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Java example source code file (Zoneinfo.java)

This example Java source code file (Zoneinfo.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

filereader, gmt, hashmap, illegalargumentexception, list, map, rule, rulerec, string, stringtokenizer, timezone, util, zone, zoneinfo, zonerec

The Zoneinfo.java Java example source code

/*
 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;

/**
 * Zoneinfo provides javazic compiler front-end functionality.
 * @since 1.4
 */
class Zoneinfo {

    private static final int minYear = 1900;
    private static final int maxYear = 2037;
    private static final long minTime = Time.getLocalTime(minYear, Month.JANUARY, 1, 0);
    private static int startYear = minYear;
    private static int endYear = maxYear;

    /**
     * True if javazic should generate a list of SimpleTimeZone
     * instances for the SimpleTimeZone-based time zone support.
     */
    static boolean isYearForTimeZoneDataSpecified = false;

    /**
     * Zone name to Zone mappings
     */
    private Map<String,Zone> zones;

    /**
     * Rule name to Rule mappings
     */
    private Map<String,Rule> rules;

    /**
     * Alias name to real name mappings
     */
    private Map<String,String> aliases;

    /**
     * Constracts a Zoneinfo.
     */
    Zoneinfo() {
        zones = new HashMap<String,Zone>();
        rules = new HashMap<String,Rule>();
        aliases = new HashMap<String,String>();
    }

    /**
     * Adds the given zone to the list of Zones.
     * @param zone Zone to be added to the list.
     */
    void add(Zone zone) {
        String name = zone.getName();
        zones.put(name, zone);
    }

    /**
     * Adds the given rule to the list of Rules.
     * @param rule Rule to be added to the list.
     */
    void add(Rule rule) {
        String name = rule.getName();
        rules.put(name, rule);
    }

    /**
     * Puts the specifid name pair to the alias table.
     * @param name1 an alias time zone name
     * @param name2 the real time zone of the alias name
     */
    void putAlias(String name1, String name2) {
        aliases.put(name1, name2);
    }

    /**
     * Sets the given year for SimpleTimeZone list output.
     * This method is called when the -S option is specified.
     * @param year the year for which SimpleTimeZone list should be generated
     */
    static void setYear(int year) {
        setStartYear(year);
        setEndYear(year);
        isYearForTimeZoneDataSpecified = true;
    }

    /**
     * Sets the start year.
     * @param year the start year value
     * @throws IllegalArgumentException if the specified year value is
     * smaller than the minimum year or greater than the end year.
     */
    static void setStartYear(int year) {
        if (year < minYear || year > endYear) {
            throw new IllegalArgumentException("invalid start year specified: " + year);
        }
        startYear = year;
    }

    /**
     * @return the start year value
     */
    static int getStartYear() {
        return startYear;
    }

    /**
     * Sets the end year.
     * @param year the end year value
     * @throws IllegalArgumentException if the specified year value is
     * smaller than the start year or greater than the maximum year.
     */
    static void setEndYear(int year) {
        if (year < startYear || year > maxYear) {
            throw new IllegalArgumentException();
        }
        endYear = year;
    }

    /**
     * @return the end year value
     */
    static int getEndYear() {
        return endYear;
    }

    /**
     * @return the minimum year value
     */
    static int getMinYear() {
        return minYear;
    }

    /**
     * @return the maximum year value
     */
    static int getMaxYear() {
        return maxYear;
    }

    /**
     * @return the alias table
     */
    Map<String,String> getAliases() {
        return aliases;
    }

    /**
     * @return the Zone list
     */
    Map<String,Zone> getZones() {
        return zones;
    }

    /**
     * @return a Zone specified by name.
     * @param name a zone name
     */
    Zone getZone(String name) {
        return zones.get(name);
    }

    /**
     * @return a Rule specified by name.
     * @param name a rule name
     */
    Rule getRule(String name) {
        return rules.get(name);
    }

    private static String line;

    private static int lineNum;

