org.apache.nifi.processors.groovyx.flow

Class ProcessSessionWrap

java.lang.Object

org.apache.nifi.processors.groovyx.flow.ProcessSessionWrap

All Implemented Interfaces:

ProcessSession

Direct Known Subclasses:

GroovyProcessSessionWrap

public abstract class ProcessSessionWrap
extends Object
implements ProcessSession

wrapped session that collects all created/modified files if created with special flag and able to execute method revertReceivedTo(Relationship r, Throwable t) it will be good to create functionality with created file list and received file list in a standard session. Those file lists will simplify error management.

Field Summary

Fields

Modifier and Type	Field and Description
static String	ERROR_MESSAGE
static String	ERROR_STACKTRACE
private boolean	failureOnError
private ProcessSession	session
private Map<String,FlowFile>	toDrop
private List<FlowFile>	toFail

Constructor Summary

Constructors

Constructor and Description
ProcessSessionWrap(ProcessSession session, boolean toFailureOnError)

Method Summary

Modifier and Type	Method and Description
void	adjustCounter(String name, long delta, boolean immediate) Adjusts counter data for the given counter name and takes care of registering the counter if not already present.
SessionFile	append(FlowFile flowFile, OutputStreamCallback writer) Executes the given callback against the content corresponding to the given FlowFile, such that any data written to the OutputStream of the content will be appended to the end of FlowFile.
private void	assertNotSessionFile(FlowFile f)
void	clearState(Scope scope)
SessionFile	clone(FlowFile example) Creates a new FlowFile that is a clone of the given FlowFile as of the time this is called, both in content and attributes.
SessionFile	clone(FlowFile parent, long offset, long size) Creates a new FlowFile whose parent is the given FlowFile.
void	commit() Commits the current session ensuring all operations against FlowFiles within this session are atomically persisted.
void	commitAsync()
void	commitAsync(Runnable onSuccess, Consumer<Throwable> onFailure)
SessionFile	create() Creates a new FlowFile in the repository with no content and without any linkage to a parent FlowFile.
SessionFile	create(Collection<FlowFile> parents) Creates a new FlowFile in the repository with no content but with a parent linkage to the FlowFiles specified by the parents Collection.
SessionFile	create(FlowFile parent) Creates a new FlowFile in the repository with no content but with a parent linkage to parent.
void	exportTo(FlowFile flowFile, OutputStream destination) Writes the content of the given FlowFile to the given destination stream
void	exportTo(FlowFile flowFile, Path destination, boolean append) Writes the content of the given FlowFile to the given destination path.
SessionFile	get()
List<FlowFile>	get(FlowFileFilter filter) Returns all FlowFiles from all of the incoming queues for which the given FlowFileFilter indicates should be accepted.
List<FlowFile>	get(int maxResults) Returns up to maxResults FlowFiles from the work queue.
ProvenanceReporter	getProvenanceReporter() Returns a ProvenanceReporter that is tied to this ProcessSession.
QueueSize	getQueueSize()
StateMap	getState(Scope scope)
SessionFile	importFrom(InputStream source, FlowFile flowFile) Writes to the given FlowFile all content from the given content path.
SessionFile	importFrom(Path source, boolean keepSourceFile, FlowFile flowFile) Writes to the given FlowFile all content from the given content path.
SessionFile	merge(Collection<FlowFile> sources, FlowFile destination) Combines the content of all given source FlowFiles into a single given destination FlowFile.
SessionFile	merge(Collection<FlowFile> sources, FlowFile destination, byte[] header, byte[] footer, byte[] demarcator) Combines the content of all given source FlowFiles into a single given destination FlowFile.
void	migrate(ProcessSession newOwner)
void	migrate(ProcessSession newOwner, Collection<FlowFile> flowFiles)
private void	onClear()
private void	onDrop(Collection<FlowFile> ff)
private void	onDrop(FlowFile f) called when the file removed
private FlowFile	onGet(FlowFile f) called when got file from incoming queue
private List<FlowFile>	onGet(List<FlowFile> ff)
private FlowFile	onMod(FlowFile f) called when file created or modified
SessionFile	penalize(FlowFile flowFile) Sets a penalty for the given FlowFile which will make it unavailable to be operated on any further during the penalty period.
SessionFile	putAllAttributes(FlowFile flowFile, Map<String,String> attributes) Updates the given FlowFiles attributes with the given key/value pairs.
SessionFile	putAttribute(FlowFile flowFile, String key, String value) Updates the given FlowFiles attributes with the given key/value pair.
InputStream	read(FlowFile flowFile) Provides an InputStream that can be used to read the contents of the given FlowFile.
void	read(FlowFile flowFile, boolean allowSessionStreamManagement, InputStreamCallback reader) Executes the given callback against the contents corresponding to the given FlowFile.
void	read(FlowFile flowFile, InputStreamCallback reader) Executes the given callback against the contents corresponding to the given FlowFile.
void	remove(Collection<FlowFile> flowFiles) Ends the managed persistence for the given FlowFiles.
void	remove(FlowFile flowFile) Ends the managed persistence for the given FlowFile.
SessionFile	removeAllAttributes(FlowFile flowFile, Pattern keyPattern) Remove all attributes from the given FlowFile that have keys which match the given pattern.
SessionFile	removeAllAttributes(FlowFile flowFile, Set<String> keys) Removes the attributes with the given keys from the given FlowFile.
SessionFile	removeAttribute(FlowFile flowFile, String key) Removes the given FlowFile attribute with the given key.
boolean	replaceState(StateMap oldValue, Map<String,String> newValue, Scope scope)
void	revertReceivedTo(Relationship r, Throwable t) transfers all input files to relationship and drops other files.
void	rollback() Reverts any changes made during this session.
void	rollback(boolean penalize) Reverts any changes made during this session.
void	setState(Map<String,String> state, Scope scope)
void	transfer(Collection<FlowFile> flowFiles) Transfers the given FlowFiles back to the work queues from which the FlowFiles were pulled.
void	transfer(Collection<FlowFile> flowFiles, Relationship relationship) Transfers the given FlowFile to the appropriate destination processor work queue(s) based on the given relationship.
void	transfer(FlowFile flowFile) Transfers the given FlowFile back to the work queue from which it was pulled.
void	transfer(FlowFile flowFile, Relationship relationship) Transfers the given FlowFile to the appropriate destination processor work queue(s) based on the given relationship.
List<FlowFile>	unwrap(Collection<FlowFile> flowFiles)
FlowFile	unwrap(FlowFile f)
abstract SessionFile	wrap(FlowFile f) function returns wrapped flowfile with session for the simplified script access.
List<FlowFile>	wrap(List<FlowFile> ff)
OutputStream	write(FlowFile source) Provides an OutputStream that can be used to write to the contents of the given FlowFile.
SessionFile	write(FlowFile flowFile, OutputStreamCallback writer) Executes the given callback against the content corresponding to the given FlowFile.
SessionFile	write(FlowFile flowFile, StreamCallback writer) Executes the given callback against the content corresponding to the given flow file.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.nifi.processor.ProcessSession

