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 /**
32 * An utility class for Dates manipulations
33 *
34 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
35 */
36 public class DateUtil {
37 private static final Locale LOCALE = Locale.US;
38 private static final TimeZone GMT_ZONE;
39 private static final String RFC_1123_PATTERN = "EEE, dd MMM yyyy HH:mm:ss zzz";
40 private static final DateFormat RFC_1123_FORMAT;
41
42 /** Pattern to find digits only. */
43 private static final Pattern DIGIT_PATTERN = Pattern.compile("^\\d+$");
44
45 static {
46 RFC_1123_FORMAT = new SimpleDateFormat(DateUtil.RFC_1123_PATTERN, DateUtil.LOCALE);
47 GMT_ZONE = TimeZone.getTimeZone("GMT");
48 DateUtil.RFC_1123_FORMAT.setTimeZone(DateUtil.GMT_ZONE);
49 }
50
51 private DateUtil() {
52 }
53
54 /**
55 * @return The current date as a string
56 */
57 public static String getCurrentAsString() {
58 synchronized(DateUtil.RFC_1123_FORMAT) {
59 return DateUtil.RFC_1123_FORMAT.format(new Date()); //NOPMD
60 }
61 }
62
63 /**
64 * Translate a given date <code>String</code> in the <em>RFC 1123</em>
65 * format to a <code>long</code> representing the number of milliseconds
66 * since epoch.
67 *
68 * @param dateString a date <code>String</code> in the <em>RFC 1123</em> format.
69 * @return the parsed <code>Date</code> in milliseconds.
70 */
71 private static long parseDateStringToMilliseconds(String dateString) {
72 try {
73 synchronized (DateUtil.RFC_1123_FORMAT) {
74 return DateUtil.RFC_1123_FORMAT.parse(dateString).getTime(); //NOPMD
75 }
76 } catch (ParseException e) {
77 return 0;
78 }
79 }
80
81 /**
82 * Parse a given date <code>String</code> to a <code>long</code>
83 * representation of the time. Where the provided value is all digits the
84 * value is returned as a <code>long</code>, otherwise attempt is made to
85 * parse the <code>String</code> as a <em>RFC 1123</em> date.
86 *
87 * @param dateValue the value to parse.
88 * @return the <code>long</code> value following parse, or zero where not successful.
89 */
90 public static long parseToMilliseconds(String dateValue) {
91 if (DateUtil.DIGIT_PATTERN.matcher(dateValue).matches()) {
92 return Long.parseLong(dateValue);
93 } else {
94 return parseDateStringToMilliseconds(dateValue);
95 }
96 }
97
98 /**
99 * Converts a millisecond representation of a date to a
100 * <code>RFC 1123</code> formatted <code>String</code>.
101 *
102 * @param dateValue the <code>Date</code> represented as milliseconds.
103 * @return a <code>String</code> representation of the date.
104 */
105 public static String parseToRFC1123(long dateValue) {
106
107 Calendar calendar = Calendar.getInstance();
108 calendar.setTimeInMillis(dateValue);
109
110 synchronized (DateUtil.RFC_1123_FORMAT) {
111 return DateUtil.RFC_1123_FORMAT.format(calendar.getTime()); //NOPMD
112 }
113 }
114
115 /**
116 * Convert a given <code>Date</code> object to a <code>RFC 1123</code>
117 * formatted <code>String</code>.
118 *
119 * @param date the <code>Date</code> object to convert
120 * @return a <code>String</code> representation of the date.
121 */
122 public static String getDateAsString(Date date) {
123 synchronized (DateUtil.RFC_1123_FORMAT) {
124 return RFC_1123_FORMAT.format(date); //NOPMD
125 }
126 }
127 }