java 中的日期操作工具类，java日期操作工具类,package com.

java 中的日期操作工具类，java日期操作工具类,package com.

package com.ccfn.utils;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;/** *  * @author ccfn * 对日期类型进行需要的转换 * */public class DateFormatUtil {    private static String patter = "yyyy-MM-dd";    private static SimpleDateFormat sdf = new SimpleDateFormat(patter);    /**     * 获得日期字符中的年份     */    public static String getYearByString(String str){        Date date = convertStringToDate(str);        Calendar cal = convertDateToCalendar(date);        return String.valueOf(cal.get(Calendar.YEAR));    }    /**     * 获得日期字符串中的月份     * @param str     * @return     */    public static String getMonthByString(String str){        Date date = convertStringToDate(str);        Calendar cal = convertDateToCalendar(date);        return String.valueOf(cal.get(Calendar.MONTH)+ 1);    }    /**     * 获得日期字符串中的天     * @param str     * @return     */    public static String getDayByString(String str){        Date date = convertStringToDate(str);        Calendar cal = convertDateToCalendar(date);        return String.valueOf(cal.get(Calendar.DAY_OF_WEEK));    }    /**     * 根据日期字符串     * @param str     * @return     */    public static String getPartByString(String str){        int temp = Integer.parseInt(getMonthByString(str))+ 1;        if(temp <= 6){            return "1";        }        return "2";    }    /**     * 日期转换成Calendar     */    public static Calendar convertDateToCalendar(Date date){        Calendar cal = Calendar.getInstance();         cal.setTime(date);        return cal;    }    /**     * 日期转换成字符串     */    public static String convertDateToString(Date date){        return sdf.format(date);    }    /**     *      * @param sDate 日期类型的字符串     * @return 日期类型     *      * 字符串转换成日期     */    public static Date convertStringToDate(String sDate){        Date date = null;        try {            date = sdf.parse(sDate);        } catch (ParseException e) {            e.printStackTrace();        }        return date;    }    /**     *      * @param 改变格式类型     */    public static void changePattern(String patter){        DateFormatUtil.patter = patter;        DateFormatUtil.sdf = new SimpleDateFormat(patter);    }    public static String getToday() {        Calendar cl = Calendar.getInstance();        String month = "";        String day = "";        String today = "";        String today2 = "";        int m = cl.get(Calendar.MONTH) + 1;        if (m < 10) {            month = "0" + String.valueOf(m);        }        else {            month = String.valueOf(m);        }        int d = cl.get(Calendar.DATE);        if (d < 10) {            day = "0" + String.valueOf(d);        }        else {            day = String.valueOf(d);        }        today = cl.get(Calendar.YEAR) +  month + day + cl.get(Calendar.HOUR_OF_DAY) + cl.get(Calendar.MINUTE)+ cl.get(Calendar.SECOND);        today2 = cl.get(Calendar.YEAR) +"-"+  month +"-"+ day +" "+ cl.get(Calendar.HOUR_OF_DAY) +":"+ cl.get(Calendar.MINUTE)+ ":"+cl.get(Calendar.SECOND);        return today2;    }    public static void main(String[] args) {        //changePattern("yyyy-MM-dd hh:mm:ss");        //System.out.println(DateFormatUtil.convertDateToString(new Date()));        Calendar cal = DateFormatUtil.convertDateToCalendar(new Date());        System.out.println(cal.getTime());        cal.add(Calendar.DAY_OF_WEEK, 3);        System.out.println(cal.getTime());    }}//该片段来自于http://byrx.net