commitAsync

Field Detail

ERROR_STACKTRACE

public static final String ERROR_STACKTRACE

See Also:

Constant Field Values

ERROR_MESSAGE

public static final String ERROR_MESSAGE

See Also:

Constant Field Values

session

private ProcessSession session

failureOnError

private boolean failureOnError

toFail

private List<FlowFile> toFail

toDrop

private Map<String,FlowFile> toDrop

Constructor Detail

ProcessSessionWrap

public ProcessSessionWrap(ProcessSession session,
                          boolean toFailureOnError)

Method Detail

wrap

public abstract SessionFile wrap(FlowFile f)

function returns wrapped flowfile with session for the simplified script access. The sample implementation: public SessionFile wrap(FlowFile f) { if (f == null) { return null; } if (f instanceof SessionFile) { return ((SessionFile) f); } return new SessionFile(this, f); }

wrap

public List<FlowFile> wrap(List<FlowFile> ff)

unwrap

public FlowFile unwrap(FlowFile f)

unwrap

public List<FlowFile> unwrap(Collection<FlowFile> flowFiles)

assertNotSessionFile

private void assertNotSessionFile(FlowFile f)

onMod

private FlowFile onMod(FlowFile f)

called when file created or modified

onGet

private FlowFile onGet(FlowFile f)

called when got file from incoming queue

onGet

private List<FlowFile> onGet(List<FlowFile> ff)

onDrop

private void onDrop(FlowFile f)

called when the file removed

onDrop

private void onDrop(Collection<FlowFile> ff)

onClear

private void onClear()

revertReceivedTo

public void revertReceivedTo(Relationship r,
                             Throwable t)

transfers all input files to relationship and drops other files.

