net.pwall.pipeline.codec

Class DynamicDecoder<R>

java.lang.Object

net.pwall.pipeline.BaseAbstractAcceptor<R>

net.pwall.pipeline.AbstractIntAcceptor<R>

net.pwall.pipeline.AbstractIntPipeline<R>

net.pwall.pipeline.codec.SwitchableDecoder<R>

net.pwall.pipeline.codec.DynamicDecoder<R>

Type Parameters:

R - the "Result" class (may be Void)

All Implemented Interfaces:

AutoCloseable, IntConsumer, BaseAcceptor<R>, BasePipeline<R>, IntAcceptor<R>, IntPipeline<R>

public class DynamicDecoder<R>
extends SwitchableDecoder<R>

A dynamic decoding pipeline which attempts to determine the encoding of the data from its content.

Author:

Peter Wall

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DynamicDecoder.State

Field Summary

Fields

Modifier and Type	Field and Description
protected DynamicDecoder.State	state

Fields inherited from class net.pwall.pipeline.codec.SwitchableDecoder

delegate

Constructor Summary

Constructors

Constructor and Description
DynamicDecoder(IntAcceptor<? extends R> downstream) Construct a DynamicDecoder with the specified downstream IntAcceptor.
DynamicDecoder(IntAcceptor<? extends R> downstream, Charset charset) Construct a DynamicDecoder with the specified downstream IntAcceptor, switching immediately to the specified Charset if specified.

Method Summary

Modifier and Type	Method and Description
void	acceptInt(int value) Accept an int (after closed check and test for end of data).
void	close() Close the pipeline.
boolean	isStageComplete() Return true if all sequences in the input to this stage of the pipeline are complete, that is, the input is not in the middle of a sequence requiring more data.
void	switchTo(Charset charset) Switch to the nominated character set.
void	switchTo(IntAcceptor<? extends R> delegate) Switch to the specified delegate.
void	switchTo(String charsetName) Switch to the nominated character set.

Methods inherited from class net.pwall.pipeline.AbstractIntPipeline

emit, flush, getDownstream

Methods inherited from class net.pwall.pipeline.AbstractIntAcceptor

accept, accept

Methods inherited from class net.pwall.pipeline.BaseAbstractAcceptor

isClosed

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.pwall.pipeline.IntAcceptor

accept, accept, accept, accept, accept, accept, accept, accept, accept, accept

Methods inherited from interface java.util.function.IntConsumer

andThen

Methods inherited from interface net.pwall.pipeline.BasePipeline

getResult, isComplete

Methods inherited from interface net.pwall.pipeline.BaseAcceptor

isClosed, safeClose

Field Detail

state

protected DynamicDecoder.State state

Constructor Detail

DynamicDecoder

public DynamicDecoder(IntAcceptor<? extends R> downstream)

Construct a DynamicDecoder with the specified downstream IntAcceptor.

Parameters:

downstream - the downstream IntAcceptor

DynamicDecoder

public DynamicDecoder(IntAcceptor<? extends R> downstream,
                      Charset charset)

Construct a DynamicDecoder with the specified downstream IntAcceptor, switching immediately to the specified Charset if specified. This bypasses much of the functionality of the DynamicDecoder, but allowing the Charset to be specified in this way simplifies the creation of a decoder in those cases where the encoding may be, but is not always, known in advance.

Parameters:

downstream - the downstream IntAcceptor

charset - the Charset if known, or null to allow dynamic encoding determination

Method Detail

acceptInt

public void acceptInt(int value)

Accept an int (after closed check and test for end of data). This function operates as a "state machine", with much of the complexity involved in the examination of the first four characters of the stream to recognise big-endian and little-endian UTF-16 and UTF-32 encodings.

If the stream appears to consist of 8-bit characters, it is placed in an indeterminate state until a character above 0x80 is encountered, at which point the decoder will check whether the subsequent characters are consistent with a UTF-8 encoding sequence, in which case that encoding will be assumed for the remainder of the stream; otherwise the Windows-1252 encoding is assumed.

Overrides:

acceptInt in class SwitchableDecoder<R>

Parameters:

value - the input value

close

public void close()

Close the pipeline.

Specified by:

close in interface AutoCloseable

Overrides:

close in class AbstractIntPipeline<R>

isStageComplete

public boolean isStageComplete()

Return true if all sequences in the input to this stage of the pipeline are complete, that is, the input is not in the middle of a sequence requiring more data.

Specified by:

isStageComplete in interface BasePipeline<R>

Overrides:

isStageComplete in class SwitchableDecoder<R>

Returns:

true if the input is in the "complete" state

switchTo

public void switchTo(IntAcceptor<? extends R> delegate)

Switch to the specified delegate.

Overrides:

switchTo in class SwitchableDecoder<R>

Parameters:

delegate - the new delegate

switchTo

public void switchTo(Charset charset)

Switch to the nominated character set.

Overrides:

switchTo in class SwitchableDecoder<R>

Parameters:

charset - the Charset

switchTo

public void switchTo(String charsetName)

Switch to the nominated character set.

Overrides:

switchTo in class SwitchableDecoder<R>

Parameters:

charsetName - the character set name