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36 package org.columba.ristretto.parser;
37
38 import java.util.Date  ;
39 import java.util.TimeZone ;
40 import java.util.regex.Matcher ;
41 import java.util.regex.Pattern ;
42
43
48 public class DateParser {
49 private static final long[] monthOffset = { 0l, 2678400000l, 5097600000l, 7776000000l, 10368000000l, 13046400000l, 15638400000l, 18316800000l, 20995200000l, 23587200000l, 26265600000l, 28857600000l };
62
63 private static final Pattern stringPattern = Pattern
64 .compile("(\\w{3})\\w*");
65
66 private static final Pattern numberPattern = Pattern
67 .compile("(\\d{1,4})");
68
69 private static final Pattern timePattern = Pattern
70 .compile("(\\d\\d):(\\d\\d)(:(\\d\\d))?");
71
72 private static final Pattern timezonePattern = Pattern
73 .compile("((\\+|-)(\\d\\d)(\\d\\d))|(\\\"?(\\w+)\\\"?)");
74
75 private DateParser() {
76 }
77
78 private static int getMonth(String month) {
79 String loweredMonth = month.toLowerCase();
80 char startChar = loweredMonth.charAt(0);
81
82 switch (startChar) {
83 case 'j': {
84 if (loweredMonth.equals("jan"))
85 return 0;
86 if (loweredMonth.equals("jun"))
87 return 5;
88 if (loweredMonth.equals("jul"))
89 return 6;
90 }
91 case 'f': {
92 if (loweredMonth.equals("feb"))
93 return 1;
94 }
95 case 'm': {
96 if (loweredMonth.equals("mar"))
97 return 2;
98 if (loweredMonth.equals("may"))
99 return 4;
100 }
101 case 'a': {
102 if (loweredMonth.equals("apr"))
103 return 3;
104 if (loweredMonth.equals("aug"))
105 return 7;
106 }
107 case 's': {
108 if (loweredMonth.equals("sep"))
109 return 8;
110 }
111 case 'o': {
112 if (loweredMonth.equals("oct"))
113 return 9;
114 }
115 case 'n': {
116 if (loweredMonth.equals("nov"))
117 return 10;
118 }
119 case 'd': {
120 if (loweredMonth.equals("dec"))
121 return 11;
122 }
123 }
124
125 return -1;
126 }
127
128 private static long getLeapYearCorrection(int day, int month, int year) {
129 int normalizedYear = year - 1972;
130 if (day <= 29 && month < 2)
131 normalizedYear -= 1;
132
133 int leapYears = normalizedYear / 4;
134
135 return 86400000l * leapYears;
136 }
137
138
146 public static Date parse(CharSequence dateString) throws ParserException {
147 String temp = dateString.toString();
148
149 Matcher matcher;
150
151 matcher = stringPattern.matcher(temp);
153 int month = -1;
154 while (month == -1 && matcher.find() ) {
155 month = getMonth(matcher.group(1));
156 temp = temp.substring(0,matcher.start()) + temp.substring(matcher.end());
157
158 matcher = stringPattern.matcher(temp);
159 }
160 if (month == -1)
161 throw new ParserException("Invalid Date: " + dateString);
162
163
164 matcher = timePattern.matcher(temp);
165 if (!matcher.find())
166 throw new ParserException("Invalid Date: " + dateString);
167 temp = temp.substring(0,matcher.start()) + temp.substring(matcher.end());
168
169 int hours = Integer.parseInt(matcher.group(1));
171 int minutes = Integer.parseInt(matcher.group(2));
172 int seconds = 0;
173 if (matcher.group(3) != null) {
174 seconds = Integer.parseInt(matcher.group(4));
175 }
176
177
178 matcher = numberPattern.matcher(temp);
180
181 if (!matcher.find())
182 throw new ParserException("Invalid Date: " + dateString);
183 int day = Integer.parseInt(matcher.group());
184 temp = temp.substring(0,matcher.start()) + temp.substring(matcher.end());
185
186 matcher = numberPattern.matcher(temp);
187 if (!matcher.find())
188 throw new ParserException("Invalid Date: " + dateString);
189 int year = Integer.parseInt(matcher.group());
190 if (year < 99) {
191 if (year < 49)
192 year += 2000;
193 else
194 year += 1900;
195 }
196 temp = temp.substring(0,matcher.start()) + temp.substring(matcher.end());
197
198 long date = seconds * 1000l + minutes * 60000l + hours * 3600000l + day
200 * 86400000l + monthOffset[month] + (year - 1970) * 31536000000l
201 + getLeapYearCorrection(day, month, year);
202
203 matcher = timezonePattern.matcher(temp);
205 long zoneoffset = 0;
206 if (matcher.find()) {
207 if (matcher.group(1) != null) {
208 zoneoffset = Integer.parseInt(matcher.group(4)) * 60000l
209 + Integer.parseInt(matcher.group(3)) * 3600000l;
210 if (matcher.group(2).equals("+")) {
211 zoneoffset = -zoneoffset;
212 }
213 } else if (matcher.group(6) != null) {
214 TimeZone timezone = TimeZone.getTimeZone(matcher.group(6));
215 zoneoffset = timezone.getOffset(date);
216 }
217 }
218 date += zoneoffset;
219
220 return new Date (date);
222 }
223 }
224 |
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