com.sun.xml.messaging.saaj.packaging.mime.util.QPDecoderStream Maven / Gradle / Ivy
Show all versions of saaj-impl Show documentation
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 1997-2012 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* http://glassfish.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
/*
* @(#)QPDecoderStream.java 1.9 02/04/02
*/
package com.sun.xml.messaging.saaj.packaging.mime.util;
import java.io.*;
/**
* This class implements a QP Decoder. It is implemented as
* a FilterInputStream, so one can just wrap this class around
* any input stream and read bytes from this filter. The decoding
* is done as the bytes are read out.
*
* @author John Mani
*/
public class QPDecoderStream extends FilterInputStream {
protected byte[] ba = new byte[2];
protected int spaces = 0;
/**
* Create a Quoted Printable decoder that decodes the specified
* input stream.
* @param in the input stream
*/
public QPDecoderStream(InputStream in) {
super(new PushbackInputStream(in, 2)); // pushback of size=2
}
/**
* Read the next decoded byte from this input stream. The byte
* is returned as an int in the range 0
* to 255. If no byte is available because the end of
* the stream has been reached, the value -1 is returned.
* This method blocks until input data is available, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next byte of data, or -1 if the end of the
* stream is reached.
* @exception IOException if an I/O error occurs.
*/
public int read() throws IOException {
if (spaces > 0) {
// We have cached space characters, return one
spaces--;
return ' ';
}
int c = in.read();
if (c == ' ') {
// Got space, keep reading till we get a non-space char
while ((c = in.read()) == ' ')
spaces++;
if (c == '\r' || c == '\n' || c == -1)
// If the non-space char is CR/LF/EOF, the spaces we got
// so far is junk introduced during transport. Junk 'em.
spaces = 0;
else {
// The non-space char is NOT CR/LF, the spaces are valid.
((PushbackInputStream)in).unread(c);
c = ' ';
}
return c; // return either or
}
else if (c == '=') {
// QP Encoded atom. Decode the next two bytes
int a = in.read();
if (a == '\n') {
/* Hmm ... not really confirming QP encoding, but lets
* allow this as a LF terminated encoded line .. and
* consider this a soft linebreak and recurse to fetch
* the next char.
*/
return read();
} else if (a == '\r') {
// Expecting LF. This forms a soft linebreak to be ignored.
int b = in.read();
if (b != '\n')
/* Not really confirming QP encoding, but
* lets allow this as well.
*/
((PushbackInputStream)in).unread(b);
return read();
} else if (a == -1) {
// Not valid QP encoding, but we be nice and tolerant here !
return -1;
} else {
ba[0] = (byte)a;
ba[1] = (byte)in.read();
try {
return ASCIIUtility.parseInt(ba, 0, 2, 16);
} catch (NumberFormatException nex) {
/*
System.err.println(
"Illegal characters in QP encoded stream: " +
ASCIIUtility.toString(ba, 0, 2)
);
*/
((PushbackInputStream)in).unread(ba);
return c;
}
}
}
return c;
}
/**
* Reads up to len decoded bytes of data from this input stream
* into an array of bytes. This method blocks until some input is
* available.
*
*
* @param buf the buffer into which the data is read.
* @param off the start offset of the data.
* @param len the maximum number of bytes read.
* @return the total number of bytes read into the buffer, or
* -1 if there is no more data because the end of
* the stream has been reached.
* @exception IOException if an I/O error occurs.
*/
public int read(byte[] buf, int off, int len) throws IOException {
int i, c;
for (i = 0; i < len; i++) {
if ((c = read()) == -1) {
if (i == 0) // At end of stream, so we should
i = -1; // return -1 , NOT 0.
break;
}
buf[off+i] = (byte)c;
}
return i;
}
/**
* Tests if this input stream supports marks. Currently this class
* does not support marks
*/
public boolean markSupported() {
return false;
}
/**
* Returns the number of bytes that can be read from this input
* stream without blocking. The QP algorithm does not permit
* a priori knowledge of the number of bytes after decoding, so
* this method just invokes the available method
* of the original input stream.
*/
public int available() throws IOException {
// This is bogus ! We don't really know how much
// bytes are available *after* decoding
return in.available();
}
/**** begin TEST program
public static void main(String argv[]) throws Exception {
FileInputStream infile = new FileInputStream(argv[0]);
QPDecoderStream decoder = new QPDecoderStream(infile);
int c;
while ((c = decoder.read()) != -1)
System.out.print((char)c);
System.out.println();
}
*** end TEST program ****/
}