Package de.aristaflow.adept2.model.common.collection

Class TransformingRemoteIterator<S,T>

java.lang.Object

de.aristaflow.adept2.model.common.collection.AbstractRemoteIterator<S,T>

de.aristaflow.adept2.model.common.collection.TransformingRemoteIterator<S,T>

Type Parameters:

S - The type of objects that are retrieved from the wrapped remote iterator.

T - The type of objects that are returned by this remote iterator.

All Implemented Interfaces:

RemoteIterator<List<T>>, de.aristaflow.adept2.model.communication.ServerSideProxy, Closeable, AutoCloseable

public class TransformingRemoteIterator<S,T>
extends AbstractRemoteIterator<S,T>

This iterator wraps a remote iterator and transforms all objects before returning them using the provided transformator. It closes elements if appropriate depending on whether the wrapped iterator isForwardOnly().

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static final class	TransformingRemoteIterator.TransformingRemoteIteratorCloseTask	The clean-up task for closing the wrapped RemoteIterator.

Nested classes/interfaces inherited from interface de.aristaflow.adept2.model.communication.ServerSideProxy

de.aristaflow.adept2.model.communication.ServerSideProxy.LegacySspCloser, de.aristaflow.adept2.model.communication.ServerSideProxy.ServerSideProxyRemover

Field Summary

Fields

Modifier and Type	Field	Description
protected final RemoteIterator<List<S>>	iterator	The wrapped iterator providing the objects.

Fields inherited from class de.aristaflow.adept2.model.common.collection.AbstractRemoteIterator

cleanup, closeables, logger, transformator

Fields inherited from interface de.aristaflow.adept2.model.communication.ServerSideProxy

DEFAULT_ALIVE_TIME

Constructor Summary

Constructors

Constructor	Description
TransformingRemoteIterator(RemoteIterator<List<S>> iterator, Function<S,T> transformator)	Deprecated, for removal: This API element is subject to removal in a future version. Use TransformingRemoteIterator(RemoteIterator, Function, Logger) instead.
TransformingRemoteIterator(RemoteIterator<List<S>> iterator, Function<S,T> transformator, Logger logger)	Creates a new remote iterator that wraps the designated remote iterator and transforms all objects before returning them using the designated transformator.

Method Summary

Modifier and Type	Method	Description
void	close()	Explicitly closes this iterator which allows to release occupied memory and resources.
protected List<S>	getAllImpl()	Implements AbstractRemoteIterator.getAll() without the need to consider result transformation, closeable and alive time tracking.
protected List<S>	getNextImpl(int count)	Implements AbstractRemoteIterator.getNext(int) without the need to consider result transformation, closeable and alive time tracking.
protected List<S>	getNextImpl(int count, int start)	Implements AbstractRemoteIterator.getNext(int, int) without the need to consider result transformation, closeable and alive time tracking.
protected List<S>	getPreviousImpl(int count)	Implements AbstractRemoteIterator.getPrevious(int) without the need to consider result transformation, closeable and alive time tracking.
long	getRemainingAliveTime()	Gets the time in milliseconds this iterator will still be valid and does allow access to the underlying data.
protected boolean	isClosed()	Gets whether this remote iterator has been closed and its data is not available any more.
boolean	isForwardOnly()	Gets whether this iterator only allows iterating in forward direction, that is calls to RemoteIterator.getNext(int) but not to RemoteIterator.getNext(int, int) and RemoteIterator.getPrevious(int).
boolean	isSnapshot()	Gets whether this iterator is a snapshot and therefore its contents is not subject of change while iterating.
long	keepAlive(long aliveTime)	Keeps this iterator alive for the designated time span (in milliseconds).

Methods inherited from class de.aristaflow.adept2.model.common.collection.AbstractRemoteIterator

aboutToReturn, closeOnTraversal, enter, exit, getAll, getNext, getNext, getPrevious, setCloseOnTraversal

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.aristaflow.adept2.model.common.collection.RemoteIterator

drop

Field Details

iterator

protected final RemoteIterator<List<S>> iterator

The wrapped iterator providing the objects.

Constructor Details

TransformingRemoteIterator

@Deprecated(since="15.0.0",
            forRemoval=true)
public TransformingRemoteIterator(RemoteIterator<List<S>> iterator,
 Function<S,T> transformator)

Deprecated, for removal: This API element is subject to removal in a future version.

Use TransformingRemoteIterator(RemoteIterator, Function, Logger) instead.

Creates a new remote iterator that wraps the designated remote iterator and transforms all objects before returning them using the designated transformator.

Parameters:

iterator - The wrapped iterator providing the objects. The RemoteIterator will be coupled to this TransformingRemoteIterator, so do not close it; clone it if required longer than this TransformingRemoteIterator.

transformator - The transformator transforming the objects before retrieval.

TransformingRemoteIterator

public TransformingRemoteIterator(RemoteIterator<List<S>> iterator,
 Function<S,T> transformator,
 Logger logger)

Creates a new remote iterator that wraps the designated remote iterator and transforms all objects before returning them using the designated transformator.

