com.sun.msv.scanner.dtd

Class XmlReader

java.lang.Object

java.io.Reader

com.sun.msv.scanner.dtd.XmlReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.lang.Readable

final class XmlReader
extends java.io.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:

1.3 00/02/24

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(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

Modifier and Type	Field and Description
private java.lang.String	assignedEncoding
private static java.util.Hashtable	charsets
private boolean	closed
private java.io.Reader	in
private static int	MAXPUSHBACK

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Modifier	Constructor and Description
private	XmlReader(java.io.InputStream stream)

Method Summary

Modifier and Type	Method and Description
void	close() Closes the reader.
static java.io.Reader	createReader(java.io.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 java.io.Reader	createReader(java.io.InputStream in, java.lang.String encoding) Creates a reader supporting the given encoding, mapping from standard encoding names to ones that understood by Java where necessary.
java.lang.String	getEncoding() Returns the standard name of the encoding in use
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.
private void	setEncoding(java.io.InputStream stream, java.lang.String encoding)
long	skip(long value) Skips a specified number of characters.
private static java.lang.String	std2java(java.lang.String encoding)
private void	useEncodingDecl(java.io.PushbackInputStream pb, java.lang.String encoding)

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

Field Detail

MAXPUSHBACK

private static final int MAXPUSHBACK

See Also:

Constant Field Values

in

private java.io.Reader in

assignedEncoding

private java.lang.String assignedEncoding

closed

private boolean closed

charsets

private static final java.util.Hashtable charsets

Constructor Detail

XmlReader

private XmlReader(java.io.InputStream stream)
           throws java.io.IOException

Throws:

java.io.IOException

Method Detail

createReader

public static java.io.Reader createReader(java.io.InputStream in)
                                   throws java.io.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:

java.io.IOException - on error, such as unrecognized encoding

createReader

public static java.io.Reader createReader(java.io.InputStream in,
                                          java.lang.String encoding)
                                   throws java.io.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:

java.io.IOException - on error, including unrecognized encoding

std2java

private static java.lang.String std2java(java.lang.String encoding)

getEncoding

public java.lang.String getEncoding()

Returns the standard name of the encoding in use

useEncodingDecl

private void useEncodingDecl(java.io.PushbackInputStream pb,
                             java.lang.String encoding)
                      throws java.io.IOException

Throws:

java.io.IOException

setEncoding

private void setEncoding(java.io.InputStream stream,
                         java.lang.String encoding)
                  throws java.io.IOException

Throws:

java.io.IOException

read

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

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

Specified by:

read in class java.io.Reader

Throws:

java.io.IOException

read

public int read()
         throws java.io.IOException

Reads a single character.

Overrides:

read in class java.io.Reader

Throws:

java.io.IOException

markSupported

public boolean markSupported()

Returns true iff the reader supports mark/reset.

Overrides:

markSupported in class java.io.Reader

mark

public void mark(int value)
          throws java.io.IOException

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

Overrides:

mark in class java.io.Reader

Parameters:

value - how many characters may be "peeked".

Throws:

java.io.IOException

reset

public void reset()
           throws java.io.IOException

Resets the current position to the last marked position.

Overrides:

reset in class java.io.Reader

Throws:

java.io.IOException

skip

public long skip(long value)
          throws java.io.IOException

Skips a specified number of characters.

Overrides:

skip in class java.io.Reader

Throws:

java.io.IOException

ready

public boolean ready()
              throws java.io.IOException

Returns true iff input characters are known to be ready.

Overrides:

ready in class java.io.Reader

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Closes the reader.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in class java.io.Reader

Throws:

java.io.IOException