Parameters:

r - where to transfer flow files, when null then transfers to input with penalize.

t - the cause why we do this transfer, when relationship specified then additional properties populated: ERROR_MESSAGE and ERROR_STACKTRACE.

commit

public void commit()

Commits the current session ensuring all operations against FlowFiles within this session are atomically persisted. All FlowFiles operated on within this session must be accounted for by transfer or removal or the commit will fail.

As soon as the commit completes the session is again ready to be used

Specified by:

commit in interface ProcessSession

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session.

FlowFileHandlingException - if not all FlowFiles acted upon within this session are accounted for by user code such that they have a transfer identified or where marked for removal. Automated rollback occurs.

ProcessException - if some general fault occurs while persisting the session. Initiates automatic rollback. The root cause can be obtained via Exception.getCause()

commitAsync

public void commitAsync()

Specified by:

commitAsync in interface ProcessSession

commitAsync

public void commitAsync(Runnable onSuccess,
                        Consumer<Throwable> onFailure)

Specified by:

commitAsync in interface ProcessSession

rollback

public void rollback()

Reverts any changes made during this session. All FlowFiles are restored back to their initial session state and back to their original queues. If this session is already committed or rolled back then no changes will occur. This method can be called any number of times. Calling this method is identical to calling rollback(boolean) passing false as the parameter.

Specified by:

rollback in interface ProcessSession

rollback

public void rollback(boolean penalize)

Reverts any changes made during this session. All FlowFiles are restored back to their initial session state and back to their original queues, after optionally being penalized. If this session is already committed or rolled back then no changes will occur. This method can be called any number of times.

Specified by:

rollback in interface ProcessSession

Parameters:

penalize - whether or not the FlowFiles that are being restored back to their queues should be penalized

adjustCounter

public void adjustCounter(String name,
                          long delta,
                          boolean immediate)

Adjusts counter data for the given counter name and takes care of registering the counter if not already present. The adjustment occurs only if and when the ProcessSession is committed.

Specified by:

adjustCounter in interface ProcessSession

Parameters:

name - the name of the counter

delta - the delta by which to modify the counter (+ or -)

immediate - if true, the counter will be updated immediately, without regard to whether the ProcessSession is commit or rolled back; otherwise, the counter will be incremented only if and when the ProcessSession is committed.

get

public SessionFile get()

Specified by:

get in interface ProcessSession

Returns:

FlowFile that is next highest priority FlowFile to process. Otherwise returns null.

get

public List<FlowFile> get(int maxResults)

Returns up to maxResults FlowFiles from the work queue. If no FlowFiles are available, returns an empty list. Will not return null. If multiple incoming queues are present, the behavior is unspecified in terms of whether all queues or only a single queue will be polled in a single call.

Specified by:

get in interface ProcessSession

Parameters:

maxResults - the maximum number of FlowFiles to return

Returns:

up to maxResults FlowFiles from the work queue. If no FlowFiles are available, returns an empty list. Will not return null.

Throws:

IllegalArgumentException - if maxResults is less than 0

get

public List<FlowFile> get(FlowFileFilter filter)

Returns all FlowFiles from all of the incoming queues for which the given FlowFileFilter indicates should be accepted. Calls to this method provide exclusive access to the underlying queues. I.e., no other thread will be permitted to pull FlowFiles from this Processor's queues or add FlowFiles to this Processor's incoming queues until this method call has returned.

Specified by:

get in interface ProcessSession

Parameters:

filter - to limit which flow files are returned

Returns:

all FlowFiles from all of the incoming queues for which the given FlowFileFilter indicates should be accepted.

getQueueSize

public QueueSize getQueueSize()

Specified by:

getQueueSize in interface ProcessSession

Returns:

the QueueSize that represents the number of FlowFiles and their combined data size for all FlowFiles waiting to be processed by the Processor that owns this ProcessSession, regardless of which Connection the FlowFiles live on

create

public SessionFile create()

Creates a new FlowFile in the repository with no content and without any linkage to a parent FlowFile. This method is appropriate only when data is received or created from an external system. Otherwise, this method should be avoided and should instead use create(FlowFile) or create(Collection).

