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 javax.mail.internet;
021    
022    import java.io.IOException;
023    import java.io.InputStream;
024    import java.io.OutputStream;
025    import java.net.UnknownServiceException;
026    import javax.activation.DataSource;
027    import javax.mail.MessageAware;
028    import javax.mail.MessageContext;
029    import javax.mail.MessagingException;
030    
031    /**
032     * @version $Rev: 702432 $ $Date: 2008-10-07 07:18:08 -0400 (Tue, 07 Oct 2008) $
033     */
034    public class MimePartDataSource implements DataSource, MessageAware {
035        // the part that provides the data form this data source.
036        protected MimePart part;
037    
038        public MimePartDataSource(MimePart part) {
039            this.part = part;
040        }
041    
042        public InputStream getInputStream() throws IOException {
043            try {
044                InputStream stream;
045                if (part instanceof MimeMessage) {
046                    stream = ((MimeMessage) part).getContentStream();
047                } else if (part instanceof MimeBodyPart) {
048                    stream = ((MimeBodyPart) part).getContentStream();
049                } else {
050                    throw new MessagingException("Unknown part");
051                }
052                return checkPartEncoding(part, stream);
053            } catch (MessagingException e) {
054                throw (IOException) new IOException(e.getMessage()).initCause(e);
055            }
056        }
057        
058        
059        /**
060         * For a given part, decide it the data stream requires
061         * wrappering with a stream for decoding a particular 
062         * encoding. 
063         * 
064         * @param part   The part we're extracting.
065         * @param stream The raw input stream for the part.
066         * 
067         * @return An input stream configured for reading the 
068         *         source part and decoding it into raw bytes.
069         */
070        private InputStream checkPartEncoding(MimePart part, InputStream stream) throws MessagingException {
071            String encoding = part.getEncoding();
072            // if nothing is specified, there's nothing to do 
073            if (encoding == null) {
074                return stream; 
075            }
076            // now screen out the ones that never need decoding 
077            encoding = encoding.toLowerCase(); 
078            if (encoding.equals("7bit") || encoding.equals("8bit") || encoding.equals("binary")) {
079                return stream; 
080            }
081            // now we need to check the content type to prevent 
082            // MultiPart types from getting decoded, since the part is just an envelope around other 
083            // parts 
084            String contentType = part.getContentType(); 
085            if (contentType != null) {
086                try {
087                    ContentType type = new ContentType(contentType); 
088                    // no decoding done here 
089                    if (type.match("multipart/*")) {
090                        return stream; 
091                    }
092                } catch (ParseException e) {
093                    // ignored....bad content type means we handle as a normal part 
094                }
095            }
096            // ok, wrap this is a decoding stream if required 
097            return MimeUtility.decode(stream, encoding);
098        }
099        
100    
101        public OutputStream getOutputStream() throws IOException {
102            throw new UnknownServiceException();
103        }
104    
105        public String getContentType() {
106            try {
107                return part.getContentType();
108            } catch (MessagingException e) {
109                return null;
110            }
111        }
112    
113        public String getName() {
114            return "";
115        }
116    
117        public synchronized MessageContext getMessageContext() {
118            return new MessageContext(part);
119        }
120    }