    /**
     * Parses the specified time zone data file and creates a Zoneinfo
     * that has all Rules, Zones and Links (aliases) information.
     * @param fname the time zone data file name
     * @return a Zoneinfo object
     */
    static Zoneinfo parse(String fname) {
        BufferedReader in = null;
        try {
            FileReader fr = new FileReader(fname);
            in = new BufferedReader(fr);
        } catch (FileNotFoundException e) {
            panic("can't open file: "+fname);
        }
        Zoneinfo zi = new Zoneinfo();
        boolean continued = false;
        Zone zone = null;
        String l;
        lineNum = 0;

        try {
            while ((line = in.readLine()) != null) {
                lineNum++;
                // skip blank and comment lines
                if (line.length() == 0 || line.charAt(0) == '#') {
                    continue;
                }

                // trim trailing comments
                int rindex = line.lastIndexOf('#');
                if (rindex != -1) {
                    // take the data part of the line
                    l = line.substring(0, rindex);
                } else {
                    l = line;
                }

                StringTokenizer tokens = new StringTokenizer(l);
                if (!tokens.hasMoreTokens()) {
                    continue;
                }
                String token = tokens.nextToken();

                if (continued || "Zone".equals(token)) {
                    if (zone == null) {
                        if (!tokens.hasMoreTokens()) {
                            panic("syntax error: zone no more token");
                        }
                        token = tokens.nextToken();
                        // if the zone name is in "GMT+hh" or "GMT-hh"
                        // format, ignore it due to spec conflict.
                        if (token.startsWith("GMT+") || token.startsWith("GMT-")) {
                            continue;
                        }
                        zone = new Zone(token);
                    } else {
                        // no way to push the current token back...
                        tokens = new StringTokenizer(l);
                    }

                    ZoneRec zrec = ZoneRec.parse(tokens);
                    zrec.setLine(line);
                    zone.add(zrec);
                    if ((continued = zrec.hasUntil()) == false) {
                        if (Zone.isTargetZone(zone.getName())) {
                            // zone.resolve(zi);
                            zi.add(zone);
                        }
                        zone = null;
                    }
                } else if ("Rule".equals(token)) {
                    if (!tokens.hasMoreTokens()) {
                        panic("syntax error: rule no more token");
                    }
                    token = tokens.nextToken();
                    Rule rule = zi.getRule(token);
                    if (rule == null) {
                        rule = new Rule(token);
                        zi.add(rule);
                    }
                    RuleRec rrec = RuleRec.parse(tokens);
                    rrec.setLine(line);
                    rule.add(rrec);
                } else if ("Link".equals(token)) {
                    // Link <newname> 
                    try {
                        String name1 = tokens.nextToken();
                        String name2 = tokens.nextToken();

                        // if the zone name is in "GMT+hh" or "GMT-hh"
                        // format, ignore it due to spec conflict with
                        // custom time zones. Also, ignore "ROC" for
                        // PC-ness.
                        if (name2.startsWith("GMT+") || name2.startsWith("GMT-")
                            || "ROC".equals(name2)) {
                            continue;
                        }
                        zi.putAlias(name2, name1);
                    } catch (Exception e) {
                        panic("syntax error: no more token for Link");
                    }
                }
            }
            in.close();
        } catch (IOException ex) {
            panic("IO error: " + ex.getMessage());
        }

        return zi;
    }

    /**
     * Interprets a zone and constructs a Timezone object that
     * contains enough information on GMT offsets and DST schedules to
     * generate a zone info database.
     *
     * @param zoneName the zone name for which a Timezone object is
     * constructed.
     *
     * @return a Timezone object that contains all GMT offsets and DST
     * rules information.
     */
    Timezone phase2(String zoneName) {
        Timezone tz = new Timezone(zoneName);
        Zone zone = getZone(zoneName);
        zone.resolve(this);

