可以使用java.util.Calendar来取得相关日期信息

import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;public class DateDemo {static SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");public static void main(String[] args) throws ParseException {String date = "2011-04-25 22:28:30";System.out.println(date);System.out.println("年份：" + getYear(date));System.out.println("月份：" + getMonth(date));System.out.println("日期：" + getDay(date));System.out.println("月初日期是: " + getMinMonthDate(date));System.out.println("月末日期是: " + getMaxMonthDate(date));}/** * 获取日期年份 * @param date * @return * @throws ParseException */public static int getYear(String date) throws ParseException{Calendar calendar = Calendar.getInstance();calendar.setTime(dateFormat.parse(date));return calendar.get(Calendar.YEAR);}/** * 获取日期月份 * @param date * @return * @throws ParseException */public static int getMonth(String date) throws ParseException{Calendar calendar = Calendar.getInstance();calendar.setTime(dateFormat.parse(date));return (calendar.get(Calendar.MONTH) + 1);}/** * 获取日期号 * @param date * @return * @throws ParseException */public static int getDay(String date) throws ParseException{Calendar calendar = Calendar.getInstance();calendar.setTime(dateFormat.parse(date));return calendar.get(Calendar.DAY_OF_MONTH);}/** * 获取月份起始日期 * @param date * @return * @throws ParseException */public static String getMinMonthDate(String date) throws ParseException{Calendar calendar = Calendar.getInstance();calendar.setTime(dateFormat.parse(date));calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMinimum(Calendar.DAY_OF_MONTH));return dateFormat.format(calendar.getTime());}/** * 获取月份最后日期 * @param date * @return * @throws ParseException */public static String getMaxMonthDate(String date) throws ParseException{Calendar calendar = Calendar.getInstance();calendar.setTime(dateFormat.parse(date));calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));return dateFormat.format(calendar.getTime());}}lxbccsu (中级程序员) 2011-03-25 不过对日期时间的操作处理，joda-time提供更好的支持
joda-time官网：
http://joda-time.sourceforge.net/

joda-time简介：
http://www.ibm.com/developerworks/cn/java/j-jodatime.html