org.apache.commons.compress.compressors.z._internal_

Class InternalLZWInputStream

java.lang.Object

java.io.InputStream

org.apache.commons.compress.compressors.CompressorInputStream

org.apache.commons.compress.compressors.z._internal_.InternalLZWInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

Direct Known Subclasses:

ZCompressorInputStream

public abstract class InternalLZWInputStream
extends CompressorInputStream

This class is only public for technical reasons and is not part of Commons Compress' published API - it may change or disappear without warning.

Base-class for traditional Unix ".Z" compression and the Unshrinking method of ZIP archive.

Since:

1.7

Field Summary

Fields

Modifier and Type	Field and Description
protected int	bitsCached
protected int	bitsCachedSize
protected byte[]	characters
protected int	clearCode
protected int	codeSize
protected java.io.InputStream	in
protected int[]	prefixes
protected int	previousCode
protected int	tableSize

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	InternalLZWInputStream(java.io.InputStream inputStream)

Method Summary

Modifier and Type	Method and Description
protected abstract int	addEntry(int previousCode, byte character) Add a new entry to the dictionary.
protected int	addEntry(int previousCode, byte character, int maxTableSize) Adds a new entry if the maximum table size hasn't been exceeded and returns the new index.
protected int	addRepeatOfPreviousCode() Add entry for repeat of previousCode we haven't added, yet.
void	close()
protected abstract int	decompressNextSymbol() Read the next code and expand it.
protected int	expandCodeToOutputStack(int code, boolean addedUnfinishedEntry) Expands the entry with index code to the output stack and may create a new entry
protected void	initializeTables(int maxCodeSize) Initializes the arrays based on the maximum code size.
int	read()
int	read(byte[] b, int off, int len)
protected int	readNextCode() Reads the next code from the stream.
protected void	setClearCode(int codeSize) Sets the clear code based on the code size.

Methods inherited from class org.apache.commons.compress.compressors.CompressorInputStream

count, count, getBytesRead, getCount, pushedBackBytes

Methods inherited from class java.io.InputStream

available, mark, markSupported, read, reset, skip

Methods inherited from class java.lang.Object

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

Field Detail

in

protected final java.io.InputStream in

clearCode

protected int clearCode

codeSize

protected int codeSize

bitsCached

protected int bitsCached

bitsCachedSize

protected int bitsCachedSize

previousCode

protected int previousCode

tableSize

protected int tableSize

prefixes

protected int[] prefixes

characters

protected byte[] characters

Constructor Detail

InternalLZWInputStream

protected InternalLZWInputStream(java.io.InputStream inputStream)

Method Detail

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException

read

public int read()
         throws java.io.IOException

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException

read

public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException

decompressNextSymbol

protected abstract int decompressNextSymbol()
                                     throws java.io.IOException

Read the next code and expand it.

Throws:

java.io.IOException

addEntry

protected abstract int addEntry(int previousCode,
                                byte character)
                         throws java.io.IOException

Add a new entry to the dictionary.

Throws:

java.io.IOException

setClearCode

protected void setClearCode(int codeSize)

Sets the clear code based on the code size.

initializeTables

protected void initializeTables(int maxCodeSize)

Initializes the arrays based on the maximum code size.

readNextCode

protected int readNextCode()
                    throws java.io.IOException

Reads the next code from the stream.

Throws:

java.io.IOException

addEntry

protected int addEntry(int previousCode,
                       byte character,
                       int maxTableSize)

Adds a new entry if the maximum table size hasn't been exceeded and returns the new index.

addRepeatOfPreviousCode

protected int addRepeatOfPreviousCode()
                               throws java.io.IOException

Add entry for repeat of previousCode we haven't added, yet.

Throws:

java.io.IOException

expandCodeToOutputStack

protected int expandCodeToOutputStack(int code,
                                      boolean addedUnfinishedEntry)
                               throws java.io.IOException

Expands the entry with index code to the output stack and may create a new entry

Throws:

java.io.IOException