com.silentgo.servlet.oreilly.multipart.MacBinaryDecoderOutputStream Maven / Gradle / Ivy
// Copyright (C) 1999-2001 by Jason Hunter .
// All rights reserved. Use of this class is limited.
// Please see the LICENSE for more information.
package com.silentgo.servlet.oreilly.multipart;
import java.io.OutputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
/**
* A MacBinaryDecoderOutput filters MacBinary files to normal
* files on the fly; optimized for speed more than readability.
*
* @author Jason Hunter
*/
public class MacBinaryDecoderOutputStream extends FilterOutputStream {
private int bytesFiltered = 0;
private int dataForkLength = 0;
public MacBinaryDecoderOutputStream(OutputStream out) {
super(out);
}
public void write(int b) throws IOException {
// Bytes 83 through 86 are a long representing the data fork length
// Check <= 86 first to short circuit early in the common case
if (bytesFiltered <= 86 && bytesFiltered >= 83) {
int leftShift = (86 - bytesFiltered) * 8;
dataForkLength = dataForkLength | (b & 0xff) << leftShift;
}
// Bytes 128 up to (128 + dataForkLength - 1) are the data fork
else if (bytesFiltered < (128 + dataForkLength) && bytesFiltered >= 128) {
out.write(b);
}
bytesFiltered++;
}
public void write(byte b[]) throws IOException {
write(b, 0, b.length);
}
public void write(byte b[], int off, int len) throws IOException {
// If the write is for content past the end of the data fork, ignore
if (bytesFiltered >= (128 + dataForkLength)) {
bytesFiltered += len;
}
// If the write is entirely within the data fork, write it directly
else if (bytesFiltered >= 128 &&
(bytesFiltered + len) <= (128 + dataForkLength)) {
out.write(b, off, len);
bytesFiltered += len;
}
// Otherwise, do the write a byte at a time to get the logic above
else {
for (int i = 0 ; i < len ; i++) {
write(b[off + i]);
}
}
}
}