        // TODO: merge phase2's for the regular and SimpleTimeZone ones.
        if (isYearForTimeZoneDataSpecified) {
            ZoneRec zrec = zone.get(zone.size()-1);
            tz.setLastZoneRec(zrec);
            tz.setRawOffset(zrec.getGmtOffset());
            if (zrec.hasRuleReference()) {
                /*
                 * This part assumes that the specified year is covered by
                 * the rules referred to by the last zone record.
                 */
                List<RuleRec> rrecs = zrec.getRuleRef().getRules(startYear);

                if (rrecs.size() == 2) {
                    // make sure that one is a start rule and the other is
                    // an end rule.
                    RuleRec r0 = rrecs.get(0);
                    RuleRec r1 = rrecs.get(1);
                    if (r0.getSave() == 0 && r1.getSave() > 0) {
                        rrecs.set(0, r1);
                        rrecs.set(1, r0);
                    } else if (!(r0.getSave() > 0 && r1.getSave() == 0)) {
                        rrecs = null;
                        Main.error(zoneName + ": rules for " +  startYear + " not found.");
                    }
                } else {
                    rrecs = null;
                }
                if (rrecs != null) {
                    tz.setLastRules(rrecs);
                }
            }
            return tz;
        }

        int gmtOffset;
        int year = minYear;
        int fromYear = year;
        long fromTime = Time.getLocalTime(startYear,
                                          Month.JANUARY,
                                          1, 0);

        // take the index 0 for the GMT offset of the last zone record
        ZoneRec zrec = zone.get(zone.size()-1);
        tz.getOffsetIndex(zrec.getGmtOffset());

        int currentSave = 0;
        boolean usedZone;
        for (int zindex = 0; zindex < zone.size(); zindex++) {
            zrec = zone.get(zindex);
            usedZone = false;
            gmtOffset = zrec.getGmtOffset();
            int stdOffset = zrec.getDirectSave();

            // If this is the last zone record, take the last rule info.
            if (!zrec.hasUntil()) {
                tz.setRawOffset(gmtOffset, fromTime);
                if (zrec.hasRuleReference()) {
                    tz.setLastRules(zrec.getRuleRef().getLastRules());
                } else if (stdOffset != 0) {
                    // in case the last rule is all year round DST-only
                    // (Asia/Amman once announced this rule.)
                    tz.setLastDSTSaving(stdOffset);
                }
            }
            if (!zrec.hasRuleReference()) {
                if (!zrec.hasUntil() || zrec.getUntilTime(stdOffset) >= fromTime) {
                    tz.addTransition(fromTime,
                                     tz.getOffsetIndex(gmtOffset+stdOffset),
                                     tz.getDstOffsetIndex(stdOffset));
                    usedZone = true;
                }
                currentSave = stdOffset;
                // optimization in case the last rule is fixed.
                if (!zrec.hasUntil()) {
                    if (tz.getNTransitions() > 0) {
                        if (stdOffset == 0) {
                            tz.setDSTType(Timezone.X_DST);
                        } else {
                            tz.setDSTType(Timezone.LAST_DST);
                        }
                        long time = Time.getLocalTime(maxYear,
                                                      Month.JANUARY, 1, 0);
                        time -= zrec.getGmtOffset();
                        tz.addTransition(time,
                                         tz.getOffsetIndex(gmtOffset+stdOffset),
                                         tz.getDstOffsetIndex(stdOffset));
                        tz.addUsedRec(zrec);
                    } else {
                        tz.setDSTType(Timezone.NO_DST);
                    }
                    break;
                }
            } else {
                Rule rule = zrec.getRuleRef();
                boolean fromTimeUsed = false;
                currentSave = 0;
            year_loop:
                for (year = getMinYear(); year <= endYear; year++) {
                    if (zrec.hasUntil() && year > zrec.getUntilYear()) {
                        break;
                    }
                    List<RuleRec> rules = rule.getRules(year);
                    if (rules.size() > 0) {
                        for (int i = 0; i < rules.size(); i++) {
                            RuleRec rrec = rules.get(i);
                            long transition = rrec.getTransitionTime(year,
                                                                     gmtOffset,
                                                                     currentSave);
                            if (zrec.hasUntil()) {
                                if (transition >= zrec.getUntilTime(currentSave)) {
                                    break year_loop;
                                }
                            }

                            if (fromTimeUsed == false) {
                                if (fromTime <= transition) {
                                    fromTimeUsed = true;

                                    if (fromTime != minTime) {
                                        int prevsave;

                                        ZoneRec prevzrec = zone.get(zindex - 1);

