001 package biweekly.util;
002
003 import java.util.regex.Matcher;
004 import java.util.regex.Pattern;
005
006 /*
007 Copyright (c) 2013, Michael Angstadt
008 All rights reserved.
009
010 Redistribution and use in source and binary forms, with or without
011 modification, are permitted provided that the following conditions are met:
012
013 1. Redistributions of source code must retain the above copyright notice, this
014 list of conditions and the following disclaimer.
015 2. Redistributions in binary form must reproduce the above copyright notice,
016 this list of conditions and the following disclaimer in the documentation
017 and/or other materials provided with the distribution.
018
019 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
026 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030
031 /**
032 * Represents a UTC offset.
033 * @author Michael Angstadt
034 */
035 public final class UtcOffset {
036 private final int hour;
037 private final int minute;
038
039 /**
040 * Creates a new UTC offset.
041 * @param hour the hour component (may be negative)
042 * @param minute the minute component (must be between 0 and 59)
043 */
044 public UtcOffset(int hour, int minute) {
045 this.hour = hour;
046 this.minute = minute;
047 }
048
049 /**
050 * Parses a UTC offset from a string.
051 * @param text the text to parse (e.g. "-0500")
052 * @return the parsed UTC offset
053 * @throws IllegalArgumentException if the text cannot be parsed
054 */
055 public static UtcOffset parse(String text) {
056 Pattern timeZoneRegex = Pattern.compile("^([-\\+])?(\\d{1,2})(:?(\\d{2}))?$");
057 Matcher m = timeZoneRegex.matcher(text);
058
059 if (!m.find()) {
060 throw new IllegalArgumentException("Offset string is not in ISO8610 format: " + text);
061 }
062
063 String sign = m.group(1);
064 boolean positive;
065 if ("-".equals(sign)) {
066 positive = false;
067 } else {
068 positive = true;
069 }
070
071 String hourStr = m.group(2);
072 int hourOffset = Integer.parseInt(hourStr);
073 if (!positive) {
074 hourOffset *= -1;
075 }
076
077 String minuteStr = m.group(4);
078 int minuteOffset = (minuteStr == null) ? 0 : Integer.parseInt(minuteStr);
079
080 return new UtcOffset(hourOffset, minuteOffset);
081 }
082
083 /**
084 * Gets the hour component.
085 * @return the hour component
086 */
087 public int getHour() {
088 return hour;
089 }
090
091 /**
092 * Gets the minute component.
093 * @return the minute component
094 */
095 public int getMinute() {
096 return minute;
097 }
098
099 /**
100 * Converts this offset to its ISO string representation using "basic"
101 * format.
102 * @return the ISO string representation (e.g. "-0500")
103 */
104 @Override
105 public String toString() {
106 return toString(false);
107 }
108
109 /**
110 * Converts this offset to its ISO string representation.
111 * @param extended true to use extended format (e.g. "-05:00"), false to use
112 * basic format (e.g. "-0500")
113 * @return the ISO string representation
114 */
115 public String toString(boolean extended) {
116 StringBuilder sb = new StringBuilder();
117
118 boolean positive = hour >= 0;
119 sb.append(positive ? '+' : '-');
120
121 int hour = Math.abs(this.hour);
122 if (hour < 10) {
123 sb.append('0');
124 }
125 sb.append(hour);
126
127 if (extended) {
128 sb.append(':');
129 }
130
131 if (minute < 10) {
132 sb.append('0');
133 }
134 sb.append(minute);
135
136 return sb.toString();
137 }
138
139 @Override
140 public int hashCode() {
141 final int prime = 31;
142 int result = 1;
143 result = prime * result + hour;
144 result = prime * result + minute;
145 return result;
146 }
147
148 @Override
149 public boolean equals(Object obj) {
150 if (this == obj)
151 return true;
152 if (obj == null)
153 return false;
154 if (getClass() != obj.getClass())
155 return false;
156 UtcOffset other = (UtcOffset) obj;
157 if (hour != other.hour)
158 return false;
159 if (minute != other.minute)
160 return false;
161 return true;
162 }
163 }