org.apache.jasper.xmlparser
Class UCSReader

java.lang.Object
  java.io.Reader
      org.apache.jasper.xmlparser.UCSReader

All Implemented Interfaces:

java.io.Closeable, java.lang.Readable

public class UCSReader
extends java.io.Reader

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

Author:

Neil Graham, IBM

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).

See Also:

Constant Field Values

UCS2LE

public static final short UCS2LE

See Also:

Constant Field Values

UCS2BE

public static final short UCS2BE

See Also:

Constant Field Values

UCS4LE

public static final short UCS4LE

See Also:

Constant Field Values

UCS4BE

public static final short UCS4BE

See Also:

Constant Field Values

fInputStream

protected java.io.InputStream fInputStream

Input stream.

fBuffer

protected byte[] fBuffer

Byte buffer.

fEncoding

protected short fEncoding

UCSReader

public UCSReader(java.io.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(java.io.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.

read

public int read()
         throws java.io.IOException

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.

Overrides:

read in class java.io.Reader

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:

java.io.IOException - If an I/O error occurs

read

public int read(char[] ch,
                int offset,
                int length)
         throws java.io.IOException

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.

Specified by:

read in class java.io.Reader

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:

java.io.IOException - If an I/O error occurs

skip

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

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

Overrides:

skip in class java.io.Reader

Parameters:

n - The number of characters to skip

Returns:

The number of characters actually skipped

Throws:

java.io.IOException - If an I/O error occurs

ready

public boolean ready()
              throws java.io.IOException

Tell whether this stream is ready to be read.

Overrides:

ready in class java.io.Reader

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:

java.io.IOException - If an I/O error occurs

markSupported

public boolean markSupported()

Tell whether this stream supports the mark() operation.

Overrides:

markSupported in class java.io.Reader

mark

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

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.

Overrides:

mark in class java.io.Reader

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:

java.io.IOException - If the stream does not support mark(), or if some other I/O error occurs

reset

public void reset()
           throws java.io.IOException

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().

Overrides:

reset in class java.io.Reader

Throws:

java.io.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

close

public void close()
           throws java.io.IOException

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.

Specified by:

close in interface java.io.Closeable

Specified by:

close in class java.io.Reader

Throws:

java.io.IOException - If an I/O error occurs