这篇文章主要介绍了java实现的日期处理类,结合完整实例形式分析了java针对日期的获取、运算、转换等相关操作技巧,需要的朋友可以参考下
本文实例讲述了Java实现的日期处理类。分享给大家供大家参考，具体如下：
开发中常常要使用日期，先小结如下，以备后用。
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class FormatTime {
private final static SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");
private final static SimpleDateFormat sdfymdhm = new SimpleDateFormat("yyyyMMddHHmmss");
private final static SimpleDateFormat sdfymdhms = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
/**
*
* @Title: getCurrentDay
* @Description: TODO 获取当天时间(20161109)
* @return
*/
public static String getCurrentDay(){
return sdf.format(new Date());
}
/**
*
* @Title: fTime2
* @Description: TODO 获取time这个日期以前dayAgo天的日期
* @return
*/
public static String fTime(String time,int dayAgo){
Date date = null;
try {
date = sdf.parse(time);
} catch (ParseException e) {
throw new RuntimeException(e);
}
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
if(dayAgo>0){
calendar.add(Calendar.DAY_OF_MONTH, -dayAgo);//前15天数据
date = calendar.getTime();
calendar.setTime(date);
}
int year=calendar.get(Calendar.YEAR);
int month=calendar.get(Calendar.MONTH) + 1;
int day = calendar.get(Calendar.DAY_OF_MONTH);
String mon="";
String d="";
if(month<10){
mon="0"+month;
}else{
mon=month+"";
}
if(day<10){
d="0"+day;
}else{
d=""+day;
}
String ret=year+""+mon+""+d;
return ret;
}
/**
*
* @Title: fTime2
* @Description: TODO 获取time这个日期以后dayAfter天的日期
* @return
*/
public static String fTime2(String time,int dayAfter){
Date date = null;
try {
date = sdf.parse(time);
} catch (ParseException e) {
throw new RuntimeException(e);
}
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
if(dayAfter>0){
calendar.add(Calendar.DAY_OF_MONTH, +dayAfter);//后15天数据
date = calendar.getTime();
calendar.setTime(date);
}
int year=calendar.get(Calendar.YEAR);
int month=calendar.get(Calendar.MONTH) + 1;
int day = calendar.get(Calendar.DAY_OF_MONTH);
String mon="";
String d="";
if(month<10){
mon="0"+month;
}else{
mon=month+"";
}
if(day<10){
d="0"+day;
}else{
d=""+day;
}
String ret=year+""+mon+""+d;
return ret;
}
/**
*
* @Title: getDefaultTime
* @Description: TODO 获取昨天的日期
* @return
*/
public static String getDefaultTime(){
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.DAY_OF_MONTH, -1);//前1天
Date date = calendar.getTime();
String time=sdf.format(date);
return time;
}
/**
*
* @Title: getSunday
* @Description: TODO 获取最近一个星期天
* @return
*/
public static String getSunday(){
SimpleDateFormat f = new SimpleDateFormat("yyyyMMdd");
Calendar c = Calendar.getInstance();
c.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
return f.format(c.getTime());
}
/**
*
* @Title: getMonthFirstDay
* @Description: TODO 获取本月第一天
* @return
*/
public static String getCurrentMonthFirstDay(){
Calendar cal_1=Calendar.getInstance();//获取当前日期
cal_1.add(Calendar.MONTH, 0);
cal_1.set(Calendar.DAY_OF_MONTH,1);//设置为1号,当前日期既为本月第一天
String firstDay = sdf.format(cal_1.getTime());
return firstDay;
}
/**
*
* @Title: getMonthFirstDay
* @Description: TODO 获取上月第一天
* @return
*/
public static String getPreviousMonthFirstDay(){
//获取当前月第一天：
Calendar c = Calendar.getInstance();
c.add(Calendar.MONTH, -1);
c.set(Calendar.DAY_OF_MONTH,1);//设置为1号,当前日期既为本月第一天
String first = sdf.format(c.getTime());
return first;
}
/**
*
* @Title: getMonthFirstDay
* @Description: TODO 获取上月最后一天
* @return
*/
public static String getPreviousMonthLastDay(){
//获取当前月最后一天
Calendar ca = Calendar.getInstance();
ca.set(Calendar.DAY_OF_MONTH,0);//
String lastDay = sdf.format(ca.getTime());
return lastDay;
}
/**
*
* @Title: getCurrentMonthLastDay
* @Description: TODO 获取指定时间最后一天
* @return
*/
public static String getCurrentMonthLastDay(String time){
Date date =null;
try {
date= sdf.parse(time);
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//获取当前月最后一天
Calendar ca = Calendar.getInstance();
ca.setTime(date);
ca.set(Calendar.DAY_OF_MONTH,
ca.getActualMaximum(Calendar.DAY_OF_MONTH)); //
String lastDay = sdf.format(ca.getTime());
return lastDay;
}
/***
*
* @Title: getCurrentWeekDay
* @Description: TODO 获取本周周一
*/
public static String getCurrentMonday(){
Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);//将每周第一天设为星期一，默认是星期天
cal.add(Calendar.DATE, 0);
cal.set(Calendar.DAY_OF_WEEK,Calendar.MONDAY);
String monday = sdf.format(cal.getTime());
return monday;
}
/***
*
* @Title: getPreviousSunday
* @Description: TODO 获取上周周日
*/
public static String getPreviousSunday(){
Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);//将每周第一天设为星期一，默认是星期天
cal.add(Calendar.DATE, -1*7);
cal.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
String sunday =sdf.format(cal.getTime());
return sunday;
}
/**
*
* @Title: getMiniSencond
* @Description: TODO 将日期转换为毫秒数
* @param str
* @return
*/
public static String getMiniSencond(String str){
long millionSeconds=0;
try {
millionSeconds = sdfymdhm.parse(str).getTime();//毫秒
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return millionSeconds+"";
}
/**
*
* @Title: getDateSencond
* @Description: TODO 将日期转换为毫秒数
* @param str
* @return
*/
public static long getDateSencond(String str){
long millionSeconds=0;
try {
millionSeconds = sdfymdhms.parse(str).getTime();//毫秒
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return millionSeconds;
}
/**
* 计算日期相差天数
* @param str1
* @param str2
* @return
*/
public static int getDistanceOfTwoDate(String str1,String str2){
int result=0;
try{
Date date1 = sdf.parse(str1);
Date date2 =sdf.parse(str2);
Calendar aCalendar = Calendar.getInstance();
aCalendar.setTime(date1);
int day1 = aCalendar.get(Calendar.DAY_OF_YEAR);
aCalendar.setTime(date2);
int day2 = aCalendar.get(Calendar.DAY_OF_YEAR);
result = day1-day2;
}catch(Exception e){
e.printStackTrace();
}
return result;
}
/**
*
* @Title: long2Date
* @Description: TODO long 转日期(年-月-日 时-分-秒)
* @param timestamp
* @return
*/
public static String longToDate(Long msecond){
Date date = new Date(msecond);
return sdfymdhms.format(date);
}
} 
