关于日期格式转换类

/**
 * Title:
 * Description:  ots
 * Copyright:    Copyright (c) 2001
 * Company:      NMT
 * @author Colin
 * @version 1.0
 */
import java.sql.Timestamp;
import java.util.*;
import java.text.*;

public class FormatUtil {

    /**
	 * @param Calendar
	 * @return String 2001/12/13 Format
	 */
    public static String CalendarToStr(Calendar cal) {
        SimpleDateFormat format = new SimpleDateFormat("yyyy/MM/dd");
        if (cal != null) {
            Date date = cal.getTime();
            return format.format(date);
        } else {
            return "";
        }
    }

    /**
	 * @param Calendar
	 * @return a Sunday Calendar in the Week
	 */
    public static Calendar starCalOfWeek(Calendar day) {
		int temp = day.get(Calendar.DAY_OF_WEEK);
        switch (temp) {
            case 1:
                return day;
            case 2:
                day.add(Calendar.DATE, -1);
                return day;
            case 3:
                 day.add(Calendar.DATE, -2);
                return day;
            case 4:
                 day.add(Calendar.DATE, -3);
                return day;
            case 5:
                 day.add(Calendar.DATE, -4);
                return day;
            case 6:
                 day.add(Calendar.DATE, -5);
                return day;
            case 7:
                 day.add(Calendar.DATE, -6);
                return day;
            default:
                return  day;;
        }
    }

    /**
	 * @param Calendar
	 * @return a Satday Calendar in the Week
	 */
    public static Calendar endCalOfWeek(Calendar day) {
		int temp = day.get(Calendar.DAY_OF_WEEK);
        switch (temp) {
            case 1:
                 day.add(Calendar.DATE, 6);
                return day;
            case 2:
                day.add(Calendar.DATE, 5);
                return day;
            case 3:
                day.add(Calendar.DATE, 4);
                return day;
            case 4:
                day.add(Calendar.DATE, 3);
                return day;
            case 5:
                day.add(Calendar.DATE, 2);
                return day;
            case 6:
                day.add(Calendar.DATE, 1);
                return day;
            case 7:
                return day;
            default:
                return day;;
        }
    }

	public static Date StrToDate(String str) {
        if(str.length() == 0) {
            return null;
        }
        int start = str.indexOf('/');
        String year = str.substring(0, start);
        start ++;
        int start1 = str.indexOf('/', start);
        String month = str.substring(start, start1);
        String day = str.substring(start1 + 1);
        Date date = new Date();
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.set(Calendar.YEAR, Integer.parseInt(year));
        cal.set(Calendar.MONTH, Integer.parseInt(month) - 1);
        cal.set(Calendar.DATE, Integer.parseInt(day));
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
        System.out.println(sdf.format(cal.getTime()));
        return cal.getTime();
	}

	public static Calendar StrToCalendar(String str) {
        if(str.length() == 0) {
            return null;
        }
        int start = str.indexOf('/');
        String year = str.substring(0, start);
        start ++;
        int start1 = str.indexOf('/', start);
        String month = str.substring(start, start1);
        String day = str.substring(start1 + 1);
        Date date = new Date();
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.set(Calendar.MONTH, Integer.parseInt(month) - 1);
        cal.set(Calendar.DATE, Integer.parseInt(day));
        return cal;
	}

    /**
	 * @param Calendar
	 * @return String Sun Mon etc. Format
	 */
    public static String dayOfWeek(Calendar day) {
		int temp = day.get(Calendar.DAY_OF_WEEK);
        switch (temp) {
            case 1:
                return "Sun";
            case 2:
                return "Mon";
            case 3:
                return "Tue";
            case 4:
                return "Wed";
            case 5:
                return "Thu";
            case 6:
                return "Fri";
            case 7:
                return "Sat";
            default:
                return "";
        }
	}

    /**
	 * @param String Date Format 2001/12/13
	 * @return String Sun Mon etc. Format
	 */
    public static String dayOfWeek(String inDay) {
        Calendar cal = Calendar.getInstance();

        cal.setTime(StrToDate(inDay));
		int temp = cal.get(Calendar.DAY_OF_WEEK);
        switch (temp) {
            case 1:
                return "Sun";
            case 2:
                return "Mon";
            case 3:
                return "Tue";
            case 4:
                return "Wed";
            case 5:
                return "Thu";
            case 6:
                return "Fri";
            case 7:
                return "Sat";
            default:
                return "";
        }
	}

    public static Timestamp StrToTimestamp(String timestampStr,String pattern)
            throws ParseException {
        java.util.Date date = null;
        SimpleDateFormat format = new SimpleDateFormat(pattern);
        try {
            date = format.parse(timestampStr);
        } catch (ParseException e) {
                throw e;
        }
        return date == null ? null : new Timestamp(date.getTime());
    }

}