1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.jempbox.impl;
18
19 import java.io.IOException;
20 import java.text.ParseException;
21 import java.text.SimpleDateFormat;
22 import java.util.Calendar;
23 import java.util.Date;
24 import java.util.GregorianCalendar;
25 import java.util.SimpleTimeZone;
26
27 /**
28 * This class is used to convert dates to strings and back using the PDF
29 * date standards. Date are described in PDFReference1.4 section 3.8.2
30 *
31 * @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a>
32 * @author <a href="mailto:chris@oezbek.net">Christopher Oezbek</a>
33 *
34 * @version $Revision: 1.6 $
35 */
36 public class DateConverter
37 {
38 //The Date format is supposed to be the PDF_DATE_FORMAT, but not all PDF documents
39 //will use that date, so I have added a couple other potential formats
40 //to try if the original one does not work.
41 private static final SimpleDateFormat[] POTENTIAL_FORMATS = new SimpleDateFormat[] {
42 new SimpleDateFormat("EEEE, dd MMM yyyy hh:mm:ss a"),
43 new SimpleDateFormat("EEEE, MMM dd, yyyy hh:mm:ss a"),
44 new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'"),
45 new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssz"),
46 new SimpleDateFormat("MM/dd/yyyy hh:mm:ss"),
47 new SimpleDateFormat("MM/dd/yyyy"),
48 new SimpleDateFormat("EEEE, MMM dd, yyyy"), // Acrobat Distiller 1.0.2 for Macintosh
49 new SimpleDateFormat("EEEE MMM dd, yyyy HH:mm:ss"), // ECMP5
50 new SimpleDateFormat("EEEE MMM dd HH:mm:ss z yyyy"), // GNU Ghostscript 7.0.7
51 new SimpleDateFormat("EEEE, MMM dd, yyyy 'at' hh:mma") // Acrobat Net Distiller 1.0 for Windows
52 };
53
54 private DateConverter()
55 {
56 //utility class should not be constructed.
57 }
58
59 /**
60 * This will convert a string to a calendar.
61 *
62 * @param date The string representation of the calendar.
63 *
64 * @return The calendar that this string represents.
65 *
66 * @throws IOException If the date string is not in the correct format.
67 */
68 public static Calendar toCalendar( String date ) throws IOException
69 {
70 Calendar retval = null;
71 if( date != null && date.trim().length() > 0 )
72 {
73 //these are the default values
74 int year = 0;
75 int month = 1;
76 int day = 1;
77 int hour = 0;
78 int minute = 0;
79 int second = 0;
80 //first string off the prefix if it exists
81 try
82 {
83 SimpleTimeZone zone = null;
84 if( date.startsWith( "D:" ) )
85 {
86 date = date.substring( 2, date.length() );
87 }
88 date = date.replaceAll("[-:T]", "");
89
90 if( date.length() < 4 )
91 {
92 throw new IOException( "Error: Invalid date format '" + date + "'" );
93 }
94 year = Integer.parseInt( date.substring( 0, 4 ) );
95 if( date.length() >= 6 )
96 {
97 month = Integer.parseInt( date.substring( 4, 6 ) );
98 }
99 if( date.length() >= 8 )
100 {
101 day = Integer.parseInt( date.substring( 6, 8 ) );
102 }
103 if( date.length() >= 10 )
104 {
105 hour = Integer.parseInt( date.substring( 8, 10 ) );
106 }
107 if( date.length() >= 12 )
108 {
109 minute = Integer.parseInt( date.substring( 10, 12 ) );
110 }
111 if( date.length() >= 14 )
112 {
113 second = Integer.parseInt( date.substring( 12, 14 ) );
114 }
115 if( date.length() >= 15 )
116 {
117 char sign = date.charAt( 14 );
118 if( sign == 'Z' )
119 {
120 zone = new SimpleTimeZone(0,"Unknown");
121 }
122 else
123 {
124 int hours = 0;
125 int minutes = 0;
126 if( date.length() >= 17 )
