com.northconcepts.datapipeline.memory

Class TailProxyReader

java.lang.Object

com.northconcepts.datapipeline.core.DataObject

com.northconcepts.datapipeline.core.Endpoint

com.northconcepts.datapipeline.core.DataEndpoint

com.northconcepts.datapipeline.core.DataReader

com.northconcepts.datapipeline.core.ProxyReader

com.northconcepts.datapipeline.memory.TailProxyReader

public class TailProxyReader
extends ProxyReader

Keeps the most recent n records in an in-memory RecordList which can be retrieved asynchronously while data is flowing through.

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.DataReader

fieldLineage, recordLineage

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
TailProxyReader(DataReader nestedDataReader, int maxRecords)

Method Summary

Modifier and Type	Method and Description
DataException	addExceptionProperties(DataException exception) Adds this endpoint's current state to a DataException.
int	getMaxRecords()
RecordList	getSnapshot()
protected Record	interceptRecord(Record record) Overridden by subclasses to transform, drop, or observe a record on its way through this proxy.

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

available, close, getNestedReader, map, map, open, readImpl, setNestedDataReader, setNestedDataReader

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

addLineage, getBufferSize, getNestedEndpoint, getReader, getRootEndpoint, getRootReader, isExhausted, isLineageSupported, isSaveLineage, peek, pop, push, read, setSaveLineage, skip

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

TailProxyReader

public TailProxyReader(DataReader nestedDataReader,
                       int maxRecords)

Method Detail

getMaxRecords

public int getMaxRecords()

getSnapshot

public RecordList getSnapshot()

interceptRecord

protected Record interceptRecord(Record record)
                          throws Throwable

Description copied from class: ProxyReader

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

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

• Return the record (possibly modified) to pass it downstream.
• Return null to drop the record; the framework reads the next one.
• Throw to fail the pipeline; the framework wraps the throwable in a DataException with .setRecord(record).
• The nested DataReader is opened and closed for you; do not read from it here.
• Do not call DataEndpoint.incrementRecordCount() here.

Overrides:

interceptRecord in class ProxyReader

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 ProxyReader