Java 获取指定日期的方法总结

原文地址：http://bdcwl.blog.163.com/blog/static/765222652009104171521/

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date = sdf.parse("2009-11-04");//String-->Date
String sdate = sdf.format(date );// Data-->String

---

TimeTest 类

package com.test;
import java.text.DateFormat;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
public class TimeTest {
//用来全局控制 上一周，本周，下一周的周数变化
private int weeks = 0;
private int MaxDate;//一月最大天数
private int MaxYear;//一年最大天数
/**
* @param args
*/
public static void main(String[] args) {
	TimeTest tt = new TimeTest();
	System.out.println("得到6个月后的日期:"+tt .getAfterMonth(6);
	System.out.println("获取当天日期:"+tt.getNowTime("yyyy-MM-dd"));
	System.out.println("获取本周一日期:"+tt.getMondayOFWeek());
	System.out.println("获取本周日的日期~:"+tt.getCurrentWeekday());
	System.out.println("获取上周一日期:"+tt.getPreviousWeekday());
	System.out.println("获取上周日日期:"+tt.getPreviousWeekSunday());
	System.out.println("获取下周一日期:"+tt.getNextMonday());
	System.out.println("获取下周日日期:"+tt.getNextSunday());
	System.out.println("获得相应周的周六:"+tt.getNowTime("yyyy-MM-dd"));
	System.out.println("获取本月第一天日期:"+tt.getFirstDayOfMonth());
	System.out.println("获取本月最后一天日期:"+tt.getDefaultDay());
	System.out.println("获取上月第一天日期:"+tt.getPreviousMonthFirst());
	System.out.println("获取上月最后一天的日期:"+tt.getPreviousMonthEnd());
	System.out.println("获取下月第一天日期:"+tt.getNextMonthFirst());
	System.out.println("获取下月最后一天日期:"+tt.getNextMonthEnd());
	System.out.println("获取本年的第一天日期:"+tt.getCurrentYearFirst());
	System.out.println("获取本年最后一天日期:"+tt.getCurrentYearEnd());
	System.out.println("获取去年的第一天日期:"+tt.getPreviousYearFirst());
	System.out.println("获取去年的最后一天日期:"+tt.getPreviousYearEnd());
	System.out.println("获取明年第一天日期:"+tt.getNextYearFirst());
	System.out.println("获取明年最后一天日期:"+tt.getNextYearEnd());
	System.out.println("获取两个日期之间间隔天数2008-12-1~2008-
	9.29:"+TimeTest.getTwoDay("2008-12-1","2008-9-29"));
}
/**
* 得到指定月后（前）的日期 参数传负数即可
*/
public static String  getAfterMonth(int month) {
	Calendar c = Calendar.getInstance();//获得一个日历的实例
	SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
	Date date = null;
	try{
		date = sdf.parse("2009-11-04");//初始日期
	}catch(Exception e){
	}
	c.setTime(date);//设置日历时间
	c.add(Calendar.MONTH,month);//在日历的月份上增加6个月
	String strDate = sdf.format(c.getTime()));//的到你想要得6个月后的日期
	return strDate;
 }
/**
* 得到二个日期间的间隔天数
*/
public static String getTwoDay(String sj1, String sj2) {
	SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");
	long day = 0;
	try {
		java.util.Date date = myFormatter.parse(sj1);
		java.util.Date mydate = myFormatter.parse(sj2);
		day = (date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000);
	} catch (Exception e) {
		return "";
	}
	return day + "";
}
/**
* 根据一个日期，返回是星期几的字符串
*/
public static String getWeek(String sdate) {
	// 再转换为时间
	Date date = TimeTest.strToDate(sdate);
	Calendar c = Calendar.getInstance();
	c.setTime(date);
	// int hour=c.get(Calendar.DAY_OF_WEEK);
	// hour 中存的就是星期几了，其范围 1~7
	// 1=星期日 7=星期六，其他类推
	return new SimpleDateFormat("EEEE").format(c.getTime());
}
/**
* 将短时间格式字符串转换为时间 yyyy-MM-dd
*/
public static Date strToDate(String strDate) {
	SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
	ParsePosition pos = new ParsePosition(0);
	Date strtodate = formatter.parse(strDate, pos);
	return strtodate;
}
/**
* 两个时间之间的天数
*
* @param date1
* @param date2
* @return
*/
public static long getDays(String date1, String date2) {
	if (date1 == null || date1.equals(""))return 0;
	if (date2 == null || date2.equals(""))return 0;
	// 转换为标准时间
	SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");
	java.util.Date date = null;
	java.util.Date mydate = null;
	try {
		date = myFormatter.parse(date1);
		mydate = myFormatter.parse(date2);
	} catch (Exception e) {
	}
	long day = (date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000);
	return day;
}
// 计算当月最后一天,返回字符串
public String getDefaultDay(){
	String str = "";
	SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
	Calendar lastDate = Calendar.getInstance();
	lastDate.set(Calendar.DATE,1);//设为当前月的1 号
