Utility.java

/*
 * Copyright 2007 Zhang, Zheng <oldbig@gmail.com>
 * 
 * This file is part of ZOJ.
 * 
 * ZOJ 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 revision 3 of the License, or (at your option) any later revision.
 * 
 * ZOJ 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 ZOJ. if not, see
 * <http://www.gnu.org/licenses/>.
 */

package cn.edu.zju.acm.onlinejudge.util;

import java.io.IOException;
import java.net.Socket;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import org.apache.log4j.Logger;

public class Utility {

    private static DateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    private static DateFormat formatUrl =
            new SimpleDateFormat("'http://www.timeanddate.com/worldclock/fixedtime.html?"
                + "month='M'&day='d'&year='yyyy'&hour='HH'&min='mm'&sec='ss'&p1=33'");

    private static Logger logger = Logger.getLogger(Utility.class);

    private Utility() {

    }

    public static boolean validateTimestamp(String timestamp) {
        try {
            Date date = Utility.format.parse(timestamp);

            Calendar c = Calendar.getInstance();
            c.setTime(date);
            int year = c.get(Calendar.YEAR);
            if (year < 1901 || year > 3000) {
                return false;
            }
            return true;
        } catch (ParseException e) {
            return false;
        }
    }

    public static Date parseTimestamp(String timestamp) throws ParseException {
        return Utility.format.parse(timestamp);
    }

    public static String toTimestamp(Date timestamp) {
        return Utility.format.format(timestamp);
    }

    public static String toTimeUrl(Date timestamp) {
        return Utility.formatUrl.format(timestamp);
    }

    public static String toTimestampWithTimeZone(Date timestamp) {
        return Utility.format.format(timestamp) + " (GMT+8)";
    }

    public static boolean validateTime(String time) {
        String[] ss = time.split(":");
        if (ss.length != 3) {
            return false;
        }

        long h = Long.parseLong(ss[0]);
        long m = Long.parseLong(ss[1]);
        long s = Long.parseLong(ss[2]);

        if (h < 0 || m < 0 || s < 0 || m >= 60 || s >= 60) {
            return false;
        }

        return true;

    }

    public static long parseTime(String time) throws ParseException {
        if (!Utility.validateTime(time)) {
            throw new ParseException("invalid time: " + time, 0);
        }
        String[] ss = time.split(":");
        long h = Long.parseLong(ss[0]);
        long m = Long.parseLong(ss[1]);
        long s = Long.parseLong(ss[2]);

        return h * 3600 + m * 60 + s;
    }

    public static String toTime(long time) {
        return time / 3600 + ":" + time % 3600 / 60 + ":" + time % 60;
    }

    public static String toTextTime(long time) {
        long h = time / 3600;
        long m = time % 3600 / 60;
        long s = time % 60;
        StringBuilder sb = new StringBuilder();
        if (h > 0) {
            sb.append(h);
            sb.append(" Hour");
            if (h > 1) {
                sb.append("s");
            }
            sb.append(" ");
        }
        if (m > 0) {
            sb.append(m);
            sb.append(" Minute");
            if (m > 1) {
                sb.append("s");
            }
            sb.append(" ");
        }
        if (s > 0) {
            sb.append(s);
            sb.append(" Second");
            if (s > 1) {
                sb.append("s");
            }
            sb.append(" ");
        }

        return sb.toString();
    }

    public static int parseInt(String value) {
        if (value == null) {
            return -1;
        }
        try {
            return Integer.parseInt(value);
        } catch (Exception e) {
            return -1;
        }
    }

    public static long parseLong(String value) {
        if (value == null) {
            return -1;
        }
        try {
            return Long.parseLong(value);
        } catch (Exception e) {
            return -1;
        }
    }

    public static long parseLong(String value, long min, long max) {
        long ret = Utility.parseLong(value);
        if (ret < min) {
            ret = min;
        }
        if (ret > max) {
            ret = max;
        }
        return ret;
    }

    public static void closeSocket(Socket socket) {
        try {
            if (!socket.isClosed()) {
                socket.close();
            }
        } catch (IOException e) {
            Utility.logger.error("Fail to close socket", e);
        }
    }
}