127 {
128 if( sign == '+' )
129 {
130 //parseInt cannot handle the + sign
131 hours = Integer.parseInt( date.substring( 15, 17 ) );
132 }
133 else
134 {
135 hours = -Integer.parseInt( date.substring( 14, 16 ) );
136 }
137 }
138 if( sign=='+' )
139 {
140 if( date.length() >= 19 )
141 {
142 minutes = Integer.parseInt( date.substring( 17, 19 ) );
143 }
144 }
145 else
146 {
147 if( date.length() >= 18 )
148 {
149 minutes = Integer.parseInt( date.substring( 16, 18 ) );
150 }
151 }
152 zone = new SimpleTimeZone( hours*60*60*1000 + minutes*60*1000, "Unknown" );
153 }
154 }
155 if( zone == null )
156 {
157 retval = new GregorianCalendar();
158 }
159 else
160 {
161 retval = new GregorianCalendar( zone );
162 }
163 retval.clear();
164 retval.set( year, month-1, day, hour, minute, second );
165 }
166 catch( NumberFormatException e )
167 {
168
169 // remove the arbitrary : in the timezone. SimpleDateFormat
170 // can't handle it
171 if (date.substring(date.length()-3,date.length()-2).equals(":") &&
172 (date.substring(date.length()-6,date.length()-5).equals("+") ||
173 date.substring(date.length()-6,date.length()-5).equals("-")))
174 {
175 //thats a timezone string, remove the :
176 date = date.substring(0,date.length()-3) +
177 date.substring(date.length()-2);
178 }
179 for( int i=0; retval == null && i<POTENTIAL_FORMATS.length; i++ )
180 {
181 try
182 {
183 Date utilDate = POTENTIAL_FORMATS[i].parse( date );
184 retval = new GregorianCalendar();
185 retval.setTime( utilDate );
186 }
187 catch( ParseException pe )
188 {
189 //ignore and move to next potential format
190 }
191 }
192 if( retval == null )
193 {
194 //we didn't find a valid date format so throw an exception
195 throw new IOException( "Error converting date:" + date );
196 }
197 }
198 }
199 return retval;
200 }
201
202 private static final void zeroAppend( StringBuffer out, int number )
203 {
204 if( number < 10 )
205 {
206 out.append( "0" );
207 }
208 out.append( number );
209 }
210
211 /**
212 * Convert the date to iso 8601 string format.
213 *
214 * @param cal The date to convert.
215 * @return The date represented as an ISO 8601 string.
216 */
217 public static String toISO8601( Calendar cal )
218 {
219 StringBuffer retval = new StringBuffer();
220
221 retval.append( cal.get( Calendar.YEAR ) );
222 retval.append( "-" );
223 zeroAppend( retval, cal.get( Calendar.MONTH )+1 );
224 retval.append( "-" );
225 zeroAppend( retval, cal.get( Calendar.DAY_OF_MONTH ) );
226 retval.append( "T" );
227 zeroAppend( retval, cal.get( Calendar.HOUR_OF_DAY ));
228 retval.append( ":" );
229 zeroAppend( retval, cal.get( Calendar.MINUTE ));
230 retval.append( ":" );
231 zeroAppend( retval, cal.get( Calendar.SECOND ));
232
233 int timeZone = cal.get( Calendar.ZONE_OFFSET ) + cal.get(Calendar.DST_OFFSET );
234 if( timeZone < 0 )
235 {
236 retval.append( "-" );
237 }
238 else
239 {
240 retval.append( "+" );
241 }
242 timeZone = Math.abs( timeZone );
243 //milliseconds/1000 = seconds = seconds / 60 = minutes = minutes/60 = hours
244 int hours = timeZone/1000/60/60;
245 int minutes = (timeZone - (hours*1000*60*60))/1000/1000;
246 if( hours < 10 )
247 {
248 retval.append( "0" );
249 }
250 retval.append( Integer.toString( hours ) );
251 retval.append( ":" );
252 if( minutes < 10 )
253 {
254 retval.append( "0" );
255 }
256 retval.append( Integer.toString( minutes ) );
257
258 return retval.toString();
259 }
260 }