When this method is used, a Provenance CREATE or RECEIVE Event should be generated. See the getProvenanceReporter() method and ProvenanceReporter class for more information

Specified by:

create in interface ProcessSession

Returns:

newly created FlowFile

create

public SessionFile create(FlowFile parent)

Creates a new FlowFile in the repository with no content but with a parent linkage to parent. The newly created FlowFile will inherit all of the parent's attributes except for the UUID. This method will automatically generate a Provenance FORK event or a Provenance JOIN event, depending on whether or not other FlowFiles are generated from the same parent before the ProcessSession is committed.

Specified by:

create in interface ProcessSession

Parameters:

parent - to base the new flowfile on

Returns:

newly created flowfile

create

public SessionFile create(Collection<FlowFile> parents)

Creates a new FlowFile in the repository with no content but with a parent linkage to the FlowFiles specified by the parents Collection. The newly created FlowFile will inherit all of the attributes that are in common to all parents (except for the UUID, which will be in common if only a single parent exists). This method will automatically generate a Provenance JOIN event.

Specified by:

create in interface ProcessSession

Parameters:

parents - which the new flowfile should inherit shared attributes from

Returns:

new flowfile

clone

public SessionFile clone(FlowFile example)

Creates a new FlowFile that is a clone of the given FlowFile as of the time this is called, both in content and attributes. This method automatically emits a Provenance CLONE Event.

Specified by:

clone in interface ProcessSession

Parameters:

example - FlowFile to be the source of cloning - given FlowFile must be a part of the given session

Returns:

FlowFile that is a clone of the given example

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be reference, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content

NullPointerException - if the argument null

clone

public SessionFile clone(FlowFile parent,
                         long offset,
                         long size)

Creates a new FlowFile whose parent is the given FlowFile. The content of the new FlowFile will be a subset of the byte sequence of the given FlowFile starting at the specified offset and with the length specified. The new FlowFile will contain all of the attributes of the original. This method automatically emits a Provenance FORK Event (or a Provenance CLONE Event, if the offset is 0 and the size is exactly equal to the size of the example FlowFile).

Specified by:

clone in interface ProcessSession

Parameters:

parent - to base the new flowfile attributes on

offset - of the parent flowfile to base the child flowfile content on

size - of the new flowfile from the offset

Returns:

a FlowFile with the specified size whose parent is first argument to this function

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session, or if the specified offset + size exceeds that of the size of the parent FlowFile. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be reference, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

penalize

public SessionFile penalize(FlowFile flowFile)

Sets a penalty for the given FlowFile which will make it unavailable to be operated on any further during the penalty period.

Specified by:

penalize in interface ProcessSession

Parameters:

flowFile - to penalize

Returns:

FlowFile the new FlowFile reference to use

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

NullPointerException - if the argument null

putAttribute

public SessionFile putAttribute(FlowFile flowFile,
                                String key,
                                String value)

Updates the given FlowFiles attributes with the given key/value pair. If the key is named uuid, this attribute will be ignored.

Specified by:

putAttribute in interface ProcessSession

Parameters:

flowFile - to update

key - of attribute

value - of attribute

Returns:

FlowFile the updated FlowFile

Throws:

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

NullPointerException - if an argument is null

putAllAttributes

public SessionFile putAllAttributes(FlowFile flowFile,
                                    Map<String,String> attributes)

Updates the given FlowFiles attributes with the given key/value pairs. If the map contains a key named uuid, this attribute will be ignored.

Specified by:

putAllAttributes in interface ProcessSession

Parameters:

flowFile - to update

attributes - the attributes to add to the given FlowFile

Returns:

FlowFile the updated FlowFile

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

NullPointerException - if an argument is null

removeAttribute

public SessionFile removeAttribute(FlowFile flowFile,
                                   String key)

Removes the given FlowFile attribute with the given key. If the key is named uuid, this method will return the same FlowFile without removing any attribute.

