001    /**
002     *
003     * Copyright 2003-2006 The Apache Software Foundation
004     *
005     *  Licensed under the Apache License, Version 2.0 (the "License");
006     *  you may not use this file except in compliance with the License.
007     *  You may obtain a copy of the License at
008     *
009     *     http://www.apache.org/licenses/LICENSE-2.0
010     *
011     *  Unless required by applicable law or agreed to in writing, software
012     *  distributed under the License is distributed on an "AS IS" BASIS,
013     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     *  See the License for the specific language governing permissions and
015     *  limitations under the License.
016     */
017    
018    package javax.mail.internet;
019    
020    import java.io.ByteArrayOutputStream;
021    import java.io.UnsupportedEncodingException;
022    import java.util.ArrayList;// Represents lists in things like
023    import java.util.Collections;
024    import java.util.Enumeration;
025    import java.util.HashMap;
026    import java.util.Iterator;
027    import java.util.List;
028    import java.util.Map;
029    import java.util.StringTokenizer;
030    
031    import org.apache.geronimo.mail.util.ASCIIUtil;
032    import org.apache.geronimo.mail.util.RFC2231Encoder;
033    import org.apache.geronimo.mail.util.SessionUtil;
034    
035    // Content-Type: text/plain;charset=klingon
036    //
037    // The ;charset=klingon is the parameter list, may have more of them with ';'
038    
039    /**
040     * @version $Rev: 421852 $ $Date: 2006-07-14 03:02:19 -0700 (Fri, 14 Jul 2006) $
041     */
042    public class ParameterList {
043        private static final String MIME_ENCODEPARAMETERS = "mail.mime.encodeparameters";
044        private static final String MIME_DECODEPARAMETERS = "mail.mime.decodeparameters";
045        private static final String MIME_DECODEPARAMETERS_STRICT = "mail.mime.decodeparameters.strict";
046    
047        private static final int HEADER_SIZE_LIMIT = 76;
048    
049        private Map _parameters = new HashMap();
050    
051        private boolean encodeParameters = false;
052        private boolean decodeParameters = false;
053        private boolean decodeParametersStrict = false;
054    
055        public ParameterList() {
056            // figure out how parameter handling is to be performed.
057            getInitialProperties();
058        }
059    
060        public ParameterList(String list) throws ParseException {
061            // figure out how parameter handling is to be performed.
062            getInitialProperties();
063            // get a token parser for the type information
064            HeaderTokenizer tokenizer = new HeaderTokenizer(list, HeaderTokenizer.MIME);
065            while (true) {
066                HeaderTokenizer.Token token = tokenizer.next();
067    
068                switch (token.getType()) {
069                    // the EOF token terminates parsing.
070                    case HeaderTokenizer.Token.EOF:
071                        return;
072    
073                    // each new parameter is separated by a semicolon, including the first, which separates
074                    // the parameters from the main part of the header.
075                    case ';':
076                        // the next token needs to be a parameter name
077                        token = tokenizer.next();
078                        // allow a trailing semicolon on the parameters.
079                        if (token.getType() == HeaderTokenizer.Token.EOF) {
080                            return;
081                        }
082    
083                        if (token.getType() != HeaderTokenizer.Token.ATOM) {
084                            throw new ParseException("Invalid parameter name: " + token.getValue());
085                        }
086    
087                        // get the parameter name as a lower case version for better mapping.
088                        String name = token.getValue().toLowerCase();
089    
090                        token = tokenizer.next();
091    
092                        // parameters are name=value, so we must have the "=" here.
093                        if (token.getType() != '=') {
094                            throw new ParseException("Missing '='");
095                        }
096    
097                        // now the value, which may be an atom or a literal
098                        token = tokenizer.next();
099    
100                        if (token.getType() != HeaderTokenizer.Token.ATOM && token.getType() != HeaderTokenizer.Token.QUOTEDSTRING) {
101                            throw new ParseException("Invalid parameter value: " + token.getValue());
102                        }
103    
104                        String value = token.getValue();
105                        String decodedValue = null;
106    
107                        // we might have to do some additional decoding.  A name that ends with "*"
108                        // is marked as being encoded, so if requested, we decode the value.
109                        if (decodeParameters && name.endsWith("*")) {
110                            // the name needs to be pruned of the marker, and we need to decode the value.
111                            name = name.substring(0, name.length() - 1);
112                            // get a new decoder
113                            RFC2231Encoder decoder = new RFC2231Encoder(HeaderTokenizer.MIME);
114    
115                            try {
116                                // decode the value
117                                decodedValue = decoder.decode(value);
118                            } catch (Exception e) {
119                                // if we're doing things strictly, then raise a parsing exception for errors.
120                                // otherwise, leave the value in its current state.
121                                if (decodeParametersStrict) {
122                                    throw new ParseException("Invalid RFC2231 encoded parameter");
123                                }
124                            }
125                            _parameters.put(name, new ParameterValue(name, decodedValue, value));
126                        }
127                        else {
128                            _parameters.put(name, new ParameterValue(name, value));
129                        }
130    
131                        break;
132    
133                    default:
134                        throw new ParseException("Missing ';'");
135    
136                }
137            }
138        }
139    
140        /**
141         * Get the initial parameters that control parsing and values.
