001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *  http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    
020    package org.apache.geronimo.mail.util;
021    
022    import java.io.IOException;
023    import java.io.OutputStream;
024    import java.io.FilterOutputStream;
025    
026    /**
027     * An implementation of a FilterOutputStream that encodes the
028     * stream data in Q-P encoding format.  This version does the
029     * encoding "on the fly" rather than encoding a single block of
030     * data.  Since this version is intended for use by the MimeUtilty class,
031     * it also handles line breaks in the encoded data.
032     */
033    public class QuotedPrintableEncoderStream extends FilterOutputStream {
034        // our hex encoder utility class.
035        protected QuotedPrintableEncoder encoder;
036    
037        // our default for line breaks
038        protected static final int DEFAULT_LINEBREAK = 76;
039    
040        // the instance line break value
041        protected int lineBreak;
042    
043        /**
044         * Create a Base64 encoder stream that wraps a specifed stream
045         * using the default line break size.
046         *
047         * @param out    The wrapped output stream.
048         */
049        public QuotedPrintableEncoderStream(OutputStream out) {
050            this(out, DEFAULT_LINEBREAK);
051        }
052    
053    
054        public QuotedPrintableEncoderStream(OutputStream out, int lineBreak) {
055            super(out);
056            // lines are processed only in multiple of 4, so round this down.
057            this.lineBreak = (lineBreak / 4) * 4 ;
058    
059            // create an encoder configured to this amount
060            encoder = new QuotedPrintableEncoder(out, this.lineBreak);
061        }
062    
063    
064        public void write(int ch) throws IOException {
065            // have the encoder do the heavy lifting here.
066            encoder.encode(ch);
067        }
068    
069        public void write(byte [] data) throws IOException {
070            write(data, 0, data.length);
071        }
072    
073        public void write(byte [] data, int offset, int length) throws IOException {
074            // the encoder does the heavy lifting here.
075            encoder.encode(data, offset, length);
076        }
077    
078        public void close() throws IOException {
079            out.close();
080        }
081    
082        public void flush() throws IOException {
083            out.flush();
084        }
085    }
086    
087