Class XMLEncodingDetector.RewindableInputStream

java.lang.Object

java.io.InputStream

org.apache.jasper.xmlparser.XMLEncodingDetector.RewindableInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

Enclosing class:

XMLEncodingDetector

private final class XMLEncodingDetector.RewindableInputStream
extends InputStream

This class wraps the byte inputstreams we're presented with. We need it because java.io.InputStreams don't provide functionality to reread processed bytes, and they have a habit of reading more than one character when you call their read() methods. This means that, once we discover the true (declared) encoding of a document, we can neither backtrack to read the whole doc again nor start reading where we are with a new reader. This class allows rewinding an inputStream by allowing a mark to be set, and the stream reset to that position. The class assumes that it needs to read one character per invocation when it's read() method is inovked, but uses the underlying InputStream's read(char[], offset length) method--it won't buffer data read this way!

Field Summary

Fields

Modifier and Type	Field	Description
private byte[]	fData
private int	fEndOffset
private InputStream	fInputStream
private int	fLength
private int	fMark
private int	fOffset
private int	fStartOffset

Constructor Summary

Constructors

Constructor	Description
RewindableInputStream(InputStream is)

Method Summary

Modifier and Type	Method	Description
int	available()
void	close()
void	mark(int howMuch)
boolean	markSupported()
int	read()
int	read(byte[] b, int off, int len)
void	reset()
void	rewind()
void	setStartOffset(int offset)
long	skip(long n)

Methods inherited from class InputStream

nullInputStream, read, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class Object

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

Field Details

fInputStream

private InputStream fInputStream

fData

private byte[] fData

fStartOffset

private int fStartOffset

fEndOffset

private int fEndOffset

fOffset

private int fOffset

fLength

private int fLength

fMark

private int fMark

Constructor Details

RewindableInputStream

public RewindableInputStream(InputStream is)

Method Details

setStartOffset

public void setStartOffset(int offset)

rewind

public void rewind()

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

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

Overrides:

read in class InputStream

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class InputStream

Throws:

IOException

available

public int available()
              throws IOException

Overrides:

available in class InputStream

Throws:

IOException

mark

public void mark(int howMuch)

Overrides:

mark in class InputStream

reset

public void reset()

Overrides:

reset in class InputStream

markSupported

public boolean markSupported()

Overrides:

markSupported in class InputStream

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException