java日期转字符串 字符串转日期 日期转日历 日历转日期

package com.sxito.biz.test;   import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; /**  *   * @author 落叶  *  */ public class TestStringToDate { /** * @param args */ public static void main(String[] args) { String s1 = "1991-01-01"; StringToDate(s1); Date d =new Date(); DateToString(d); Calendar calendar= DateToCalendar(d); CalendarToDate(calendar); } /** * 字符串转日期 * @param String */ private static  Date StringToDate(String String) { System.out.println("转换前类型为："+String.getClass());    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");    Date time = null;    try {        time = format.parse(String);    } catch (ParseException e) {        e.printStackTrace();    }    System.out.println("转换后类型为："+time.getClass());    return time; }  /** * 日期转换成字符串 * @param date  * @return str */ public static String DateToString(Date date) { System.out.println("转换前类型为："+date.getClass());   SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");   String string = format.format(date);   System.out.println("转换后类型为："+string.getClass());   return string; } /** * 日期转日历 * @param date * @return Calendar */ public static Calendar DateToCalendar(Date date) { System.out.println("转换前类型为："+date.getClass()); Calendar startdate=Calendar.getInstance(); startdate.setTime(date);   System.out.println("转换后类型为："+startdate.getClass());   return startdate; }  /** * 日历转日期 * @param calendar * @return Date */ public static Date CalendarToDate(Calendar calendar) { System.out.println("转换前类型为："+calendar.getClass()); Date  date= calendar.getTime();    System.out.println("转换后类型为："+date.getClass());   return date; }   }