	lastDate.add(Calendar.MONTH,1);//加一个月，变为下月的1 号
	lastDate.add(Calendar.DATE,-1);//减去一天，变为当月最后一天
	str=sdf.format(lastDate.getTime());
	return str;
}
// 上月第一天
public String getPreviousMonthFirst(){
	String str = "";
	SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
	Calendar lastDate = Calendar.getInstance();
	lastDate.set(Calendar.DATE,1);//设为当前月的1 号
	lastDate.add(Calendar.MONTH,-1);//减一个月，变为下月的1 号
	//lastDate.add(Calendar.DATE,-1);//减去一天，变为当月最后一天
	str=sdf.format(lastDate.getTime());
	return str;
}
//获取当月第一天
public String getFirstDayOfMonth(){
	String str = "";
	SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
	Calendar lastDate = Calendar.getInstance();
	lastDate.set(Calendar.DATE,1);//设为当前月的1 号
	str=sdf.format(lastDate.getTime());
	return str;
}
// 获得本周星期日的日期
public String getCurrentWeekday() {
	weeks = 0;
	int mondayPlus = this.getMondayPlus();
	GregorianCalendar currentDate = new GregorianCalendar();
	currentDate.add(GregorianCalendar.DATE, mondayPlus+6);
	Date monday = currentDate.getTime();
	DateFormat df = DateFormat.getDateInstance();
	String preMonday = df.format(monday);
	return preMonday;
}
//获取当天时间
public String getNowTime(String dateformat){
	Date now = new Date();
	SimpleDateFormat dateFormat = new SimpleDateFormat(dateformat);//可以方便地修改日期格式
	String hehe = dateFormat.format(now);
	return hehe;
}
// 获得当前日期与本周日相差的天数
private int getMondayPlus() {
	Calendar cd = Calendar.getInstance();
	// 获得今天是一周的第几天，星期日是第一天，星期二是第二天......
	int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK)-1; //因为按中国礼拜一作为第一天所以这里减1
	if (dayOfWeek == 1) {
		return 0;
	} else {
		return 1 - dayOfWeek;
	}
}
//获得本周一的日期
public String getMondayOFWeek(){
	weeks = 0;
	int mondayPlus = this.getMondayPlus();
	GregorianCalendar currentDate = new GregorianCalendar();
	currentDate.add(GregorianCalendar.DATE, mondayPlus);
	Date monday = currentDate.getTime();
	DateFormat df = DateFormat.getDateInstance();
	String preMonday = df.format(monday);
	return preMonday;
}
//获得相应周的周六的日期
public String getSaturday() {
	int mondayPlus = this.getMondayPlus();
	GregorianCalendar currentDate = new GregorianCalendar();
	currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 * weeks + 6);
	Date monday = currentDate.getTime();
	DateFormat df = DateFormat.getDateInstance();
	String preMonday = df.format(monday);
	return preMonday;
}
// 获得上周星期日的日期
public String getPreviousWeekSunday() {
	weeks=0;
	weeks--;
	int mondayPlus = this.getMondayPlus();
	GregorianCalendar currentDate = new GregorianCalendar();
	currentDate.add(GregorianCalendar.DATE, mondayPlus+weeks);
	Date monday = currentDate.getTime();
	DateFormat df = DateFormat.getDateInstance();
	String preMonday = df.format(monday);
	return preMonday;
}
// 获得上周星期一的日期
public String getPreviousWeekday() {
	weeks--;
	int mondayPlus = this.getMondayPlus();
	GregorianCalendar currentDate = new GregorianCalendar();
	currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 * weeks);
	Date monday = currentDate.getTime();
	DateFormat df = DateFormat.getDateInstance();
	String preMonday = df.format(monday);
	return preMonday;
}
// 获得下周星期一的日期
public String getNextMonday() {
	weeks++;
	int mondayPlus = this.getMondayPlus();
	GregorianCalendar currentDate = new GregorianCalendar();
	currentDate.add(GregorianCalendar.DATE, mondayPlus + 7);
	Date monday = currentDate.getTime();
	DateFormat df = DateFormat.getDateInstance();
	String preMonday = df.format(monday);
	return preMonday;
}
// 获得下周星期日的日期
public String getNextSunday() {
	int mondayPlus = this.getMondayPlus();
	GregorianCalendar currentDate = new GregorianCalendar();
	currentDate.add(GregorianCalendar.DATE, mondayPlus + 7+6);
	Date monday = currentDate.getTime();
	DateFormat df = DateFormat.getDateInstance();
	String preMonday = df.format(monday);
	return preMonday;
}
private int getMonthPlus(){
	Calendar cd = Calendar.getInstance();
	int monthOfNumber = cd.get(Calendar.DAY_OF_MONTH);
	cd.set(Calendar.DATE, 1);//把日期设置为当月第一天
	cd.roll(Calendar.DATE, -1);//日期回滚一天，也就是最后一天
	MaxDate=cd.get(Calendar.DATE);
	if(monthOfNumber == 1){
	return -MaxDate;
