gcc/libjava/gnu/gcj/convert/BytesToUnicode.java

108 lines
3.3 KiB
Java

/* Copyright (C) 1999 Red Hat, Inc.
This file is part of libgcj.
This software is copyrighted work licensed under the terms of the
Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
details. */
package gnu.gcj.convert;
public abstract class BytesToUnicode
{
/** Buffer to read bytes from.
* The characters inbuffer[inpos] ... inbuffer[inlength-1] are available. */
public byte[] inbuffer;
/** Starting index in buffer to read bytes from. */
public int inpos;
/** End of valid bytes in buffer. */
public int inlength;
static Class defaultDecodingClass;
static synchronized void getDefaultDecodingClass()
{
// Test (defaultDecodingClass == null) again in case of race condition.
if (defaultDecodingClass == null)
{
String encoding = System.getProperty("file.encoding");
String className = "gnu.gcj.convert.Input_"+encoding;
try
{
defaultDecodingClass = Class.forName(className);
}
catch (ClassNotFoundException ex)
{
throw new NoClassDefFoundError("missing default encoding "
+ encoding + " (class "
+ className + " not found)");
}
}
}
public abstract String getName();
public static BytesToUnicode getDefaultDecoder()
{
try
{
if (defaultDecodingClass == null)
getDefaultDecodingClass();
return (BytesToUnicode) defaultDecodingClass.newInstance();
}
catch (Throwable ex)
{
return new Input_8859_1();
}
}
/** Get a byte-stream->char-stream converter given an encoding name. */
public static BytesToUnicode getDecoder (String encoding)
throws java.io.UnsupportedEncodingException
{
String className = "gnu.gcj.convert.Input_"+encoding;
Class decodingClass;
try
{
decodingClass = Class.forName(className);
return (BytesToUnicode) decodingClass.newInstance();
}
catch (Throwable ex)
{
throw new java.io.UnsupportedEncodingException(encoding
+ " (" + ex + ')');
}
}
/** Make input bytes available to the conversion.
* @param buffer source of input bytes
* @param pos index of first available byte
* @param length one more than index of last available byte
*/
public final void setInput(byte[] buffer, int pos, int length)
{
inbuffer = buffer;
inpos = pos;
inlength = length;
}
/** Convert bytes to chars.
* Input bytes are taken from this.inbuffer. The available input
* bytes start at inbuffer[inpos], and end at inbuffer[inlength-1].
* @param outbuffer buffer for the converted character
* @param outpos position in buffer to start putting converted characters
* @param count the maximum number of characters to convert
* @return number of chars placed in outbuffer.
* Also, this.inpos is incremented by the number of bytes consumed.
*
* (Note the asymmetry in that the input upper bound is inbuffer[inlength-1],
* while the output upper bound is outbuffer[outpos+count-1]. The
* justification is that inlength is like the count field of a
* BufferedInputStream, while the count parameter is like the
* length parameter of a read request.) The count parameter is
* also defined to be <= outbuffer.length - outpos (per the specification
* of the length parameter for a read request).
*/
public abstract int read (char[] outbuffer, int outpos, int count);
}