com.novell.io
Class CharEncoder

java.lang.Object
  com.novell.io.CharEncoder

Direct Known Subclasses:

ASCIIEncoder, ISO88591Encoder, ISO8859Encoder, UTF16Encoder, UTF8Encoder

public abstract class CharEncoder

extends Object

A simple character encoder class for use with the class EncodingStreamWriter. This exists because with JDK 1.2, there is no way to intercept unencodable characters

An encoding is implemented by deriving a class from CharEncoder, and calling CharEncoder.registerEncoder() at some point before using the encoder.

This class handles unicode surrogate pairs. Derived classes must also.

This class has been updated to use Java 1.4 and later java.nio.charset.CharSetEncoder for encodings not supported by this package.

Constructor Summary

CharEncoder()

Method Summary

protected static Class	doGetClass(String className) Utility method for derived classes to get their Class object for use with registerEncoder().
abstract int	encodeChar(int c, byte[] buffer, int off) Implementation of character encoding
int	encodeChars(char[] chars, int off, int len, byte[] buffer, int outputIndex) Encode some number of characters into bytes in a buffer.
static CharEncoder	getEncoder(String encoding) Create an encoder based on the specified encoding string.
abstract String	getEncoding() Return the string identifier for this encoding scheme.
protected static void	registerEncoder(String encoding, Class encoderClass) Register a CharEncoder-derived class for use with CharEncoder.getEncoder().
void	reset() Call to reset the encoder before outputting a new stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

CharEncoder

public CharEncoder()

Method Detail

getEncoder

public static CharEncoder getEncoder(String encoding)
                              throws UnsupportedEncodingException

Create an encoder based on the specified encoding string.

Parameters:

encoding - The name of the encoding ("ASCII", "UTF-8", "UTF-16", etc.)

Returns:

A CharEncoder object for the specified encoding

Throws:

UnsupportedEncodingException - If an encoder isn't available for the specified encoding scheme.

encodeChars

public int encodeChars(char[] chars,
                       int off,
                       int len,
                       byte[] buffer,
                       int outputIndex)
                throws CharEncodingException,
                       EncodingBufferFullException

Encode some number of characters into bytes in a buffer. Derived classes may want to override this for better performance.

Parameters:

chars - The array of characters to convert

off - The offset into the array of the first character to convert

len - The number of characters to convert

buffer - The byte array in which to store the encoded bytes

outputIndex - The offset into buffer at which to store the encoded bytes

Returns:

The number of bytes stored in the buffer

Throws:

CharEncodingException - If a character could not be encoded

CharEncoderBufferFull - If the passed buffer is too small

EncodingBufferFullException

reset

public void reset()

Call to reset the encoder before outputting a new stream.

encodeChar

public abstract int encodeChar(int c,
                               byte[] buffer,
                               int off)
                        throws CharEncodingException,
                               EncodingBufferFullException

Implementation of character encoding

Parameters:

c - The 32-bit character value to encode

buffer - The byte buffer in which to placed encoded bytes

off - The offset at which to place bytes into the buffer

Returns:

The number of bytes placed in the buffer

Throws:

CharEncodingException - The character could not be encoded in the implemented encoding scheme.

EncodingBufferFullException - There is not enough room in buffer for all the bytes needed to encode the character.

getEncoding

public abstract String getEncoding()

Return the string identifier for this encoding scheme.

Returns:

The string identifier for this encoding scheme.

registerEncoder

protected static void registerEncoder(String encoding,
                                      Class encoderClass)

Register a CharEncoder-derived class for use with CharEncoder.getEncoder().

Parameters:

encoding - The encoding that the encoder supports ("UTF-8", "ISO-8859-1", etc.)

encoderClass - Class object for the CharEncoder-derived class.

See Also:

doGetClass(java.lang.String)

doGetClass

protected static Class doGetClass(String className)

Utility method for derived classes to get their Class object for use with registerEncoder().

Parameters:

className - The name of the Class to return.

Returns:

The Class object, or null if the class is not found.