1/*
2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/impl/cookie/DateUtils.java $
3 * $Revision: 677240 $
4 * $Date: 2008-07-16 04:25:47 -0700 (Wed, 16 Jul 2008) $
5 *
6 * ====================================================================
7 * Licensed to the Apache Software Foundation (ASF) under one
8 * or more contributor license agreements.  See the NOTICE file
9 * distributed with this work for additional information
10 * regarding copyright ownership.  The ASF licenses this file
11 * to you under the Apache License, Version 2.0 (the
12 * "License"); you may not use this file except in compliance
13 * with the License.  You may obtain a copy of the License at
14 *
15 *   http://www.apache.org/licenses/LICENSE-2.0
16 *
17 * Unless required by applicable law or agreed to in writing,
18 * software distributed under the License is distributed on an
19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
20 * KIND, either express or implied.  See the License for the
21 * specific language governing permissions and limitations
22 * under the License.
23 * ====================================================================
24 *
25 * This software consists of voluntary contributions made by many
26 * individuals on behalf of the Apache Software Foundation.  For more
27 * information on the Apache Software Foundation, please see
28 * <http://www.apache.org/>.
29 *
30 */
31
32package org.apache.http.impl.cookie;
33
34import java.lang.ref.SoftReference;
35import java.text.ParseException;
36import java.text.SimpleDateFormat;
37import java.util.Calendar;
38import java.util.Date;
39import java.util.HashMap;
40import java.util.Locale;
41import java.util.Map;
42import java.util.TimeZone;
43
44/**
45 * A utility class for parsing and formatting HTTP dates as used in cookies and
46 * other headers.  This class handles dates as defined by RFC 2616 section
47 * 3.3.1 as well as some other common non-standard formats.
48 *
49 * @author Christopher Brown
50 * @author Michael Becke
51 *
52 * @deprecated Please use {@link java.net.URL#openConnection} instead.
53 *     Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a>
54 *     for further details.
55 */
56@Deprecated
57public final class DateUtils {
58
59    /**
60     * Date format pattern used to parse HTTP date headers in RFC 1123 format.
61     */
62    public static final String PATTERN_RFC1123 = "EEE, dd MMM yyyy HH:mm:ss zzz";
63
64    /**
65     * Date format pattern used to parse HTTP date headers in RFC 1036 format.
66     */
67    public static final String PATTERN_RFC1036 = "EEEE, dd-MMM-yy HH:mm:ss zzz";
68
69    /**
70     * Date format pattern used to parse HTTP date headers in ANSI C
71     * <code>asctime()</code> format.
72     */
73    public static final String PATTERN_ASCTIME = "EEE MMM d HH:mm:ss yyyy";
74
75    private static final String[] DEFAULT_PATTERNS = new String[] {
76    	PATTERN_RFC1036,
77    	PATTERN_RFC1123,
78        PATTERN_ASCTIME
79    };
80
81    private static final Date DEFAULT_TWO_DIGIT_YEAR_START;
82
83    public static final TimeZone GMT = TimeZone.getTimeZone("GMT");
84
85    static {
86        Calendar calendar = Calendar.getInstance();
87        calendar.setTimeZone(GMT);
88        calendar.set(2000, Calendar.JANUARY, 1, 0, 0, 0);
89        calendar.set(Calendar.MILLISECOND, 0);
90        DEFAULT_TWO_DIGIT_YEAR_START = calendar.getTime();
91    }
92
93    /**
94     * Parses a date value.  The formats used for parsing the date value are retrieved from
95     * the default http params.
96     *
97     * @param dateValue the date value to parse
98     *
99     * @return the parsed date
100     *
101     * @throws DateParseException if the value could not be parsed using any of the
102     * supported date formats
103     */
104    public static Date parseDate(String dateValue) throws DateParseException {
105        return parseDate(dateValue, null, null);
106    }
107
108    /**
109     * Parses the date value using the given date formats.
110     *
111     * @param dateValue the date value to parse
112     * @param dateFormats the date formats to use
113     *
114     * @return the parsed date
115     *
116     * @throws DateParseException if none of the dataFormats could parse the dateValue
117     */
118    public static Date parseDate(final String dateValue, String[] dateFormats)
119        throws DateParseException {
120        return parseDate(dateValue, dateFormats, null);
121    }
122
123    /**
124     * Parses the date value using the given date formats.
125     *
126     * @param dateValue the date value to parse
127     * @param dateFormats the date formats to use
128     * @param startDate During parsing, two digit years will be placed in the range
129     * <code>startDate</code> to <code>startDate + 100 years</code>. This value may
130     * be <code>null</code>. When <code>null</code> is given as a parameter, year
131     * <code>2000</code> will be used.