Parameters:

iterator - The wrapped iterator providing the objects. The RemoteIterator will be coupled to this TransformingRemoteIterator, so do not close it; clone it if required longer than this TransformingRemoteIterator.

transformator - The transformator transforming the objects before retrieval.

logger - The logger for logging messages instead of throwing exceptions.

Method Details

isClosed

protected boolean isClosed()

Description copied from class: AbstractRemoteIterator

Gets whether this remote iterator has been closed and its data is not available any more.

Specified by:

isClosed in class AbstractRemoteIterator<S,T>

Returns:

Whether this remote iterator has been closed and its data is not available any more.

getNextImpl

protected List<S> getNextImpl(int count)
                       throws DataSourceException,
DataConsistencyException

Description copied from class: AbstractRemoteIterator

Implements AbstractRemoteIterator.getNext(int) without the need to consider result transformation, closeable and alive time tracking.

Specified by:

getNextImpl in class AbstractRemoteIterator<S,T>

Throws:

DataSourceException

DataConsistencyException

getNextImpl

protected List<S> getNextImpl(int count,
 int start)
                       throws DataSourceException,
DataConsistencyException

Description copied from class: AbstractRemoteIterator

Implements AbstractRemoteIterator.getNext(int, int) without the need to consider result transformation, closeable and alive time tracking.

Specified by:

getNextImpl in class AbstractRemoteIterator<S,T>

Throws:

DataSourceException

DataConsistencyException

getPreviousImpl

protected List<S> getPreviousImpl(int count)
                           throws DataSourceException,
DataConsistencyException

Description copied from class: AbstractRemoteIterator

Implements AbstractRemoteIterator.getPrevious(int) without the need to consider result transformation, closeable and alive time tracking.

Specified by:

getPreviousImpl in class AbstractRemoteIterator<S,T>

Throws:

DataSourceException

DataConsistencyException

getAllImpl

protected List<S> getAllImpl()
                      throws DataSourceException,
DataConsistencyException

Description copied from class: AbstractRemoteIterator

Implements AbstractRemoteIterator.getAll() without the need to consider result transformation, closeable and alive time tracking.

Specified by:

getAllImpl in class AbstractRemoteIterator<S,T>

Throws:

DataSourceException

DataConsistencyException

isSnapshot

public boolean isSnapshot()
                   throws DataSourceException

Description copied from interface: RemoteIterator

Gets whether this iterator is a snapshot and therefore its contents is not subject of change while iterating. However, the contents may be outdated while iterating.

Returns:

Whether this iterator is a snapshot providing stable but maybe outdated data.

Throws:

DataSourceException - If there are problems accessing the underlying data source, a DataSourceException will be thrown.

isForwardOnly

public boolean isForwardOnly()
                      throws DataSourceException

Description copied from interface: RemoteIterator

Gets whether this iterator only allows iterating in forward direction, that is calls to RemoteIterator.getNext(int) but not to RemoteIterator.getNext(int, int) and RemoteIterator.getPrevious(int). This can be restricted by the underlying data structure, for instance a ResultSet.

Returns:

Whether this iterator only allows iterating in forward direction.

Throws:

DataSourceException - If there are problems accessing the underlying data source, a DataSourceException will be thrown.

getRemainingAliveTime

public long getRemainingAliveTime()

Description copied from interface: RemoteIterator

Gets the time in milliseconds this iterator will still be valid and does allow access to the underlying data. Afterwards the iterator will be closed automatically to save memory and resources.
A negative value indicates a closed iterator. Such an iterator cannot be kept alive. Note that this alive time does not need to correspond to the original alive time requested

Returns:

The time this iterator remains valid and can be used. Afterwards the iterator will be closed. Long.MIN_VALUE for an already closed remote iterator.

keepAlive

public long keepAlive(long aliveTime)
               throws IOException

Description copied from interface: RemoteIterator

Keeps this iterator alive for the designated time span (in milliseconds). This allows to continue using this iterator. However, note that extending the usage time significantly impacts resource occupation.
Note that extending the time need not be successful. The underlying iterator implementation may not be able to extend the alive time of all used resource, for instance pooled database connections.

A 0 or a negative value is equal to closed this iterator.

Parameters:

aliveTime - The time in milliseconds to keep this iterator alive that is not to close it automatically.

Returns:

The relative time this iterator will be kept alive longer. 0 indicates immediate closing. A negative value represents the failure of extending the alive time, check RemoteIterator.getRemainingAliveTime() in this case whether extending the keep alive time has been successful or not.

Throws:

IOException - If there are problems accessing the underlying data source, an IOException will be thrown.

close

public void close()
           throws IOException

Description copied from interface: RemoteIterator

Explicitly closes this iterator which allows to release occupied memory and resources. Closing will be done implicitly after the alive time has elapsed.
This method may be called several times. Implementors have to take care of this.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface RemoteIterator<S>

Specified by:

close in interface de.aristaflow.adept2.model.communication.ServerSideProxy

Overrides:

close in class AbstractRemoteIterator<S,T>

Throws:

IOException - If there are problems accessing the underlying data source, an IOException will be thrown.