org.springframework.data.hadoop.store.input
Class AbstractDataStreamReader.ReaderHelper<T,V>

java.lang.Object
  org.springframework.data.hadoop.store.input.AbstractDataStreamReader.ReaderHelper<T,V>

Type Parameters:

T - the type of reader

V - the type of data returned by reader

Enclosing class:

AbstractDataStreamReader

protected abstract static class AbstractDataStreamReader.ReaderHelper<T,V>
extends java.lang.Object

Reader helper hiding complexity of working with input streams.

Constructor Summary

protected

AbstractDataStreamReader.ReaderHelper(StreamsHolder<java.io.InputStream> streamsHolder, InputContext inputContext, Split split, CodecInfo codec) Instantiates a new reader helper.

Method Summary

protected abstract T	createReader(java.io.InputStream inputStream) Creates the reader.
protected abstract V	doRead(T delegate) Do read.
protected InputContext	getContext() Gets the wrapped InputContext.
protected StreamsHolder<java.io.InputStream>	getHolder() Gets the StreamsHolder for wrapped input stream.
protected T	getReader() Gets the reader created by createReader(InputStream).
protected void	init() Inits the reader helper.
protected void	processReadCount(int readSize) Processing a count of bytes read from a stream.
protected V	read() Reads a data by delegating to a reader.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractDataStreamReader.ReaderHelper

protected AbstractDataStreamReader.ReaderHelper(StreamsHolder<java.io.InputStream> streamsHolder,
                                                InputContext inputContext,
                                                Split split,
                                                CodecInfo codec)

Instantiates a new reader helper.

Parameters:

streamsHolder - the streams holder

inputContext - the input context

split - the input split

codec - the compression codec info

Method Detail

createReader

protected abstract T createReader(java.io.InputStream inputStream)
                           throws java.io.IOException

Creates the reader.

Parameters:

inputStream - the input stream

Returns:

the reader

Throws:

java.io.IOException - Signals that an I/O exception has occurred.

doRead

protected abstract V doRead(T delegate)
                     throws java.io.IOException

Do read.

Parameters:

delegate - the delegate reader

Returns:

the data read by a reader

Throws:

java.io.IOException - Signals that an I/O exception has occurred.

init

protected void init()
             throws java.io.IOException

Inits the reader helper. This method must be called by an implementor.

Throws:

java.io.IOException - Signals that an I/O exception has occurred.

processReadCount

protected void processReadCount(int readSize)
                         throws java.io.IOException

Processing a count of bytes read from a stream. Internally we're may use Seekable depending if it has been set.

Parameters:

readSize - the read size

Throws:

java.io.IOException - Signals that an I/O exception has occurred.

read

protected V read()
          throws java.io.IOException

Reads a data by delegating to a reader.

Returns:

the data read by a reader

Throws:

java.io.IOException - Signals that an I/O exception has occurred.

getReader

protected T getReader()

Gets the reader created by createReader(InputStream).

Returns:

the reader

getHolder

protected StreamsHolder<java.io.InputStream> getHolder()

Gets the StreamsHolder for wrapped input stream.

Returns:

the streams holder

getContext

protected InputContext getContext()

Gets the wrapped InputContext.

Returns:

the input context