	}else{
	return 1-monthOfNumber;
	}
}
//获得上月最后一天的日期
public String getPreviousMonthEnd(){
	String str = "";
	SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
	Calendar lastDate = Calendar.getInstance();
	lastDate.add(Calendar.MONTH,-1);//减一个月
	lastDate.set(Calendar.DATE, 1);//把日期设置为当月第一天
	lastDate.roll(Calendar.DATE, -1);//日期回滚一天，也就是本月最后一天
	str=sdf.format(lastDate.getTime());
	return str;
}
//获得下个月第一天的日期
public String getNextMonthFirst(){
String str = "";
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
Calendar lastDate = Calendar.getInstance();
lastDate.add(Calendar.MONTH,1);//减一个月
lastDate.set(Calendar.DATE, 1);//把日期设置为当月第一天
str=sdf.format(lastDate.getTime());
return str;
}
//获得下个月最后一天的日期
public String getNextMonthEnd(){
	String str = "";
	SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
	Calendar lastDate = Calendar.getInstance();
	lastDate.add(Calendar.MONTH,1);//加一个月
	lastDate.set(Calendar.DATE, 1);//把日期设置为当月第一天
	lastDate.roll(Calendar.DATE, -1);//日期回滚一天，也就是本月最后一天
	str=sdf.format(lastDate.getTime());
	return str;
}
//获得明年最后一天的日期
public String getNextYearEnd(){
	String str = "";
	SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
	Calendar lastDate = Calendar.getInstance();
	lastDate.add(Calendar.YEAR,1);//加一个年
	lastDate.set(Calendar.DAY_OF_YEAR, 1);
	lastDate.roll(Calendar.DAY_OF_YEAR, -1);
	str=sdf.format(lastDate.getTime());
	return str;
}
//获得明年第一天的日期
public String getNextYearFirst(){
	String str = "";
	SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
	Calendar lastDate = Calendar.getInstance();
	lastDate.add(Calendar.YEAR,1);//加一个年
	lastDate.set(Calendar.DAY_OF_YEAR, 1);
	str=sdf.format(lastDate.getTime());
	return str;
}
//获得本年有多少天
private int getMaxYear(){
	Calendar cd = Calendar.getInstance();
	cd.set(Calendar.DAY_OF_YEAR,1);//把日期设为当年第一天
	cd.roll(Calendar.DAY_OF_YEAR,-1);//把日期回滚一天。
	int MaxYear = cd.get(Calendar.DAY_OF_YEAR);
	return MaxYear;
}
private int getYearPlus(){
	Calendar cd = Calendar.getInstance();
	int yearOfNumber = cd.get(Calendar.DAY_OF_YEAR);//获得当天是一年中的第几天
	cd.set(Calendar.DAY_OF_YEAR,1);//把日期设为当年第一天
	cd.roll(Calendar.DAY_OF_YEAR,-1);//把日期回滚一天。
	int MaxYear = cd.get(Calendar.DAY_OF_YEAR);
	if(yearOfNumber == 1){
		return -MaxYear;
	}else{
		return 1-yearOfNumber;
	}
}
//获得本年第一天的日期
public String getCurrentYearFirst(){
	int yearPlus = this.getYearPlus();
	GregorianCalendar currentDate = new GregorianCalendar();
	currentDate.add(GregorianCalendar.DATE,yearPlus);
	Date yearDay = currentDate.getTime();
	DateFormat df = DateFormat.getDateInstance();
	String preYearDay = df.format(yearDay);
	return preYearDay;
}
//获得本年最后一天的日期 *
public String getCurrentYearEnd(){
	Date date = new Date();
	SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");//可以方便地修改日期格式
	String years = dateFormat.format(date);
	return years+"-12-31";
}
//获得上年第一天的日期 *
public String getPreviousYearFirst(){
	Date date = new Date();
	SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");//可以方便地修改日期格式
	String years = dateFormat.format(date); int years_value = Integer.parseInt(years);
	years_value--;
	return years_value+"-1-1";
}
//获得上年最后一天的日期
public String getPreviousYearEnd(){
	weeks--;
	int yearPlus = this.getYearPlus();
	GregorianCalendar currentDate = new GregorianCalendar();
	currentDate.add(GregorianCalendar.DATE,yearPlus+MaxYear*weeks+(MaxYear-1));
	Date yearDay = currentDate.getTime();
	DateFormat df = DateFormat.getDateInstance();
	String preYearDay = df.format(yearDay);
	getThisSeasonTime(11);
	return preYearDay;
}
/**
* 获取某年某月的最后一天
* @param year 年
* @param month 月
* @return 最后一天
*/
private int getLastDayOfMonth(int year, int month) {
	if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8
	|| month == 10 || month == 12) {
		return 31;
	}
	if (month == 4 || month == 6 || month == 9 || month == 11) {
		return 30;
	}
	if (month == 2) {
		if (isLeapYear(year)) {
			return 29;
		} else {
			return 28;
		}
	}
	return 0;
}
/**
* 是否闰年
* @param year 年
* @return
*/
public boolean isLeapYear(int year) {
	return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);
}
}