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Diffstat (limited to 'libjava/classpath/vm/reference/java/util/VMTimeZone.java')
| -rw-r--r-- | libjava/classpath/vm/reference/java/util/VMTimeZone.java | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/libjava/classpath/vm/reference/java/util/VMTimeZone.java b/libjava/classpath/vm/reference/java/util/VMTimeZone.java new file mode 100644 index 000000000..11061aa32 --- /dev/null +++ b/libjava/classpath/vm/reference/java/util/VMTimeZone.java @@ -0,0 +1,300 @@ +/* java.util.VMTimeZone + Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007 + Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.util; + +import gnu.classpath.Configuration; +import gnu.classpath.SystemProperties; +import gnu.java.util.ZoneInfo; +import java.util.TimeZone; + +import java.io.*; + +/** + * + */ +final class VMTimeZone +{ + static + { + if (Configuration.INIT_LOAD_LIBRARY) + { + System.loadLibrary("javautil"); + } + } + + /** + * This method returns a time zone id string which is in the form + * (standard zone name) or (standard zone name)(GMT offset) or + * (standard zone name)(GMT offset)(daylight time zone name). The + * GMT offset can be in seconds, or where it is evenly divisible by + * 3600, then it can be in hours. The offset must be the time to + * add to the local time to get GMT. If a offset is given and the + * time zone observes daylight saving then the (daylight time zone + * name) must also be given (otherwise it is assumed the time zone + * does not observe any daylight savings). + * <p> + * The result of this method is given to the method + * TimeZone.getDefaultTimeZone(String) which tries to map the time + * zone id to a known TimeZone. See that method on how the returned + * String is mapped to a real TimeZone object. + * <p> + * The reference implementation which is made for GNU/Posix like + * systems calls <code>System.getenv("TZ")</code>, + * <code>readTimeZoneFile("/etc/timezone")</code>, + * <code>ZoneInfo.readTZFile((String)null, "/etc/localtime")</code> + * and finally <code>getSystemTimeZoneId()</code> till a supported + * TimeZone is found through + * <code>TimeZone.getDefaultTimeZone(String)</code>. + * If every method fails <code>null</code> is returned (which means + * the TimeZone code will fall back on GMT as default time zone). + * <p> + * Note that this method is called inside a + * <code>AccessController.doPrivileged()</code> block and runs with + * the priviliges of the java.util system classes. It will only be + * called when the default time zone is not yet set, the system + * property user.timezone isn't set and it is requested for the + * first time. + */ + static TimeZone getDefaultTimeZoneId() + { + TimeZone zone = null; + + // See if TZ environment variable is set and accessible. + String tzid = System.getenv("TZ"); + if (tzid != null && !tzid.equals("")) + zone = TimeZone.getDefaultTimeZone(tzid); + + // Try to parse /etc/timezone. + if (zone == null) + { + tzid = readTimeZoneFile("/etc/timezone"); + if (tzid != null && !tzid.equals("")) + zone = TimeZone.getDefaultTimeZone(tzid); + } + + // Try to parse /etc/localtime + if (zone == null) + { + zone = ZoneInfo.readTZFile((String) null, "/etc/localtime"); + if (zone != null) + { + // Try to find a more suitable ID for the /etc/localtime + // timezone. + // Sometimes /etc/localtime is a symlink to some + // /usr/share/zoneinfo/ file. + String id = null; + try + { + id = new File("/etc/localtime").getCanonicalPath(); + if (id != null) + { + String zoneinfo_dir + = SystemProperties.getProperty("gnu.java.util.zoneinfo.dir"); + if (zoneinfo_dir != null) + zoneinfo_dir + = new File(zoneinfo_dir + + File.separatorChar).getCanonicalPath(); + if (zoneinfo_dir != null && id.startsWith(zoneinfo_dir)) + { + int pos = zoneinfo_dir.length(); + while (pos < id.length() + && id.charAt(pos) == File.separatorChar) + pos++; + if (pos < id.length()) + id = id.substring(pos); + else + id = null; + } + else + id = null; + } + } + catch (IOException ioe) + { + id = null; + } + + if (id == null) + id = readSysconfigClockFile("/etc/sysconfig/clock"); + + if (id != null) + zone.setID(id); + } + } + + // Try some system specific way + if (zone == null) + { + tzid = getSystemTimeZoneId(); + if (tzid != null && !tzid.equals("")) + zone = TimeZone.getDefaultTimeZone(tzid); + } + + return zone; + } + + /** + * Tries to read the time zone name from a file. Only the first + * consecutive letters, digits, slashes, dashes and underscores are + * read from the file. If the file cannot be read or an IOException + * occurs null is returned. + * <p> + * The /etc/timezone file is not standard, but a lot of systems have + * it. If it exist the first line always contains a string + * describing the timezone of the host of domain. Some systems + * contain a /etc/TIMEZONE file which is used to set the TZ + * environment variable (which is checked before /etc/timezone is + * read). + */ + private static String readTimeZoneFile(String file) + { + File f = new File(file); + if (!f.exists()) + return null; + + InputStreamReader isr = null; + try + { + FileInputStream fis = new FileInputStream(f); + BufferedInputStream bis = new BufferedInputStream(fis); + isr = new InputStreamReader(bis); + + StringBuffer sb = new StringBuffer(); + int i = isr.read(); + while (i != -1) + { + char c = (char) i; + if (Character.isLetter(c) || Character.isDigit(c) + || c == '/' || c == '-' || c == '_') + { + sb.append(c); + i = isr.read(); + } + else + break; + } + return sb.toString(); + } + catch (IOException ioe) + { + // Parse error, not a proper tzfile. + return null; + } + finally + { + try + { + if (isr != null) + isr.close(); + } + catch (IOException ioe) + { + // Error while close, nothing we can do. + } + } + } + + /** + * Tries to read the time zone name from a file. + * If the file cannot be read or an IOException occurs null is returned. + * <p> + * The /etc/sysconfig/clock file is not standard, but a lot of systems + * have it. The file is included by shell scripts and the timezone + * name is defined in ZONE variable. + * This routine should grok it with or without quotes: + * ZONE=America/New_York + * or + * ZONE="Europe/London" + */ + private static String readSysconfigClockFile(String file) + { + BufferedReader br = null; + try + { + FileInputStream fis = new FileInputStream(file); + BufferedInputStream bis = new BufferedInputStream(fis); + br = new BufferedReader(new InputStreamReader(bis)); + + for (String line = br.readLine(); line != null; line = br.readLine()) + { + line = line.trim(); + if (line.length() < 8 || !line.startsWith("ZONE=")) + continue; + int posstart = 6; + int posend; + if (line.charAt(5) == '"') + posend = line.indexOf('"', 6); + else if (line.charAt(5) == '\'') + posend = line.indexOf('\'', 6); + else + { + posstart = 5; + posend = line.length(); + } + if (posend < 0) + return null; + return line.substring(posstart, posend); + } + return null; + } + catch (IOException ioe) + { + // Parse error, not a proper tzfile. + return null; + } + finally + { + try + { + if (br != null) + br.close(); + } + catch (IOException ioe) + { + // Error while close, nothing we can do. + } + } + } + + /** + * Tries to get the system time zone id through native code. + */ + private static native String getSystemTimeZoneId(); +} |