package com.xuyigang1234.chp05.sec01;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;public class TestSimpleDateFormat {        /**      * 将日期对象格式化为指定格式的日期字符串     * @param date 传入的日期对象     * @param format 格式     * @return     */    public static String formateDate(Date date,String geshi) {        String result="";        SimpleDateFormat sdf= new SimpleDateFormat(geshi);        if(date !=null) {            result=sdf.format(date);                    }        return result;        }    /**             * 将日期字符串转换成一个日期对象      * @param dateStr 日期字符串     * @param format 格式     * @return     * @throws ParseException      */    public static Date formateD(String dateStr,String geshi) throws ParseException {        SimpleDateFormat sdf= new SimpleDateFormat(geshi);        return sdf.parse(dateStr);    }    public static void main(String[] args) throws ParseException {        Date date= new Date();        SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd");        String date1 = sdf.format(date);        System.out.println(date1);        //formateDate        String date2 = formateDate(date,"yyyy-MM-dd HH:mm:ss");        System.out.println(date2);        //parse        String dataStr="1989-11-02 18:01:41";        Date date3 = formateD(dataStr,"yyyy-MM-dd HH:mm:ss");        System.out.println(formateDate(date3,"yyyy-MM-dd HH:mm:ss"));    }}

输出：  2018-11-222018-11-22 22:31:191989-11-02 18:01:41