Specified by:

removeAttribute in interface ProcessSession

Parameters:

flowFile - to update

key - of attribute

Returns:

FlowFile the updated FlowFile

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

NullPointerException - if the argument null

removeAllAttributes

public SessionFile removeAllAttributes(FlowFile flowFile,
                                       Set<String> keys)

Removes the attributes with the given keys from the given FlowFile. If the set of keys contains the value uuid, this key will be ignored

Specified by:

removeAllAttributes in interface ProcessSession

Parameters:

flowFile - to update

keys - of attribute

Returns:

FlowFile the updated FlowFile

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

NullPointerException - if the argument null

removeAllAttributes

public SessionFile removeAllAttributes(FlowFile flowFile,
                                       Pattern keyPattern)

Remove all attributes from the given FlowFile that have keys which match the given pattern. If the pattern matches the key uuid, this key will not be removed.

Specified by:

removeAllAttributes in interface ProcessSession

Parameters:

flowFile - to update

keyPattern - may be null; if supplied is matched against each of the FlowFile attribute keys

Returns:

FlowFile containing only attributes which did not meet the key pattern

transfer

public void transfer(FlowFile flowFile,
                     Relationship relationship)

Transfers the given FlowFile to the appropriate destination processor work queue(s) based on the given relationship. If the relationship leads to more than one destination the state of the FlowFile is replicated such that each destination receives an exact copy of the FlowFile though each will have its own unique identity. The destination processors will not be able to operate on the given FlowFile until this session is committed or until the ownership of the session is migrated to another processor. If ownership of the session is passed to a destination processor then that destination processor will have immediate visibility of the transferred FlowFiles within the session.

Specified by:

transfer in interface ProcessSession

Parameters:

flowFile - to transfer

relationship - to transfer to

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

NullPointerException - if the argument null

IllegalArgumentException - if given relationship is not a known or registered relationship

transfer

public void transfer(FlowFile flowFile)

Transfers the given FlowFile back to the work queue from which it was pulled. The processor will not be able to operate on the given FlowFile until this session is committed. Any modifications that have been made to the FlowFile will be maintained. FlowFiles that are created by the processor cannot be transferred back to themselves via this method.

Specified by:

transfer in interface ProcessSession

Parameters:

flowFile - to transfer

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

IllegalArgumentException - if the FlowFile was created by this processor

NullPointerException - if the argument null

transfer

public void transfer(Collection<FlowFile> flowFiles)

Transfers the given FlowFiles back to the work queues from which the FlowFiles were pulled. The processor will not be able to operate on the given FlowFile until this session is committed. Any modifications that have been made to the FlowFile will be maintained. FlowFiles that are created by the processor cannot be transferred back to themselves via this method.

Specified by:

transfer in interface ProcessSession

Parameters:

flowFiles - to transfer

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFiles are already transferred or removed or don't belong to this session. Automatic rollback will occur.

IllegalArgumentException - if the FlowFile was created by this processor

NullPointerException - if the argument null

transfer

public void transfer(Collection<FlowFile> flowFiles,
                     Relationship relationship)

Transfers the given FlowFile to the appropriate destination processor work queue(s) based on the given relationship. If the relationship leads to more than one destination the state of the FlowFile is replicated such that each destination receives an exact copy of the FlowFile though each will have its own unique identity. The destination processors will not be able to operate on the given FlowFile until this session is committed or until the ownership of the session is migrated to another processor. If ownership of the session is passed to a destination processor then that destination processor will have immediate visibility of the transferred FlowFiles within the session.

Specified by:

transfer in interface ProcessSession

Parameters:

flowFiles - to transfer

relationship - to transfer to

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

NullPointerException - if the argument null

IllegalArgumentException - if given relationship is not a known or registered relationship

remove

public void remove(FlowFile flowFile)

Ends the managed persistence for the given FlowFile. The persistent attributes for the FlowFile are deleted and so is the content assuming nothing else references it and this FlowFile will no longer be available for further operation.

Specified by:

remove in interface ProcessSession

Parameters:

flowFile - to remove

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

remove

public void remove(Collection<FlowFile> flowFiles)

Ends the managed persistence for the given FlowFiles. The persistent attributes for the FlowFile are deleted and so is the content assuming nothing else references it and this FlowFile will no longer be available for further operation.

Specified by:

remove in interface ProcessSession

Parameters:

flowFiles - to remove

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if any of the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

read

public void read(FlowFile flowFile,
                 InputStreamCallback reader)
          throws FlowFileAccessException

Executes the given callback against the contents corresponding to the given FlowFile.

