com.northconcepts.datapipeline.core

Class LimitReader

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.core.LimitReader

public class LimitReader
extends ProxyReader

A proxy that can skip a number of upstream records, limit the number of records sent downstream, or both. This reader acts like the MySQL SELECT ... LIMIT offset, row_count statement.

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
LimitReader(DataReader targetDataReader)
LimitReader(DataReader targetDataReader, Integer offset, Integer limit)
LimitReader(DataReader targetDataReader, long limit)
LimitReader(DataReader targetDataReader, Long offset, Long limit)

Method Summary

Modifier and Type	Method and Description
DataException	addExceptionProperties(DataException exception) Adds this endpoint's current state to a DataException.
Long	getLimit()
Long	getOffset()
long	getOffsetConsumed()
void	open() Makes this endpoint ready for reading or writing.
protected Record	readImpl() Overridden by subclasses to read the next record from this DataReader.
LimitReader	setLimit(long limit)
LimitReader	setLimit(Long limit)
LimitReader	setOffset(long offset)
LimitReader	setOffset(Long offset)

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

available, close, getNestedReader, interceptRecord, map, map, 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

LimitReader

public LimitReader(DataReader targetDataReader)

LimitReader

public LimitReader(DataReader targetDataReader,
                   Long offset,
                   Long limit)

LimitReader

public LimitReader(DataReader targetDataReader,
                   Integer offset,
                   Integer limit)

LimitReader

public LimitReader(DataReader targetDataReader,
                   long limit)

Method Detail

getOffset

public Long getOffset()

setOffset

public LimitReader setOffset(Long offset)

setOffset

public LimitReader setOffset(long offset)

getLimit

public Long getLimit()

setLimit

public LimitReader setLimit(Long limit)

setLimit

public LimitReader setLimit(long limit)

getOffsetConsumed

public long getOffsetConsumed()

open

public void open()
          throws DataException

Description copied from class: DataEndpoint

Makes this endpoint ready for reading or writing.

Overrides:

open in class ProxyReader

Throws:

DataException

readImpl

protected Record readImpl()
                   throws Throwable

Description copied from class: DataReader

Overridden by subclasses to read the next record from this DataReader. The default implementation of DataReader.read() now insures that this method will not be called again after it returns a null.

If no record is available, null will be returned.

Overrides:

readImpl 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