                                        // See if until time in the previous
                                        // ZoneRec is the same thing as the
                                        // local time in the next rule.
                                        // (examples are Asia/Ashkhabad in 1991,
                                        // Europe/Riga in 1989)

                                        if (i > 0) {
                                            prevsave = rules.get(i-1).getSave();
                                        } else {
                                            List<RuleRec> prevrules = rule.getRules(year-1);

                                            if (prevrules.size() > 0) {
                                                prevsave = prevrules.get(prevrules.size()-1).getSave();
                                            } else {
                                                prevsave = 0;
                                            }
                                        }

                                        if (rrec.isSameTransition(prevzrec, prevsave, gmtOffset)) {
                                            currentSave = rrec.getSave();
                                            tz.addTransition(fromTime,
                                                         tz.getOffsetIndex(gmtOffset+currentSave),
                                                         tz.getDstOffsetIndex(currentSave));
                                            tz.addUsedRec(rrec);
                                            usedZone = true;
                                            continue;
                                        }
                                        if (!prevzrec.hasRuleReference()
                                            || rule != prevzrec.getRuleRef()
                                            || (rule == prevzrec.getRuleRef()
                                                && gmtOffset != prevzrec.getGmtOffset())) {
                                            int save = (fromTime == transition) ? rrec.getSave() : currentSave;
                                            tz.addTransition(fromTime,
                                                         tz.getOffsetIndex(gmtOffset+save),
                                                         tz.getDstOffsetIndex(save));
                                            tz.addUsedRec(rrec);
                                            usedZone = true;
                                        }
                                    } else {  // fromTime == minTime
                                        int save = rrec.getSave();
                                        tz.addTransition(minTime,
                                                         tz.getOffsetIndex(gmtOffset),
                                                         tz.getDstOffsetIndex(0));

                                        tz.addTransition(transition,
                                                         tz.getOffsetIndex(gmtOffset+save),
                                                         tz.getDstOffsetIndex(save));

                                        tz.addUsedRec(rrec);
                                        usedZone = true;
                                    }
                                } else if (year == fromYear && i == rules.size()-1) {
                                    int save = rrec.getSave();
                                    tz.addTransition(fromTime,
                                                     tz.getOffsetIndex(gmtOffset+save),
                                                     tz.getDstOffsetIndex(save));
                                }
                            }

                            currentSave = rrec.getSave();
                            if (fromTime < transition) {
                                tz.addTransition(transition,
                                                 tz.getOffsetIndex(gmtOffset+currentSave),
                                                 tz.getDstOffsetIndex(currentSave));
                                tz.addUsedRec(rrec);
                                usedZone = true;
                            }
                        }
                    } else {
                        if (year == fromYear) {
                            tz.addTransition(fromTime,
                                             tz.getOffsetIndex(gmtOffset+currentSave),
                                             tz.getDstOffsetIndex(currentSave));
                            fromTimeUsed = true;
                        }
                        if (year == endYear && !zrec.hasUntil()) {
                            if (tz.getNTransitions() > 0) {
                                // Assume that this Zone stopped DST
                                tz.setDSTType(Timezone.X_DST);
                                long time = Time.getLocalTime(maxYear, Month.JANUARY,
                                                              1, 0);
                                time -= zrec.getGmtOffset();
                                tz.addTransition(time,
                                                 tz.getOffsetIndex(gmtOffset),
                                                 tz.getDstOffsetIndex(0));
                                usedZone = true;
                            } else {
                                tz.setDSTType(Timezone.NO_DST);
                            }
                        }
                    }
                }
            }
            if (usedZone) {
                tz.addUsedRec(zrec);
            }
            if (zrec.hasUntil() && zrec.getUntilTime(currentSave) > fromTime) {
                fromTime = zrec.getUntilTime(currentSave);
                fromYear = zrec.getUntilYear();
                year = zrec.getUntilYear();
            }
        }

        if (tz.getDSTType() == Timezone.UNDEF_DST) {
            tz.setDSTType(Timezone.DST);
        }
        tz.optimize();
        tz.checksum();
        return tz;
    }

    private static void panic(String msg) {
        Main.panic(msg);
    }
}

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