com.atlassian.jira.util
Class XmlReader

java.lang.Object
  java.io.Reader
      com.atlassian.jira.util.XmlReader

All Implemented Interfaces:

Closeable, Readable

public final class XmlReader
extends Reader

This handles several XML-related tasks that normal java.io Readers don't support, inluding use of IETF standard encoding names and automatic detection of most XML encodings. The former is needed for interoperability; the latter is needed to conform with the XML spec. This class also optimizes reading some common encodings by providing low-overhead unsynchronized Reader support.

Note that the autodetection facility should be used only on data streams which have an unknown character encoding. For example, it should never be used on MIME text/xml entities.

Note that XML processors are only required to support UTF-8 and UTF-16 character encodings. Autodetection permits the underlying Java implementation to provide support for many other encodings, such as US-ASCII, ISO-8859-5, Shift_JIS, EUC-JP, and ISO-2022-JP.

Version:

$Revision: 1.3 $

Author:

David Brownell

Nested Class Summary

(package private) static class	XmlReader.AsciiReader
(package private) static class	XmlReader.BaseReader
(package private) static class	XmlReader.Iso8859_1Reader
(package private) static class	XmlReader.Utf8Reader

Field Summary

Fields inherited from class java.io.Reader

lock

Method Summary

void	close() Closes the reader.
static Reader	createReader(InputStream in) Constructs the reader from an input stream, autodetecting the encoding to use according to the heuristic specified in the XML 1.0 recommendation.
static Reader	createReader(InputStream in, String encoding) Creates a reader supporting the given encoding, mapping from standard encoding names to ones that understood by Java where necessary.
String	getEncoding() Returns the standard name of the encoding in use
InputStream	getInputStream()
void	mark(int value) Sets a mark allowing a limited number of characters to be "peeked", by reading and then resetting.
boolean	markSupported() Returns true iff the reader supports mark/reset.
int	read() Reads a single character.
int	read(char[] buf, int off, int len) Reads the number of characters read into the buffer, or -1 on EOF.
boolean	ready() Returns true iff input characters are known to be ready.
void	reset() Resets the current position to the last marked position.
long	skip(long value) Skips a specified number of characters.

Methods inherited from class java.io.Reader

read, read

Methods inherited from class java.lang.Object

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

Method Detail

createReader

public static Reader createReader(InputStream in)
                           throws IOException

Constructs the reader from an input stream, autodetecting the encoding to use according to the heuristic specified in the XML 1.0 recommendation.

Parameters:

in - the input stream from which the reader is constructed

Throws:

IOException - on error, such as unrecognized encoding

createReader

public static Reader createReader(InputStream in,
                                  String encoding)
                           throws IOException

Creates a reader supporting the given encoding, mapping from standard encoding names to ones that understood by Java where necessary.

Parameters:

in - the input stream from which the reader is constructed

encoding - the IETF standard name of the encoding to use; if null, autodetection is used.

Throws:

IOException - on error, including unrecognized encoding

getEncoding

public String getEncoding()

Returns the standard name of the encoding in use

getInputStream

public InputStream getInputStream()

read

public int read(char[] buf,
                int off,
                int len)
         throws IOException

Reads the number of characters read into the buffer, or -1 on EOF.

Specified by:

read in class Reader

Throws:

IOException

read

public int read()
         throws IOException

Reads a single character.

Overrides:

read in class Reader

Throws:

IOException

markSupported

public boolean markSupported()

Returns true iff the reader supports mark/reset.

Overrides:

markSupported in class Reader

mark

public void mark(int value)
          throws IOException

Sets a mark allowing a limited number of characters to be "peeked", by reading and then resetting.

Overrides:

mark in class Reader

Parameters:

value - how many characters may be "peeked".

Throws:

IOException

reset

public void reset()
           throws IOException

Resets the current position to the last marked position.

Overrides:

reset in class Reader

Throws:

IOException

skip

public long skip(long value)
          throws IOException

Skips a specified number of characters.

Overrides:

skip in class Reader

Throws:

IOException

ready

public boolean ready()
              throws IOException

Returns true iff input characters are known to be ready.

Overrides:

ready in class Reader

Throws:

IOException

close

public void close()
           throws IOException

Closes the reader.

Specified by:

close in interface Closeable

Specified by:

close in class Reader

Throws:

IOException