Specified by:

read in interface ProcessSession

Parameters:

flowFile - flow file to retrieve content of

reader - callback that will be called to read the flow file content

Throws:

FlowFileAccessException - if some IO problem occurs accessing FlowFile content; if an attempt is made to access the InputStream provided to the given InputStreamCallback after this method completed its execution

read

public InputStream read(FlowFile flowFile)

Provides an InputStream that can be used to read the contents of the given FlowFile. This method differs from those that make use of callbacks in that this method returns an InputStream and expects the caller to properly handle the lifecycle of the InputStream (i.e., the caller is responsible for ensuring that the InputStream is closed appropriately). The Process Session may or may not handle closing the stream when commit() or rollback() is called, but the responsibility of doing so belongs to the caller. The InputStream will throw an IOException if an attempt is made to read from the stream after the session is committed or rolled back.

Specified by:

read in interface ProcessSession

Parameters:

flowFile - the FlowFile to read

Returns:

an InputStream that can be used to read the contents of the FlowFile

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be referenced, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

read

public void read(FlowFile flowFile,
                 boolean allowSessionStreamManagement,
                 InputStreamCallback reader)
          throws FlowFileAccessException

Executes the given callback against the contents corresponding to the given FlowFile.

Note: The OutputStream provided to the given OutputStreamCallback will not be accessible once this method has completed its execution.

Specified by:

read in interface ProcessSession

Parameters:

flowFile - flow file to retrieve content of

allowSessionStreamManagement - allow session to hold the stream open for performance reasons

reader - that will be called to read the flow file content

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be reference, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content; if an attempt is made to access the InputStream provided to the given InputStreamCallback after this method completed its execution

merge

public SessionFile merge(Collection<FlowFile> sources,
                         FlowFile destination)

Combines the content of all given source FlowFiles into a single given destination FlowFile.

Specified by:

merge in interface ProcessSession

Parameters:

sources - the flowfiles to merge

destination - the flowfile to use as the merged result

Returns:

updated destination FlowFile (new size, etc...)

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

IllegalArgumentException - if the given destination is contained within the sources

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be reference, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content. The state of the destination will be as it was prior to this call.

merge

public SessionFile merge(Collection<FlowFile> sources,
                         FlowFile destination,
                         byte[] header,
                         byte[] footer,
                         byte[] demarcator)

Combines the content of all given source FlowFiles into a single given destination FlowFile.

Specified by:

merge in interface ProcessSession

Parameters:

sources - to merge together

destination - to merge to

header - bytes that will be added to the beginning of the merged output. May be null or empty.

footer - bytes that will be added to the end of the merged output. May be null or empty.

demarcator - bytes that will be placed in between each object merged together. May be null or empty.

Returns:

updated destination FlowFile (new size, etc...)

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

IllegalArgumentException - if the given destination is contained within the sources

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be reference, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content. The state of the destination will be as it was prior to this call.

write

public SessionFile write(FlowFile flowFile,
                         OutputStreamCallback writer)
                  throws FlowFileAccessException

Executes the given callback against the content corresponding to the given FlowFile.

Note: The OutputStream provided to the given OutputStreamCallback will not be accessible once this method has completed its execution.

Specified by:

write in interface ProcessSession

Parameters:

flowFile - to write to

writer - used to write new content

Returns:

updated FlowFile

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be referenced, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content; if an attempt is made to access the OutputStream provided to the given OutputStreamCallback after this method completed its execution

write

public SessionFile write(FlowFile flowFile,
                         StreamCallback writer)
                  throws FlowFileAccessException

Executes the given callback against the content corresponding to the given flow file.

Note: The InputStream & OutputStream provided to the given StreamCallback will not be accessible once this method has completed its execution.

Specified by:

write in interface ProcessSession

Parameters:

flowFile - to read from and write to

writer - used to read the old content and write new content

Returns:

updated FlowFile

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be reference, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content; if an attempt is made to access the InputStream or OutputStream provided to the given StreamCallback after this method completed its execution

append

public SessionFile append(FlowFile flowFile,
                          OutputStreamCallback writer)
                   throws FlowFileAccessException

Executes the given callback against the content corresponding to the given FlowFile, such that any data written to the OutputStream of the content will be appended to the end of FlowFile.

