jodd.io

Class UnicodeInputStream

java.lang.Object

java.io.InputStream

jodd.io.UnicodeInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class UnicodeInputStream
extends java.io.InputStream

Unicode input stream for detecting UTF encodings and reading BOM characters. Detects following BOMs:

• UTF-8
• UTF-16BE
• UTF-16LE
• UTF-32BE
• UTF-32LE

Field Summary

Fields

Modifier and Type	Field and Description
static byte[]	BOM_UTF16_BE
static byte[]	BOM_UTF16_LE
static byte[]	BOM_UTF32_BE
static byte[]	BOM_UTF32_LE
static byte[]	BOM_UTF8
static int	MAX_BOM_SIZE

Constructor Summary

Constructors

Constructor and Description
UnicodeInputStream(java.io.InputStream in, java.nio.charset.Charset targetEncoding) Creates new unicode stream.

Method Summary

Modifier and Type	Method and Description
void	close() Closes input stream.
int	getBOMSize() Returns BOM size in bytes.
java.nio.charset.Charset	getDetectedEncoding() Returns detected UTF encoding or null if no UTF encoding has been detected (i.e.
protected void	init() Detects and decodes encoding from BOM character.
int	read() Reads byte from the stream.

Methods inherited from class java.io.InputStream

available, mark, markSupported, read, read, reset, skip

Methods inherited from class java.lang.Object

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

Field Detail

MAX_BOM_SIZE

public static final int MAX_BOM_SIZE

See Also:

Constant Field Values

BOM_UTF32_BE

public static final byte[] BOM_UTF32_BE

BOM_UTF32_LE

public static final byte[] BOM_UTF32_LE

BOM_UTF8

public static final byte[] BOM_UTF8

BOM_UTF16_BE

public static final byte[] BOM_UTF16_BE

BOM_UTF16_LE

public static final byte[] BOM_UTF16_LE

Constructor Detail

UnicodeInputStream

public UnicodeInputStream(java.io.InputStream in,
                          java.nio.charset.Charset targetEncoding)

Creates new unicode stream. It works in two modes: detect mode and read mode.

Detect mode is active when target encoding is not specified. In detect mode, it tries to detect encoding from BOM if exist. If BOM doesn't exist, encoding is not detected.

Read mode is active when target encoding is set. Then this stream reads optional BOM for given encoding. If BOM doesn't exist, nothing is skipped.

Method Detail

getDetectedEncoding

public java.nio.charset.Charset getDetectedEncoding()

Returns detected UTF encoding or null if no UTF encoding has been detected (i.e. no BOM). If stream is not read yet, it will be initalized first.

init

protected void init()
             throws java.io.IOException

Detects and decodes encoding from BOM character. Reads ahead four bytes and check for BOM marks. Extra bytes are unread back to the stream, so only BOM bytes are skipped.

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Closes input stream. If stream was not used, encoding will be unavailable.

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

Reads byte from the stream.

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException

getBOMSize

public int getBOMSize()

Returns BOM size in bytes. Returns -1 if BOM not found.