UTF8Decoderpublic final class UTF8Decoder extends B2CConverter | Moved from ByteChunk - code to convert from UTF8 bytes to chars.
Not used in the current tomcat3.3 : the performance gain is not very
big if the String is created, only if we avoid that and work only
on char[]. Until than, it's better to be safe. ( I tested this code
with 2 and 3 bytes chars, and it works fine in xerces )
Cut from xerces' UTF8Reader.copyMultiByteCharData() |
| Fields Summary |
|---|
| private static com.sun.org.apache.commons.logging.Log | log | | private static int | debug |
| Constructors Summary |
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public UTF8Decoder()
// may have state !!
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| Methods Summary |
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| public void | convert(ByteChunk mb, CharChunk cb)
int bytesOff=mb.getOffset();
int bytesLen=mb.getLength();
byte bytes[]=mb.getBytes();
int j=bytesOff;
int end=j+bytesLen;
while( j< end ) {
int b0=0xff & bytes[j];
if( (b0 & 0x80) == 0 ) {
cb.append((char)b0);
j++;
continue;
}
// 2 byte ?
if( j++ >= end ) {
// ok, just ignore - we could throw exception
throw new IOException( "Conversion error - EOF " );
}
int b1=0xff & bytes[j];
// ok, let's the fun begin - we're handling UTF8
if ((0xe0 & b0) == 0xc0) { // 110yyyyy 10xxxxxx (0x80 to 0x7ff)
int ch = ((0x1f & b0)<<6) + (0x3f & b1);
if(debug>0)
log("Convert " + b0 + " " + b1 + " " + ch + ((char)ch));
cb.append((char)ch);
j++;
continue;
}
if( j++ >= end )
return ;
int b2=0xff & bytes[j];
if( (b0 & 0xf0 ) == 0xe0 ) {
if ((b0 == 0xED && b1 >= 0xA0) ||
(b0 == 0xEF && b1 == 0xBF && b2 >= 0xBE)) {
if(debug>0)
log("Error " + b0 + " " + b1+ " " + b2 );
throw new IOException( "Conversion error 2");
}
int ch = ((0x0f & b0)<<12) + ((0x3f & b1)<<6) + (0x3f & b2);
cb.append((char)ch);
if(debug>0)
log("Convert " + b0 + " " + b1+ " " + b2 + " " + ch +
((char)ch));
j++;
continue;
}
if( j++ >= end )
return ;
int b3=0xff & bytes[j];
if (( 0xf8 & b0 ) == 0xf0 ) {
if (b0 > 0xF4 || (b0 == 0xF4 && b1 >= 0x90)) {
if(debug>0)
log("Convert " + b0 + " " + b1+ " " + b2 + " " + b3);
throw new IOException( "Conversion error ");
}
int ch = ((0x0f & b0)<<18) + ((0x3f & b1)<<12) +
((0x3f & b2)<<6) + (0x3f & b3);
if(debug>0)
log("Convert " + b0 + " " + b1+ " " + b2 + " " + b3 + " " +
ch + ((char)ch));
if (ch < 0x10000) {
cb.append( (char)ch );
} else {
cb.append((char)(((ch-0x00010000)>>10)+
0xd800));
cb.append((char)(((ch-0x00010000)&0x3ff)+
0xdc00));
}
j++;
continue;
} else {
// XXX Throw conversion exception !!!
if(debug>0)
log("Convert " + b0 + " " + b1+ " " + b2 + " " + b3);
throw new IOException( "Conversion error 4" );
}
}
| | void | log(java.lang.String s)
if (log.isDebugEnabled())
log.debug("UTF8Decoder: " + s );
| | public void | recycle()
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