Package org.apache.velocity.io

Class UnicodeInputStream

java.lang.Object

java.io.InputStream

org.apache.velocity.io.UnicodeInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class UnicodeInputStream
extends InputStream

This is an input stream that is unicode BOM aware. This allows you to e.g. read Windows Notepad Unicode files as Velocity templates. It allows you to check the actual encoding of a file by calling getEncodingFromStream() on the input stream reader. This class is not thread safe! When more than one thread wants to use an instance of UnicodeInputStream, the caller must provide synchronization.

Since:

1.5

Version:

$Id$

Author:

Aki Nieminen, Henning P. Schmiedehausen

Field Summary

Fields

Modifier and Type	Field	Description
static org.apache.velocity.io.UnicodeInputStream.UnicodeBOM	UTF16BE_BOM	BOM Marker for UTF 16, big endian.
static org.apache.velocity.io.UnicodeInputStream.UnicodeBOM	UTF16LE_BOM	BOM Marker for UTF 16, little endian.
static org.apache.velocity.io.UnicodeInputStream.UnicodeBOM	UTF32BE_BOM	BOM Marker for UTF 32, big endian.
static org.apache.velocity.io.UnicodeInputStream.UnicodeBOM	UTF32LE_BOM	BOM Marker for UTF 32, little endian.
static org.apache.velocity.io.UnicodeInputStream.UnicodeBOM	UTF8_BOM	BOM Marker for UTF 8.

Constructor Summary

Constructors

Constructor	Description
UnicodeInputStream(InputStream inputStream)	Creates a new UnicodeInputStream object.
UnicodeInputStream(InputStream inputStream, boolean skipBOM)	Creates a new UnicodeInputStream object.

Method Summary

Modifier and Type	Method	Description
int	available()
void	close()
String	getEncodingFromStream()	Read encoding based on BOM.
boolean	isSkipBOM()	Returns true if the input stream discards the BOM.
void	mark(int readlimit)
boolean	markSupported()
int	read()
int	read(byte[] b)
int	read(byte[] b, int off, int len)
protected String	readEncoding()	This method gets the encoding from the stream contents if a BOM exists.
void	reset()
static boolean	sameEncoding(String left, String right)	Helper function to compare encodings
long	skip(long n)

Methods inherited from class java.lang.Object

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

Field Detail

UTF8_BOM

public static final org.apache.velocity.io.UnicodeInputStream.UnicodeBOM UTF8_BOM

BOM Marker for UTF 8. See http://www.unicode.org/unicode/faq/utf_bom.html

UTF16LE_BOM

public static final org.apache.velocity.io.UnicodeInputStream.UnicodeBOM UTF16LE_BOM

BOM Marker for UTF 16, little endian. See http://www.unicode.org/unicode/faq/utf_bom.html

UTF16BE_BOM

public static final org.apache.velocity.io.UnicodeInputStream.UnicodeBOM UTF16BE_BOM

BOM Marker for UTF 16, big endian. See http://www.unicode.org/unicode/faq/utf_bom.html

UTF32LE_BOM

public static final org.apache.velocity.io.UnicodeInputStream.UnicodeBOM UTF32LE_BOM

BOM Marker for UTF 32, little endian. See http://www.unicode.org/unicode/faq/utf_bom.html

UTF32BE_BOM

public static final org.apache.velocity.io.UnicodeInputStream.UnicodeBOM UTF32BE_BOM

BOM Marker for UTF 32, big endian. See http://www.unicode.org/unicode/faq/utf_bom.html

Constructor Detail

UnicodeInputStream

public UnicodeInputStream(InputStream inputStream)
                   throws IllegalStateException,
                          IOException

Creates a new UnicodeInputStream object. Skips a BOM which defines the file encoding.

Parameters:

inputStream - The input stream to use for reading.

Throws:

IllegalStateException

IOException

UnicodeInputStream

public UnicodeInputStream(InputStream inputStream,
                          boolean skipBOM)
                   throws IllegalStateException,
                          IOException

Creates a new UnicodeInputStream object.

Parameters:

inputStream - The input stream to use for reading.

skipBOM - If this is set to true, a BOM read from the stream is discarded. This parameter should normally be true.

Throws:

IllegalStateException

IOException

Method Detail

isSkipBOM

public boolean isSkipBOM()

Returns true if the input stream discards the BOM.

Returns:

True if the input stream discards the BOM.

getEncodingFromStream

public String getEncodingFromStream()

Read encoding based on BOM.

Returns:

The encoding based on the BOM.

Throws:

IllegalStateException - When a problem reading the BOM occured.

readEncoding

protected String readEncoding()
                       throws IOException

This method gets the encoding from the stream contents if a BOM exists. If no BOM exists, the encoding is undefined.

Returns:

The encoding of this streams contents as decided by the BOM or null if no BOM was found.

Throws:

IOException

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

See Also:

InputStream.close()

available

public int available()
              throws IOException

Overrides:

available in class InputStream

Throws:

IOException

See Also:

InputStream.available()

mark

public void mark(int readlimit)

Overrides:

mark in class InputStream

Parameters:

readlimit -

See Also:

InputStream.mark(int)

markSupported

public boolean markSupported()

Overrides:

markSupported in class InputStream

Returns:

mark supported

See Also:

InputStream.markSupported()

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Returns:

read char

Throws:

IOException

See Also:

InputStream.read()

read

public int read(byte[] b)
         throws IOException

Overrides:

read in class InputStream

Parameters:

b - buffer

Returns:

read chars count

Throws:

IOException

See Also:

InputStream.read(byte[])

read

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

Overrides:

read in class InputStream

Parameters:

b - buffer

off - offset

len - length

Returns:

reac char

Throws:

IOException

See Also:

InputStream.read(byte[], int, int)

reset

public void reset()
           throws IOException

Overrides:

reset in class InputStream

Throws:

IOException

See Also:

InputStream.reset()

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class InputStream

Parameters:

n -

Returns:

skipped count

Throws:

IOException

See Also:

InputStream.skip(long)

sameEncoding

public static boolean sameEncoding(String left,
                                   String right)

Helper function to compare encodings

Parameters:

left -

right -

Returns:

true for same encoding