java日期处理简单封装

今天没什么事情做，温习一下基本知识，在网上看到和日期处理的相关框架，什么joda，date4j等，都宣称超级强大简单易用。下下来试了下，确实都挺不错。不过自己不是经常涉及到日期操作，且涉及到的也不复杂。且不说这些库的功能强不强大，单说为了处理个时间就引入几十个类，实在有点浪费了。再说JDK提供的Calendar和SimpleDateFormat组合使用功能也还是非常强大啊。如果觉得同时使用这两个类稍显麻烦，可以稍微封装一下，即可满足大部分需求，就一个类，自己需要用到什么功能的时候，添加进去就行了。

package luojing.date;

import java.io.Serializable;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

/**
 * 日期时间处理封装
 * 
 * @author luojing
 */
public class DateTime implements Comparable<DateTime>, Serializable {

    private static final long serialVersionUID = 4715414577633839197L;
    private Calendar calendar = Calendar.getInstance();
    private SimpleDateFormat sdf = new SimpleDateFormat();

    private final String DEFAULT_DATETIME_PATTERN = "yyyy-MM-dd HH:mm:ss";
    private final String DEFAULT_DATE_PATTERN = "yyyy-MM-dd";
    private final String DEFAULT_TIME_PATTERN = "HH:mm:ss";

    public DateTime() {
    }

    public DateTime(String dateStr) {
        try {
            parse(dateStr);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public DateTime(String dateStr, TimeZone timeZone) {
        this(dateStr);
        calendar.setTimeZone(timeZone);
    }

    public DateTime(String dateStr, String pattern) {
        try {
            parse(dateStr, pattern);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public DateTime(String dateStr, String pattern, TimeZone timeZone) {
        this(dateStr, pattern);
        calendar.setTimeZone(timeZone);
    }

    public DateTime(int year, int month, int day, int hour, int minute, int second) {
        calendar.set(year, month, day, hour, minute, second);
    }

    public DateTime(int year, int month, int day, int hour, int minute, int second, TimeZone timeZone) {
        this(year, month, day, hour, minute, second);
        calendar.setTimeZone(timeZone);
    }

    public DateTime(long milliSeconds) {
        calendar.setTimeInMillis(milliSeconds);
    }

    public Calendar getCalendar() {
        return calendar;
    }

    public void setCalendar(Calendar calendar) {
        this.calendar = calendar;
    }

    public Date getDate() {
        return calendar.getTime();
    }

    public void setDate(Date date) {
        calendar.setTime(date);
    }

    public int getYear() {
        return calendar.get(Calendar.YEAR);
    }

    public void setYear(int year) {
        calendar.set(Calendar.YEAR, year);
    }

    public int getMonth() {
        return calendar.get(Calendar.MONTH);
    }

    public void setMonth(int month) {
        calendar.set(Calendar.MONTH, month);
    }

    public int getDay() {
        return calendar.get(Calendar.DAY_OF_MONTH);
    }

    public void setDay(int dayOfMonth) {
        calendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
    }

    public int getHour() {
        return calendar.get(Calendar.HOUR_OF_DAY);
    }

    public void setHour(int hour) {
        calendar.set(Calendar.HOUR_OF_DAY, hour);
    }

    public int getMinute() {
        return calendar.get(Calendar.MINUTE);
    }

    public void setMinute(int minute) {
        calendar.set(Calendar.MINUTE, minute);
    }

    public int getSecond() {
        return calendar.get(Calendar.SECOND);
    }

    public void setSecond(int second) {
        calendar.set(Calendar.SECOND, second);
    }

    public long getTimeInMilliSeconds() {
        return calendar.getTimeInMillis();
    }

    public void setTimeInMilliSeconds(long milliSeconds) {
        calendar.setTimeInMillis(milliSeconds);
    }

    public TimeZone getTimeZone() {
        return calendar.getTimeZone();
    }

    public void setTimeZone(TimeZone timeZone) {
        calendar.setTimeZone(timeZone);
    }

    /**
     * 使用默认格式解析日期字符串
     * 
     * @param dateStr
     * @throws Exception
     */
    public void parse(String dateStr) throws Exception {
        try {
            parse(dateStr, DEFAULT_DATETIME_PATTERN);
        } catch (Exception e) {
            try {
                parse(dateStr, DEFAULT_DATE_PATTERN);
            } catch (Exception e1) {
                try {
                    parse(dateStr, DEFAULT_TIME_PATTERN);
                } catch (Exception e2) {
                    throw new Exception("the date string [" + dateStr + "] could not be parsed");
                }
            }
        }

    }

    /**
     * 使用给定模式解析日期字符串
     * 
     * @param dateStr
     * @param pattern
     * @throws Exception
     */
    public void parse(String dateStr, String pattern) throws Exception {
        if (dateStr == null) {
            throw new NullPointerException("date string could not be null");
        }

        if (pattern == null) {
            throw new NullPointerException("the pattern string could not be null");
        }

        try {
            sdf.applyPattern(pattern);
            sdf.parse(dateStr);
        } catch (ParseException e) {
            throw new Exception("the date string [" + dateStr + "] could not be parsed with the pattern [" + pattern + "]");
        }
        calendar = sdf.getCalendar();
    }

