/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 1997-2007 Sun Microsystems, Inc. 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 https://glassfish.dev.java.net/public/CDDL+GPL.html * or glassfish/bootstrap/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 glassfish/bootstrap/legal/LICENSE.txt. * Sun designates this particular file as subject to the "Classpath" exception * as provided by Sun in the GPL Version 2 section of the License file that * accompanied this code.  If applicable, add the following below the License * Header, with the fields enclosed by brackets [] replaced by your own * identifying information: "Portions Copyrighted [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	1.11 07/05/04 */package com.sun.mail.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 <code>int</code> in the range <code>0</code>     * to <code>255</code>. If no byte is available because the end of     * the stream has been reached, the value <code>-1</code> 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 <code>-1</code> 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 <SPACE> or <CR/LF>	}	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 <code>len</code> decoded bytes of data from this input stream     * into an array of bytes. This method blocks until some input is     * available.     * <p>     *     * @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     *             <code>-1</code> 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 <code>available</code> 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 ****/}