protected T setState(T state,
                     Executor listenerExecutor,
                     Set<T> prerequisiteStates)

Set state.

Parameters:

state - a StateType object.

listenerExecutor - executor for post listener handling or null for immediate

prerequisiteStates - old state prerequisite or null

Returns:

state after attempt

throwIfError

protected void throwIfError()
                     throws E extends Throwable

assertNoError.

Throws:

E - if any.

E extends Throwable