FileDocCategorySizeDatePackage
ZoneInfoDB.javaAPI DocAndroid 1.5 API12876Wed May 06 22:41:04 BST 2009org.apache.harmony.luni.internal.util

ZoneInfoDB

public final class ZoneInfoDB extends Object
A class used to initialize the time zone database. This implementation uses the 'zoneinfo' database as the source of time zone information. However, to conserve disk space the data for all time zones are concatenated into a single file, and a second file is used to indicate the starting position of each time zone record. A third file indicates the version of the zoneinfo databse used to generate the data. {@hide}

Fields Summary
private static final int
TZNAME_LENGTH
private static final int
TZINT_LENGTH
private static final String
ZONE_DIRECTORY_NAME
The directory contining the time zone database files.
private static final String
ZONE_FILE_NAME
The name of the file containing the concatenated time zone records.
private static final String
INDEX_FILE_NAME
The name of the file containing the index to each time zone record within the zoneinfo.dat file.
private static final String
DEFAULT_VERSION
Zoneinfo version used prior to creation of the zoneinfo.version file, equal to "2007h".
private static final String
VERSION_FILE_NAME
The name of the file indicating the database version in use. If the file is not present or is unreadable, we assume a version of DEFAULT_VERSION.
private static Object
lock
private static TimeZone
defaultZone
private static String
version
private static String[]
names
private static int[]
starts
private static int[]
lengths
private static int[]
offsets
Constructors Summary
private ZoneInfoDB()
This class is uninstantiable.


             
      
        // This space intentionally left blank.
Methods Summary
private static java.lang.String[]_getAvailableIDs(int rawOffset, boolean checkOffset)

        List<String> matches = new ArrayList<String>();

        int[] _offsets = ZoneInfoDB.offsets;
        String[] _names = ZoneInfoDB.names;
        int len = _offsets.length;
        for (int i = 0; i < len; i++) {
            if (!checkOffset || _offsets[i] == rawOffset) {
                matches.add(_names[i]);
            }
        }

        return matches.toArray(new String[matches.size()]);
static java.util.TimeZone_getTimeZone(java.lang.String name)

        FileInputStream fis = null;
        int length = 0;

        File f = new File(ZONE_DIRECTORY_NAME + name);
        if (!f.exists()) {
            fis = new FileInputStream(ZONE_FILE_NAME);
            int i = Arrays.binarySearch(ZoneInfoDB.names, name);

            if (i < 0) {
                return null;
            }

            int start = ZoneInfoDB.starts[i];
            length = ZoneInfoDB.lengths[i];

            fis.skip(start);
        }

        if (fis == null) {
            fis = new FileInputStream(f);
            length = (int)f.length(); // data won't exceed 2G!
        }

        byte[] data = new byte[length];
        int nread = 0;
        while (nread < length) {
            int size = fis.read(data, nread, length - nread);
            if (size > 0) {
                nread += size;
            }
        }

        try {
            fis.close();
        } catch (IOException e3) {
            // probably better to continue than to fail here
            java.util.logging.Logger.global.warning("IOException " + e3 +
                " retrieving time zone data");
            e3.printStackTrace();
        }

        if (data.length < 36) {
            return null;
        }
        if (data[0] != 'T" || data[1] != 'Z" ||
            data[2] != 'i" || data[3] != 'f") {
            return null;
        }

        int ntransition = read4(data, 32);
        int ngmtoff = read4(data, 36);
        int base = 44;

        int[] transitions = new int[ntransition];
        for (int i = 0; i < ntransition; i++)
            transitions[i] = read4(data, base + 4 * i);
        base += 4 * ntransition;

        byte[] type = new byte[ntransition];
        for (int i = 0; i < ntransition; i++)
            type[i] = data[base + i];
        base += ntransition;

        int[] gmtoff = new int[ngmtoff];
        byte[] isdst = new byte[ngmtoff];
        byte[] abbrev = new byte[ngmtoff];
        for (int i = 0; i < ngmtoff; i++) {
            gmtoff[i] = read4(data, base + 6 * i);
            isdst[i] = data[base + 6 * i + 4];
            abbrev[i] = data[base + 6 * i + 5];
        }

        base += 6 * ngmtoff;

        return new ZoneInfo(name, transitions, type, gmtoff, isdst, abbrev, data, base);
public static java.lang.String[]getAvailableIDs()

        return _getAvailableIDs(0, false);
public static java.lang.String[]getAvailableIDs(int rawOffset)

        return _getAvailableIDs(rawOffset, true);
public static java.util.TimeZonegetDefault()

        TimeZone zone;

        synchronized (lock) {
            if (defaultZone != null) {
                return defaultZone;
            }