    /**
     * 格式化当前DateTime对象代表的时间
     * 
     * @param pattern
     * @return
     */
    public String format(String pattern) {
        sdf.applyPattern(pattern);
        return sdf.format(calendar.getTime());
    }

    /**
     * 获取默认格式日期字符串
     * 
     * @return
     */
    public String toDateTimeString() {
        sdf.applyPattern(DEFAULT_DATETIME_PATTERN);
        return sdf.format(calendar.getTime());
    }

    @Override
    public int compareTo(DateTime otherDateTime) {
        return calendar.compareTo(otherDateTime.getCalendar());
    }

    /**
     * 是否闰年
     * 
     * @return
     */
    public boolean isLeapYear() {
        int year = getYear();
        boolean result = false;
        if (year % 100 == 0) {
            if (year % 400 == 0) {
                result = true;
            }
        } else if (year % 4 == 0) {
            result = true;
        }
        return result;
    }

    /**
     * 获取星期
     * 
     * @return
     */
    public int getDayOfWeek() {
        return calendar.get(Calendar.DAY_OF_WEEK);
    }

    /**
     * 是否周末
     * 
     * @return
     */
    public boolean isWeekend() {
        int dayOfWeek = getDayOfWeek();
        return dayOfWeek == 1 || dayOfWeek == 7;
    }

    /**
     * 当前DateTime对象月份天数
     * 
     * @return
     */
    public int getDayNumsInMonth() {
        Calendar c = (Calendar) calendar.clone();
        c.set(Calendar.DAY_OF_MONTH, 1);
        c.roll(Calendar.DAY_OF_MONTH, -1);
        return c.get(Calendar.DAY_OF_MONTH);
    }

    /**
     * 两个日期之间间隔天数
     * 
     * @param otherDateTime
     * @return
     */
    public int dayNumFrom(DateTime otherDateTime) {
        long millis = Math.abs(getTimeInMilliSeconds() - otherDateTime.getTimeInMilliSeconds());
        int days = (int) Math.floor(millis / 86400000);
        return days;
    }

    public boolean lessThan(DateTime otherDateTime) {
        return compareTo(otherDateTime) < 0;
    }

    public boolean greaterThan(DateTime otherDateTime) {
        return compareTo(otherDateTime) > 0;
    }

    public boolean equal(DateTime otherDateTime) {
        return compareTo(otherDateTime) == 0;
    }

    /**
     * 当前时间基础上增加秒数(负数时为减)
     * 
     * @param amount
     */
    public void plusSecond(int amount) {
        calendar.add(Calendar.SECOND, amount);
    }

    public void plusMinute(int amount) {
        calendar.add(Calendar.MINUTE, amount);
    }

    public void plusHour(int amount) {
        calendar.add(Calendar.HOUR, amount);
    }

    public void plusDays(int amount) {
        calendar.add(Calendar.DAY_OF_MONTH, amount);
    }

    public void plusMonth(int amount) {
        calendar.add(Calendar.MONTH, amount);
    }

    public void plusYear(int amount) {
        calendar.add(Calendar.YEAR, amount);
    }

    public void plus(int year, int month, int day, int hour, int minute, int second) {
        plusYear(year);
        plusMonth(month);
        plusDays(day);
        plusHour(hour);
        plusMinute(minute);
        plusSecond(second);
    }

}

测试：

package luojing.date;

import java.util.Date;

public class DateTimeTest {

    public static void main(String[] args) throws Exception {
        DateTime dateTime = new DateTime();
        DateTime dateTime2 = new DateTime("2013-12-12");
        System.out.println("默认格式输出：" + dateTime.toDateTimeString());
        System.out.println("是否闰年:" + dateTime.isLeapYear());
        System.out.println("自定义格式输出：" + dateTime.format("yyyy-MM-dd"));
        System.out.println("输出到毫秒：" + dateTime.format("yyyy-MM-dd HH:mm:ss.SSS"));
        System.out.println("某月天数：" + dateTime.getDayNumsInMonth());
        System.out.println("星期：" + dateTime.getDayOfWeek());//1:星期日,7:星期六
        System.out.println("是否周末：" + dateTime.isWeekend());
        System.out.println("相距：" + dateTime.dayNumFrom(dateTime2) + "天");
        
        dateTime.plusMonth(1);
        System.out.println("增加一个月后的datetime: " + dateTime.toDateTimeString());
        dateTime.plus(0, 0, 2, 4, 4, 5);
        System.out.println("增加 XXX后的datetime: " + dateTime.toDateTimeString());
        System.out.println("毫秒数：" + dateTime.getTimeInMilliSeconds());
        
        //DateTime转换为Date
        Date date = dateTime.getDate();
        System.out.println( dateTime.getTimeInMilliSeconds() == date.getTime());
    }
}

输出：

默认格式输出：2013-09-25 19:16:15
是否闰年:false
自定义格式输出：2013-09-25
输出到毫秒：2013-09-25 19:16:15.278
某月天数：30
星期：4
是否周末：false
相距：77天
增加一个月后的datetime: 2013-10-25 19:16:15
增加 XXX后的datetime: 2013-10-27 23:20:20
毫秒数：1382887220278
true

本人使用到日期处理相关的操作，大多就是格式化时间和时间之间的比较。这个封装已经完全能够满足我的日常需要了，再说，即使找不到合适的封装方法，还可以直接获取包装的calendar对象来做处理。