Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * Copyright (C) 2011,2012  Southern Storm Software, Pty Ltd.
 *
 * This program 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */

import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.TimeZone;

public class Main {
    private static TimeZone cachedTimeZone = null;
    private static int cachedOffset = 0;

    /**
     * Parses a date/time string from within an XMLTV stream.  Only the local
     * time part of the value is parsed. Timezone specifications are ignored.
     * 
     * @param str the string
     * @param convertTimezone true to convert date/time values to local time
     * @return the date/time value as a Calendar object
     */
    public static Calendar parseDateTime(String str, boolean convertTimezone) {
        // Format looks like: 20111209060000 +1100
        if (str == null)
            return null;
        int year = parseField(str, 0, 4);
        int month = parseField(str, 4, 2);
        int day = parseField(str, 6, 2);
        int hour = parseField(str, 8, 2);
        int minute = parseField(str, 10, 2);
        int second = parseField(str, 12, 2);
        if (convertTimezone) {
            if (cachedTimeZone == null) {
                cachedTimeZone = TimeZone.getDefault();
                cachedOffset = cachedTimeZone.getOffset(System.currentTimeMillis());
            }
            int tz = parseTZField(str, 14);
            if (tz != cachedOffset) {
                Calendar calendar = new GregorianCalendar(year, month - 1, day, hour, minute, second);
                calendar.add(Calendar.MILLISECOND, cachedOffset - tz);
                return calendar;
            }
        }
        return new GregorianCalendar(year, month - 1, day, hour, minute, second);
    }

    /**
     * Parses a fixed-length numeric field out of a string.
     * 
     * @param str the string
     * @param posn the starting position within the string
     * @param length the length of the field
     * @return the numeric value
     */
    public static int parseField(String str, int posn, int length) {
        int value = 0;
        while (length-- > 0) {
            if (posn >= str.length())
                break;
            char ch = str.charAt(posn++);
            if (ch >= '0' && ch <= '9')
                value = value * 10 + ch - '0';
        }
        return value;
    }

    private static int parseTZField(String str, int posn) {
        while (posn < str.length() && str.charAt(posn) == ' ') {
            ++posn;
        }
        if (posn >= str.length())
            return cachedOffset;
        boolean positive;
        if (str.charAt(posn) == '+') {
            positive = true;
            ++posn;
        } else if (str.charAt(posn) == '-') {
            positive = false;
            ++posn;
        } else {
            return cachedOffset;
        }
        int raw = parseField(str, posn, 4);
        int value = ((raw / 100) * 60 + (raw % 100)) * (60 * 1000);
        if (positive)
            return value;
        else
            return -value;
    }
}