132     *
133     * @return the parsed date
134     *
135     * @throws DateParseException if none of the dataFormats could parse the dateValue
136     */
137    public static Date parseDate(
138        String dateValue,
139        String[] dateFormats,
140        Date startDate
141    ) throws DateParseException {
142
143        if (dateValue == null) {
144            throw new IllegalArgumentException("dateValue is null");
145        }
146        if (dateFormats == null) {
147            dateFormats = DEFAULT_PATTERNS;
148        }
149        if (startDate == null) {
150            startDate = DEFAULT_TWO_DIGIT_YEAR_START;
151        }
152        // trim single quotes around date if present
153        // see issue #5279
154        if (dateValue.length() > 1
155            && dateValue.startsWith("'")
156            && dateValue.endsWith("'")
157        ) {
158            dateValue = dateValue.substring (1, dateValue.length() - 1);
159        }
160
161        for (String dateFormat : dateFormats) {
162            SimpleDateFormat dateParser = DateFormatHolder.formatFor(dateFormat);
163            dateParser.set2DigitYearStart(startDate);
164
165            try {
166                return dateParser.parse(dateValue);
167            } catch (ParseException pe) {
168                // ignore this exception, we will try the next format
169            }
170        }
171
172        // we were unable to parse the date
173        throw new DateParseException("Unable to parse the date " + dateValue);
174    }
175
176    /**
177     * Formats the given date according to the RFC 1123 pattern.
178     *
179     * @param date The date to format.
180     * @return An RFC 1123 formatted date string.
181     *
182     * @see #PATTERN_RFC1123
183     */
184    public static String formatDate(Date date) {
185        return formatDate(date, PATTERN_RFC1123);
186    }
187
188    /**
189     * Formats the given date according to the specified pattern.  The pattern
190     * must conform to that used by the {@link SimpleDateFormat simple date
191     * format} class.
192     *
193     * @param date The date to format.
194     * @param pattern The pattern to use for formatting the date.
195     * @return A formatted date string.
196     *
197     * @throws IllegalArgumentException If the given date pattern is invalid.
198     *
199     * @see SimpleDateFormat
200     */
201    public static String formatDate(Date date, String pattern) {
202        if (date == null) throw new IllegalArgumentException("date is null");
203        if (pattern == null) throw new IllegalArgumentException("pattern is null");
204
205        SimpleDateFormat formatter = DateFormatHolder.formatFor(pattern);
206        return formatter.format(date);
207    }
208
209    /** This class should not be instantiated. */
210    private DateUtils() {
211    }
212
213    /**
214     * A factory for {@link SimpleDateFormat}s. The instances are stored in a
215     * threadlocal way because SimpleDateFormat is not threadsafe as noted in
216     * {@link SimpleDateFormat its javadoc}.
217     *
218     * @author Daniel Mueller
219     */
220    final static class DateFormatHolder {
221
222        private static final ThreadLocal<SoftReference<Map<String, SimpleDateFormat>>>
223            THREADLOCAL_FORMATS = new ThreadLocal<SoftReference<Map<String, SimpleDateFormat>>>() {
224
225            @Override
226            protected SoftReference<Map<String, SimpleDateFormat>> initialValue() {
227                return new SoftReference<Map<String, SimpleDateFormat>>(
228                        new HashMap<String, SimpleDateFormat>());
229            }
230
231        };
232
233        /**
234         * creates a {@link SimpleDateFormat} for the requested format string.
235         *
236         * @param pattern
237         *            a non-<code>null</code> format String according to
238         *            {@link SimpleDateFormat}. The format is not checked against
239         *            <code>null</code> since all paths go through
240         *            {@link DateUtils}.
241         * @return the requested format. This simple dateformat should not be used
242         *         to {@link SimpleDateFormat#applyPattern(String) apply} to a
243         *         different pattern.
244         */
245        public static SimpleDateFormat formatFor(String pattern) {
246            SoftReference<Map<String, SimpleDateFormat>> ref = THREADLOCAL_FORMATS.get();
247            Map<String, SimpleDateFormat> formats = ref.get();
248            if (formats == null) {
249                formats = new HashMap<String, SimpleDateFormat>();
250                THREADLOCAL_FORMATS.set(
251                        new SoftReference<Map<String, SimpleDateFormat>>(formats));
252            }
253
254            SimpleDateFormat format = formats.get(pattern);
255            if (format == null) {
256                format = new SimpleDateFormat(pattern, Locale.US);
257                format.setTimeZone(TimeZone.getTimeZone("GMT"));
258                formats.put(pattern, format);
259            }
260
261            return format;
262        }
263
264    }
265
266}
267