            String zoneName = null;
            TimezoneGetter tzGetter = TimezoneGetter.getInstance();
            if (tzGetter != null) {
                zoneName = tzGetter.getId();
            }
            if (zoneName != null && zoneName.length() > 0) {
                zone = TimeZone.getTimeZone(zoneName.trim());
            } else {
                // use localtime here so that the simulator works
                zone = TimeZone.getTimeZone("localtime");
            }

            defaultZone = zone;
        }
        return zone;
public static java.util.TimeZonegetTimeZone(java.lang.String id)

        if (id != null) {
            if (id.equals("GMT") || id.equals("UTC")) {
                TimeZone tz = new MinimalTimeZone(0);
                tz.setID(id);
                return tz;
            }

            if (id.startsWith("GMT")) {
                return new MinimalTimeZone(parseNumericZone(id) * 1000);
            }
        }

        TimeZone tz = ZoneInfo.getTimeZone(id);

        if (tz != null)
            return tz;

        /*
         * It isn't GMT+anything, and it also isn't something we have
         * in the database.  Give up and return GMT.
         */
        tz = new MinimalTimeZone(0);
        tz.setID("GMT");
        return tz;
public static java.lang.StringgetVersion()

        // Don't attempt to log here because the logger requires this class to be initialized
        try {
            readVersion();
        } catch (IOException e) {
            // The version can't be read, we can continue without it
            version = DEFAULT_VERSION;
        }

        try {
            readDatabase();
        } catch (IOException e) {
            // The database can't be read, try to continue without it
            names = new String[0];
            starts = new int[0];
            lengths = new int[0];
            offsets = new int[0];
        }
    
        return version;
private static intparseNumericZone(java.lang.String name)

        if (name == null)
            return 0;

        if (!name.startsWith("GMT"))
            return 0;

        if (name.length() == 3)
            return 0;

        int sign;
        if (name.charAt(3) == '+")
            sign = 1;
        else if (name.charAt(3) == '-")
            sign = -1;
        else
            return 0;

        int where;
        int hour = 0;
        boolean colon = false;
        for (where = 4; where < name.length(); where++) {
            char c = name.charAt(where);

            if (c == ':") {
                where++;
                colon = true;
                break;
            }

            if (c >= '0" && c <= '9")
                hour = hour * 10 + c - '0";
            else
                return 0;
        }

        int min = 0;
        for (; where < name.length(); where++) {
            char c = name.charAt(where);

            if (c >= '0" && c <= '9")
                min = min * 10 + c - '0";
            else
                return 0;
        }

        if (colon)
            return sign * (hour * 60 + min) * 60;
        else if (hour >= 100)
            return sign * ((hour / 100) * 60 + (hour % 100)) * 60;
        else
            return sign * (hour * 60) * 60;
private static intread4(byte[] data, int off)

        return ((data[off    ] & 0xFF) << 24) |
               ((data[off + 1] & 0xFF) << 16) |
               ((data[off + 2] & 0xFF) <<  8) |
               ((data[off + 3] & 0xFF) <<  0);
private static voidreadDatabase()

        if (starts != null) {
            return;
        }

        RandomAccessFile indexFile = new RandomAccessFile(INDEX_FILE_NAME, "r");
        byte[] nbuf = new byte[TZNAME_LENGTH];

        int numEntries =
            (int) (indexFile.length() / (TZNAME_LENGTH + 3*TZINT_LENGTH));

        char[] namebuf = new char[numEntries * TZNAME_LENGTH];
        int[] nameend = new int[numEntries];
        int nameoff = 0;

        starts = new int[numEntries];
        lengths = new int[numEntries];
        offsets = new int[numEntries];

        for (int i = 0; i < numEntries; i++) {
            indexFile.readFully(nbuf);
            starts[i] = indexFile.readInt();
            lengths[i] = indexFile.readInt();
            offsets[i] = indexFile.readInt();

            // Don't include null chars in the String
            int len = nbuf.length;
            for (int j = 0; j < len; j++) {
                if (nbuf[j] == 0) {
                    break;
                }
                namebuf[nameoff++] = (char) (nbuf[j] & 0xFF);
            }

            nameend[i] = nameoff;
        }

        String name = new String(namebuf, 0, nameoff);

        // Assumes the namebuf is all ASCII (so byte offsets == char offsets).
        names = new String[numEntries];
        for (int i = 0; i < numEntries; i++) {
            names[i] = name.substring(i == 0 ? 0 : nameend[i - 1],
                                      nameend[i]);
        }

        indexFile.close();
private static voidreadVersion()

        RandomAccessFile versionFile = new RandomAccessFile(VERSION_FILE_NAME, "r");
        int len = (int) versionFile.length();
        byte[] vbuf = new byte[len];
        versionFile.readFully(vbuf);
        version = new String(vbuf, 0, len, "ISO-8859-1").trim();
        versionFile.close();
public static voidsetDefault(java.util.TimeZone zone)

        /*
         * if (zone == null), the next call to getDefault will set it to the
         * the system's default time zone.
         */
        synchronized (lock) {
            defaultZone = null;
        }