edu.northwestern.at.utils

Class UnicodeReader

java.lang.Object

java.io.Reader

edu.northwestern.at.utils.UnicodeReader

All Implemented Interfaces:

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

public class UnicodeReader
extends java.io.Reader

Generic unicode text reader.

Uses BOM mark to identify the encoding to be used. When BOM is not found, uses given default or system encoding.

Original pseudocode : Thomas Weidenfeller
Implementation tweaked: Aki Nieminen

http://www.unicode.org/unicode/faq/utf_bom.html
BOMs:
00 00 FE FF = UTF-32, big-endian
FF FE 00 00 = UTF-32, little-endian
EF BB BF = UTF-8,
FE FF = UTF-16, big-endian
FF FE = UTF-16, little-endian

Field Summary

Fields

Modifier and Type	Field and Description
(package private) java.lang.String	defaultEnc
(package private) java.io.PushbackInputStream	internalIn
(package private) java.io.InputStreamReader	internalIn2

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor and Description
UnicodeReader(java.io.InputStream in) Create Unicode reader.
UnicodeReader(java.io.InputStream in, java.lang.String defaultEnc) Create Unicode reader.

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
java.lang.String	getDefaultEncoding()
java.lang.String	getEncoding() Get stream encoding or NULL if stream is uninitialized.
protected void	init() Read-ahead four bytes and check for BOM marks.
int	read(char[] cbuf, int off, int len)

Methods inherited from class java.io.Reader

mark, markSupported, read, read, read, ready, reset, skip

Methods inherited from class java.lang.Object

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

Field Detail

internalIn2

java.io.InputStreamReader internalIn2

defaultEnc

java.lang.String defaultEnc

internalIn

java.io.PushbackInputStream internalIn

Constructor Detail

UnicodeReader

public UnicodeReader(java.io.InputStream in)

Create Unicode reader.

Parameters:

in - inputstream to be read

UnicodeReader

public UnicodeReader(java.io.InputStream in,
             java.lang.String defaultEnc)

Create Unicode reader.

Parameters:

in - inputstream to be read

defaultEnc - default encoding if stream does not have BOM marker. Give NULL to use system-level default.

Method Detail

getDefaultEncoding

public java.lang.String getDefaultEncoding()

getEncoding

public java.lang.String getEncoding()

Get stream encoding or NULL if stream is uninitialized. Call init() or read() method to initialize it.

init

protected void init()
             throws java.io.IOException

Read-ahead four bytes and check for BOM marks. Extra bytes are unread back to the stream, only BOM bytes are skipped.

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

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

read

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

Specified by:

read in class java.io.Reader

Throws:

java.io.IOException