1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.mina.http;
21
22 import java.text.DateFormat;
23 import java.text.ParseException;
24 import java.text.SimpleDateFormat;
25 import java.util.Calendar;
26 import java.util.Date;
27 import java.util.Locale;
28 import java.util.TimeZone;
29 import java.util.regex.Pattern;
30
31 public class DateUtil {
32
33 private final static Locale LOCALE = Locale.US;
34 private final static TimeZone GMT_ZONE;
35 private final static String RFC_1123_PATTERN = "EEE, dd MMM yyyy HH:mm:ss zzz";
36 private final static DateFormat RFC_1123_FORMAT;
37
38 /** Pattern to find digits only. */
39 private final static Pattern DIGIT_PATTERN = Pattern.compile("^\\d+$");
40
41 static {
42 RFC_1123_FORMAT = new SimpleDateFormat(DateUtil.RFC_1123_PATTERN, DateUtil.LOCALE);
43 GMT_ZONE = TimeZone.getTimeZone("GMT");
44 DateUtil.RFC_1123_FORMAT.setTimeZone(DateUtil.GMT_ZONE);
45 }
46
47 public static String getCurrentAsString() {
48 synchronized(DateUtil.RFC_1123_FORMAT) {
49 return DateUtil.RFC_1123_FORMAT.format(new Date()); //NOPMD
50 }
51 }
52
53 /**
54 * Translate a given date <code>String</code> in the <em>RFC 1123</em>
55 * format to a <code>long</code> representing the number of milliseconds
56 * since epoch.
57 *
58 * @param dateString a date <code>String</code> in the <em>RFC 1123</em>
59 * format.
60 * @return the parsed <code>Date</code> in milliseconds.
61 */
62 private static long parseDateStringToMilliseconds(final String dateString) {
63
64 try {
65 synchronized (DateUtil.RFC_1123_FORMAT) {
66 return DateUtil.RFC_1123_FORMAT.parse(dateString).getTime(); //NOPMD
67 }
68 } catch (final ParseException e) {
69 return 0;
70 }
71 }
72
73 /**
74 * Parse a given date <code>String</code> to a <code>long</code>
75 * representation of the time. Where the provided value is all digits the
76 * value is returned as a <code>long</code>, otherwise attempt is made to
77 * parse the <code>String</code> as a <em>RFC 1123</em> date.
78 *
79 * @param dateValue the value to parse.
80 * @return the <code>long</code> value following parse, or zero where not
81 * successful.
82 */
83 public static long parseToMilliseconds(final String dateValue) {
84
85 long ms = 0;
86
87 if (DateUtil.DIGIT_PATTERN.matcher(dateValue).matches()) {
88 ms = Long.parseLong(dateValue);
89 } else {
90 ms = parseDateStringToMilliseconds(dateValue);
91 }
92
93 return ms;
94 }
95
96 /**
97 * Converts a millisecond representation of a date to a
98 * <code>RFC 1123</code> formatted <code>String</code>.
99 *
100 * @param dateValue the <code>Date</code> represented as milliseconds.
101 * @return a <code>String</code> representation of the date.
102 */
103 public static String parseToRFC1123(final long dateValue) {
104
105 final Calendar calendar = Calendar.getInstance();
106 calendar.setTimeInMillis(dateValue);
107
108 synchronized (DateUtil.RFC_1123_FORMAT) {
109 return DateUtil.RFC_1123_FORMAT.format(calendar.getTime()); //NOPMD
110 }
111 }
112
113 /**
114 * Convert a given <code>Date</code> object to a <code>RFC 1123</code>
115 * formatted <code>String</code>.
116 *
117 * @param date the <code>Date</code> object to convert
118 * @return a <code>String</code> representation of the date.
119 */
120 public static String getDateAsString(Date date) {
121 synchronized (DateUtil.RFC_1123_FORMAT) {
122 return RFC_1123_FORMAT.format(date); //NOPMD
123 }
124 }
125
126 }