com.northconcepts.datapipeline.core

Class ProxyWriter

java.lang.Object

com.northconcepts.datapipeline.core.DataObject

com.northconcepts.datapipeline.core.Endpoint

com.northconcepts.datapipeline.core.DataEndpoint

com.northconcepts.datapipeline.core.DataWriter

com.northconcepts.datapipeline.core.ProxyWriter

Direct Known Subclasses:

AsyncWriter, DebugWriter, IntegrationProxyWriter, JdbcMultiUpsertWriter, JdbcMultiWriter, MeteredWriter, PdfWriter, RetryingWriter, SequenceWriter, TransformingWriter

public class ProxyWriter
extends DataWriter

Abstract super-class for writing records to another DataWriter, possibly transforming them along the way. The only method that a subclass should implement is interceptRecord(Record).

Nested Class Summary

Nested classes/interfaces inherited from class com.northconcepts.datapipeline.core.DataEndpoint

DataEndpoint.State

Field Summary

Fields inherited from class com.northconcepts.datapipeline.core.DataEndpoint

lastRecord, PRODUCT, PRODUCT_VERSION, VENDOR, XML_INPUT_FACTORY_KEY

Fields inherited from class com.northconcepts.datapipeline.core.Endpoint

BUFFER_SIZE, captureElapsedTime, DEFAULT_READ_BUFFER_SIZE

Fields inherited from class com.northconcepts.datapipeline.core.DataObject

id, log, name, TIMESTAMP_FORMAT

Constructor Summary

Constructors

Constructor and Description
ProxyWriter(DataWriter nestedDataWriter)

Method Summary

Modifier and Type	Method and Description
DataException	addExceptionProperties(DataException exception) Adds this endpoint's current state to a DataException.
int	available() Returns the number of records that can probably be written without blocking.
void	close() Indicates that this endpoint has finished reading or writing.
DataWriter	getNestedWriter() Returns the DataWriter held inside this one or null if there isn't one.
protected Record	interceptRecord(Record record) Overridden by subclasses to transform, drop, or observe a record on its way through this proxy.
static ProxyWriter	map(DataWriter writer, BiFunction<ProxyWriter,Record,Record> mapper)
static ProxyWriter	map(DataWriter Writer, Function<Record,Record> mapper)
void	open() Makes this endpoint ready for reading or writing.
protected void	setNestedDataWriter(DataWriter nestedDataWriter) Make sure to close old target and open the new one or call setNestedDataWriter(DataWriter, boolean) with true.
protected void	setNestedDataWriter(DataWriter nestedDataWriter, boolean manageLifecycle)
protected void	writeImpl(Record record) Overridden by subclasses to write the specified record to this DataWriter.

Methods inherited from class com.northconcepts.datapipeline.core.DataWriter

getNestedEndpoint, getRootEndpoint, getRootWriter, getWriter, write

Methods inherited from class com.northconcepts.datapipeline.core.DataEndpoint

decrementRecordCount, enableJmx, getLastRecord, getRecordCount, getRecordCountAsBigInteger, getRecordCountAsString, incrementRecordCount, isRecordCountBigInteger, resetRecordCount, toString

Methods inherited from class com.northconcepts.datapipeline.core.Endpoint

addElapsedtime, assertClosed, assertNotOpened, assertOpened, finalize, getClosedOn, getDescription, getElapsedTime, getElapsedTimeAsString, getOpenedOn, getOpenElapsedTime, getOpenElapsedTimeAsString, getSelfTime, getSelfTimeAsString, getState, isCaptureElapsedTime, isClosed, isOpen, setCaptureElapsedTime, setDescription

Methods inherited from class com.northconcepts.datapipeline.core.DataObject

exception, exception, exception, getId, getName, resetID

Methods inherited from class java.lang.Object

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

Constructor Detail

ProxyWriter

public ProxyWriter(DataWriter nestedDataWriter)

Method Detail

map

public static ProxyWriter map(DataWriter Writer,
                              Function<Record,Record> mapper)
                       throws Throwable

Throws:

Throwable

map

public static ProxyWriter map(DataWriter writer,
                              BiFunction<ProxyWriter,Record,Record> mapper)
                       throws Throwable

Throws:

Throwable

getNestedWriter

public DataWriter getNestedWriter()

Description copied from class: DataWriter

Returns the DataWriter held inside this one or null if there isn't one.

Overrides:

getNestedWriter in class DataWriter

setNestedDataWriter

protected void setNestedDataWriter(DataWriter nestedDataWriter)

Make sure to close old target and open the new one or call setNestedDataWriter(DataWriter, boolean) with true.

setNestedDataWriter

protected void setNestedDataWriter(DataWriter nestedDataWriter,
                                   boolean manageLifecycle)
                            throws DataException

Throws:

DataException

available

public int available()
              throws DataException

Description copied from class: DataWriter

Returns the number of records that can probably be written without blocking.

Overrides:

available in class DataWriter

Throws:

DataException

open

public void open()
          throws DataException

Description copied from class: DataEndpoint

Makes this endpoint ready for reading or writing.

Overrides:

open in class DataEndpoint

Throws:

DataException

close

public void close()
           throws DataException

Description copied from class: DataEndpoint

Indicates that this endpoint has finished reading or writing.

Overrides:

close in class DataEndpoint

Throws:

DataException

interceptRecord

protected Record interceptRecord(Record record)
                          throws Throwable

Overridden by subclasses to transform, drop, or observe a record on its way through this proxy.

Contract for subclasses (see also docs/authoring/ProxyWriter.md):

• Return the record (possibly modified) to forward it to the nested DataWriter.
• Return null to drop the record; the framework will not write it downstream.
• Throw to fail the pipeline; the framework wraps the throwable in a DataException with .setRecord(record).
• The nested DataWriter is opened and closed for you; do not write to it here.
• Do not call DataEndpoint.incrementRecordCount() here.

Throws:

Throwable

writeImpl

protected void writeImpl(Record record)
                  throws Throwable

Description copied from class: DataWriter

Overridden by subclasses to write the specified record to this DataWriter.

Contract for subclasses (see also docs/authoring/DataWriter.md):

• Do not call this method directly — DataWriter.write(Record) is the template method that wraps exceptions, increments the record count, and attaches the offending record to thrown DataExceptions.
• Do not call DataEndpoint.incrementRecordCount() here; DataWriter.write(Record) already does.
• Throw raw exceptions; DataWriter.write(Record) wraps them via exception(throwable).setRecord(record).

Specified by:

writeImpl in class DataWriter

Throws:

Throwable

addExceptionProperties

public DataException addExceptionProperties(DataException exception)

Description copied from class: Endpoint

Adds this endpoint's current state to a DataException. Since this method is called whenever an exception is thrown, subclasses should override it to add their specific information.

Overrides:

addExceptionProperties in class DataWriter