TimeUtils.java revision 9066cfe9886ac131c34d59ed0e2d287b0e3c0087
19066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project/* 29066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Copyright (C) 2006 The Android Open Source Project 39066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 49066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Licensed under the Apache License, Version 2.0 (the "License"); 59066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * you may not use this file except in compliance with the License. 69066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * You may obtain a copy of the License at 79066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 89066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 99066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 109066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Unless required by applicable law or agreed to in writing, software 119066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 129066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 139066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * See the License for the specific language governing permissions and 149066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * limitations under the License. 159066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 169066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 179066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectpackage android.util; 189066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 199066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport android.content.res.Resources; 209066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport android.content.res.XmlResourceParser; 219066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 229066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport org.apache.harmony.luni.internal.util.ZoneInfoDB; 239066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport org.xmlpull.v1.XmlPullParser; 249066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport org.xmlpull.v1.XmlPullParserException; 259066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 269066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport java.io.IOException; 279066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport java.util.TimeZone; 289066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport java.util.Date; 299066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 309066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport com.android.internal.util.XmlUtils; 319066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 329066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project/** 339066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * A class containing utility methods related to time zones. 349066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 359066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectpublic class TimeUtils { 369066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project private static final String TAG = "TimeUtils"; 379066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 389066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 399066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Tries to return a time zone that would have had the specified offset 409066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * and DST value at the specified moment in the specified country. 419066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Returns null if no suitable zone could be found. 429066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 439066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static TimeZone getTimeZone(int offset, boolean dst, long when, String country) { 449066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (country == null) { 459066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return null; 469066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 479066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 489066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project TimeZone best = null; 499066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 509066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project Resources r = Resources.getSystem(); 519066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project XmlResourceParser parser = r.getXml(com.android.internal.R.xml.time_zones_by_country); 529066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project Date d = new Date(when); 539066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 549066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project TimeZone current = TimeZone.getDefault(); 559066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project String currentName = current.getID(); 569066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project int currentOffset = current.getOffset(when); 579066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project boolean currentDst = current.inDaylightTime(d); 589066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 599066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project try { 609066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project XmlUtils.beginDocument(parser, "timezones"); 619066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 629066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project while (true) { 639066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project XmlUtils.nextElement(parser); 649066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 659066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project String element = parser.getName(); 669066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (element == null || !(element.equals("timezone"))) { 679066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project break; 689066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 699066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 709066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project String code = parser.getAttributeValue(null, "code"); 719066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 729066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (country.equals(code)) { 739066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (parser.next() == XmlPullParser.TEXT) { 749066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project String maybe = parser.getText(); 759066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 769066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // If the current time zone is from the right country 779066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // and meets the other known properties, keep it 789066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // instead of changing to another one. 799066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 809066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (maybe.equals(currentName)) { 819066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (currentOffset == offset && currentDst == dst) { 829066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return current; 839066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 849066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 859066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 869066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // Otherwise, take the first zone from the right 879066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // country that has the correct current offset and DST. 889066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // (Keep iterating instead of returning in case we 899066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // haven't encountered the current time zone yet.) 909066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 919066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (best == null) { 929066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project TimeZone tz = TimeZone.getTimeZone(maybe); 939066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 949066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (tz.getOffset(when) == offset && 959066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project tz.inDaylightTime(d) == dst) { 969066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project best = tz; 979066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 989066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 999066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1009066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1019066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1029066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } catch (XmlPullParserException e) { 1039066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project Log.e(TAG, "Got exception while getting preferred time zone.", e); 1049066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } catch (IOException e) { 1059066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project Log.e(TAG, "Got exception while getting preferred time zone.", e); 1069066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } finally { 1079066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project parser.close(); 1089066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1099066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 1109066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return best; 1119066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1129066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 1139066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 1149066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Returns a String indicating the version of the time zone database currently 1159066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * in use. The format of the string is dependent on the underlying time zone 1169066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * database implementation, but will typically contain the year in which the database 1179066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * was updated plus a letter from a to z indicating changes made within that year. 1189066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 1199066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <p>Time zone database updates should be expected to occur periodically due to 1209066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * political and legal changes that cannot be anticipated in advance. Therefore, 1219066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * when computing the UTC time for a future event, applications should be aware that 1229066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * the results may differ following a time zone database update. This method allows 1239066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * applications to detect that a database change has occurred, and to recalculate any 1249066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * cached times accordingly. 1259066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 1269066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <p>The time zone database may be assumed to change only when the device runtime 1279066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * is restarted. Therefore, it is not necessary to re-query the database version 1289066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * during the lifetime of an activity. 1299066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 1309066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static String getTimeZoneDatabaseVersion() { 1319066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return ZoneInfoDB.getVersion(); 1329066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1339066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project} 134