Note: The OutputStream provided to the given OutputStreamCallback will not be accessible once this method has completed its execution.

Specified by:

append in interface ProcessSession

Parameters:

flowFile - the flowfile for which content should be appended

writer - used to write new bytes to the flowfile content

Returns:

the updated flowfile reference for the new content

Throws:

FlowFileAccessException - if an attempt is made to access the OutputStream provided to the given OutputStreamCallback after this method completed its execution

importFrom

public SessionFile importFrom(Path source,
                              boolean keepSourceFile,
                              FlowFile flowFile)

Writes to the given FlowFile all content from the given content path.

Specified by:

importFrom in interface ProcessSession

Parameters:

source - the file from which content will be obtained

keepSourceFile - if true the content is simply copied; if false the original content might be used in a destructive way for efficiency such that the repository will have the data but the original data will be gone. If false the source object will be removed or gone once imported. It will not be restored if the session is rolled back so this must be used with caution. In some cases it can result in tremendous efficiency gains but is also dangerous.

flowFile - the FlowFile whose content will be updated

Returns:

the updated destination FlowFile (new size)

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be reference, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content

importFrom

public SessionFile importFrom(InputStream source,
                              FlowFile flowFile)

Writes to the given FlowFile all content from the given content path.

Specified by:

importFrom in interface ProcessSession

Parameters:

source - the file from which content will be obtained

flowFile - the FlowFile whose content will be updated

Returns:

the updated destination FlowFile (new size)

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be reference, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content

exportTo

public void exportTo(FlowFile flowFile,
                     Path destination,
                     boolean append)

Writes the content of the given FlowFile to the given destination path.

Specified by:

exportTo in interface ProcessSession

Parameters:

flowFile - to export the content of

destination - to export the content to

append - if true will append to the current content at the given path; if false will replace any current content

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be reference, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content

exportTo

public void exportTo(FlowFile flowFile,
                     OutputStream destination)

Writes the content of the given FlowFile to the given destination stream

Specified by:

exportTo in interface ProcessSession

Parameters:

flowFile - to export the content of

destination - to export the content to

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s)

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be reference, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content

getProvenanceReporter

public ProvenanceReporter getProvenanceReporter()

Returns a ProvenanceReporter that is tied to this ProcessSession.

Specified by:

getProvenanceReporter in interface ProcessSession

Returns:

the provenance reporter

migrate

public void migrate(ProcessSession newOwner)

Specified by:

migrate in interface ProcessSession

migrate

public void migrate(ProcessSession newOwner,
                    Collection<FlowFile> flowFiles)

Specified by:

migrate in interface ProcessSession

write

public OutputStream write(FlowFile source)

Provides an OutputStream that can be used to write to the contents of the given FlowFile.

Specified by:

write in interface ProcessSession

Parameters:

source - to write to

Returns:

an OutputStream that can be used to write to the contents of the FlowFile

Throws:

IllegalStateException - if detected that this method is being called from within a callback of another method in this session and for the given FlowFile(s), or if there is an open InputStream or OutputStream for the FlowFile's content (see read(FlowFile)).

FlowFileHandlingException - if the given FlowFile is already transferred or removed or doesn't belong to this session. Automatic rollback will occur.

MissingFlowFileException - if the given FlowFile content cannot be found. The FlowFile should no longer be referenced, will be internally destroyed, and the session is automatically rolled back and what is left of the FlowFile is destroyed.

FlowFileAccessException - if some IO problem occurs accessing FlowFile content; if an attempt is made to access the OutputStream provided to the given OutputStreamCallaback after this method completed its execution

setState

public void setState(Map<String,String> state,
                     Scope scope)
              throws IOException

Specified by:

setState in interface ProcessSession

Throws:

IOException

getState

public StateMap getState(Scope scope)
                  throws IOException

Specified by:

getState in interface ProcessSession

Throws:

IOException

replaceState

public boolean replaceState(StateMap oldValue,
                            Map<String,String> newValue,
                            Scope scope)
                     throws IOException

Specified by:

replaceState in interface ProcessSession

Throws:

IOException

clearState

public void clearState(Scope scope)
                throws IOException

Specified by:

clearState in interface ProcessSession

Throws:

IOException