142         * These parameters are controlled by System properties.
143         */
144        private void getInitialProperties() {
145            decodeParameters = SessionUtil.getBooleanProperty(MIME_DECODEPARAMETERS, false);
146            decodeParametersStrict = SessionUtil.getBooleanProperty(MIME_DECODEPARAMETERS_STRICT, false);
147            encodeParameters = SessionUtil.getBooleanProperty(MIME_ENCODEPARAMETERS, true);
148        }
149    
150        public int size() {
151            return _parameters.size();
152        }
153    
154        public String get(String name) {
155            ParameterValue value = (ParameterValue)_parameters.get(name.toLowerCase());
156            if (value != null) {
157                return value.value;
158            }
159            return null;
160        }
161    
162        public void set(String name, String value) {
163            name = name.toLowerCase();
164            _parameters.put(name, new ParameterValue(name, value));
165        }
166    
167        public void set(String name, String value, String charset) {
168            name = name.toLowerCase();
169            // only encode if told to and this contains non-ASCII charactes.
170            if (encodeParameters && !ASCIIUtil.isAscii(value)) {
171                ByteArrayOutputStream out = new ByteArrayOutputStream();
172    
173                try {
174                    RFC2231Encoder encoder = new RFC2231Encoder(HeaderTokenizer.MIME);
175    
176                    // extract the bytes using the given character set and encode
177                    byte[] valueBytes = value.getBytes(MimeUtility.javaCharset(charset));
178    
179                    // the string format is charset''data
180                    out.write(charset.getBytes());
181                    out.write('\'');
182                    out.write('\'');
183                    encoder.encode(valueBytes, 0, valueBytes.length, out);
184    
185                    // default in case there is an exception
186                    _parameters.put(name, new ParameterValue(name, value, new String(out.toByteArray())));
187                    return;
188    
189                } catch (Exception e) {
190                    // just fall through and set the value directly if there is an error
191                }
192            }
193            // default in case there is an exception
194            _parameters.put(name, new ParameterValue(name, value));
195        }
196    
197        public void remove(String name) {
198            _parameters.remove(name);
199        }
200    
201        public Enumeration getNames() {
202            return Collections.enumeration(_parameters.keySet());
203        }
204    
205        public String toString() {
206            // we need to perform folding, but out starting point is 0.
207            return toString(0);
208        }
209    
210        public String toString(int used) {
211            StringBuffer stringValue = new StringBuffer();
212    
213            Iterator values = _parameters.values().iterator();
214    
215            while (values.hasNext()) {
216                ParameterValue parm = (ParameterValue)values.next();
217                // get the values we're going to encode in here.
218                String name = parm.getEncodedName();
219                String value = parm.toString();
220    
221                // add the semicolon separator.  We also add a blank so that folding/unfolding rules can be used.
222                stringValue.append("; ");
223                used += 2;
224    
225                // too big for the current header line?
226                if ((used + name.length() + value.length() + 1) > HEADER_SIZE_LIMIT) {
227                    // and a CRLF-whitespace combo.
228                    stringValue.append("\r\n ");
229                    // reset the counter for a fresh line
230                    used = 3;
231                }
232                // now add the keyword/value pair.
233                stringValue.append(name);
234                stringValue.append("=");
235    
236                used += name.length() + 1;
237    
238                // we're not out of the woods yet.  It is possible that the keyword/value pair by itself might
239                // be too long for a single line.  If that's the case, the we need to fold the value, if possible
240                if (used + value.length() > HEADER_SIZE_LIMIT) {
241                    String foldedValue = MimeUtility.fold(used, value);
242    
243                    stringValue.append(foldedValue);
244    
245                    // now we need to sort out how much of the current line is in use.
246                    int lastLineBreak = foldedValue.lastIndexOf('\n');
247    
248                    if (lastLineBreak != -1) {
249                        used = foldedValue.length() - lastLineBreak + 1;
250                    }
251                    else {
252                        used += foldedValue.length();
253                    }
254                }
255                else {
256                    // no folding required, just append.
257                    stringValue.append(value);
258                    used += value.length();
259                }
260            }
261    
262            return stringValue.toString();
263        }
264    
265    
266        /**
267         * Utility class for representing parameter values in the list.
268         */
269        class ParameterValue {
270            public String name;              // the name of the parameter
271            public String value;             // the original set value
272            public String encodedValue;      // an encoded value, if encoding is requested.
273    
274            public ParameterValue(String name, String value) {
275                this.name = name;
276                this.value = value;
277                this.encodedValue = null;
278            }
279    
280            public ParameterValue(String name, String value, String encodedValue) {
281                this.name = name;
282                this.value = value;
283                this.encodedValue = encodedValue;
284            }
285    
286            public String toString() {
287                if (encodedValue != null) {
288                    return MimeUtility.quote(encodedValue, HeaderTokenizer.MIME);
289                }
290                return MimeUtility.quote(value, HeaderTokenizer.MIME);
291            }
292    
293            public String getEncodedName() {
294                if (encodedValue != null) {
295                    return name + "*";
296                }
297                return name;
298            }
299        }
300    }