org.apache.jasper.xmlparser

Class UCSReader

public class UCSReader extends Reader

Reader for UCS-2 and UCS-4 encodings. (i.e., encodings from ISO-10646-UCS-(2|4)).

Version: $Id: UCSReader.java 467222 2006-10-24 03:17:11Z markt $

Author: Neil Graham, IBM

Field Summary
static intDEFAULT_BUFFER_SIZE
Default byte buffer size (8192, larger than that of ASCIIReader since it's reasonable to surmise that the average UCS-4-encoded file should be 4 times as large as the average ASCII-encoded file).
protected byte[]fBuffer
Byte buffer.
protected shortfEncoding
protected InputStreamfInputStream
Input stream.
static shortUCS2BE
static shortUCS2LE
static shortUCS4BE
static shortUCS4LE
Constructor Summary
UCSReader(InputStream inputStream, short encoding)
Constructs an ASCII reader from the specified input stream using the default buffer size.
UCSReader(InputStream inputStream, int size, short encoding)
Constructs an ASCII reader from the specified input stream and buffer size.
Method Summary
voidclose()
Close the stream.
voidmark(int readAheadLimit)
Mark the present position in the stream.
booleanmarkSupported()
Tell whether this stream supports the mark() operation.
intread()
Read a single character.
intread(char[] ch, int offset, int length)
Read characters into a portion of an array.
booleanready()
Tell whether this stream is ready to be read.
voidreset()
Reset the stream.
longskip(long n)
Skip characters.

Field Detail

DEFAULT_BUFFER_SIZE

public static final int DEFAULT_BUFFER_SIZE
Default byte buffer size (8192, larger than that of ASCIIReader since it's reasonable to surmise that the average UCS-4-encoded file should be 4 times as large as the average ASCII-encoded file).

fBuffer

protected byte[] fBuffer
Byte buffer.

fEncoding

protected short fEncoding

fInputStream

protected InputStream fInputStream
Input stream.

UCS2BE

public static final short UCS2BE

UCS2LE

public static final short UCS2LE

UCS4BE

public static final short UCS4BE

UCS4LE

public static final short UCS4LE

Constructor Detail

UCSReader

public UCSReader(InputStream inputStream, short encoding)
Constructs an ASCII reader from the specified input stream using the default buffer size. The Endian-ness and whether this is UCS-2 or UCS-4 needs also to be known in advance.

Parameters: inputStream The input stream. encoding One of UCS2LE, UCS2BE, UCS4LE or UCS4BE.

UCSReader

public UCSReader(InputStream inputStream, int size, short encoding)
Constructs an ASCII reader from the specified input stream and buffer size. The Endian-ness and whether this is UCS-2 or UCS-4 needs also to be known in advance.

Parameters: inputStream The input stream. size The initial buffer size. encoding One of UCS2LE, UCS2BE, UCS4LE or UCS4BE.

Method Detail

close

public void close()
Close the stream. Once a stream has been closed, further read(), ready(), mark(), or reset() invocations will throw an IOException. Closing a previously-closed stream, however, has no effect.

Throws: IOException If an I/O error occurs

mark

public void mark(int readAheadLimit)
Mark the present position in the stream. Subsequent calls to reset() will attempt to reposition the stream to this point. Not all character-input streams support the mark() operation.

Parameters: readAheadLimit Limit on the number of characters that may be read while still preserving the mark. After reading this many characters, attempting to reset the stream may fail.

Throws: IOException If the stream does not support mark(), or if some other I/O error occurs

markSupported

public boolean markSupported()
Tell whether this stream supports the mark() operation.

read

public int read()
Read a single character. This method will block until a character is available, an I/O error occurs, or the end of the stream is reached.

Subclasses that intend to support efficient single-character input should override this method.

Returns: The character read, as an integer in the range 0 to 127 (0x00-0x7f), or -1 if the end of the stream has been reached

Throws: IOException If an I/O error occurs

read

public int read(char[] ch, int offset, int length)
Read characters into a portion of an array. This method will block until some input is available, an I/O error occurs, or the end of the stream is reached.

Parameters: ch Destination buffer offset Offset at which to start storing characters length Maximum number of characters to read

Returns: The number of characters read, or -1 if the end of the stream has been reached

Throws: IOException If an I/O error occurs

ready

public boolean ready()
Tell whether this stream is ready to be read.

Returns: True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.

Throws: IOException If an I/O error occurs

reset

public void reset()
Reset the stream. If the stream has been marked, then attempt to reposition it at the mark. If the stream has not been marked, then attempt to reset it in some way appropriate to the particular stream, for example by repositioning it to its starting point. Not all character-input streams support the reset() operation, and some support reset() without supporting mark().

Throws: IOException If the stream has not been marked, or if the mark has been invalidated, or if the stream does not support reset(), or if some other I/O error occurs

skip

public long skip(long n)
Skip characters. This method will block until some characters are available, an I/O error occurs, or the end of the stream is reached.

Parameters: n The number of characters to skip

Returns: The number of characters actually skipped

Throws: IOException If an I/O error occurs

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