Java日期获取需求大全

刚进公司，作为熟悉技术，为公司做了一个小的点餐系统的网站，其中大量用到了时间日期作为唯一标示或是显示设置。特总结了一下和大家分享。

package com.lucis.ordering.Utils;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

/**
 * Created by JayZhao on 2015/8/17 0017.
 *  系统日期获取控件
 */
public class DateUtil {

    //实例化date对象
    Date date = new Date();
    //格式化成年月日式 date 类型
    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
    //格式化年月日 时分秒  date 类型
    SimpleDateFormat detailsDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    //解析成年-月-日 格式date形数据
    public Date SimpleSystemTime(){
        String now =new SimpleDateFormat("yyyy-MM-dd").format(date);
        try {
            return simpleDateFormat.parse(now);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;
    }
    //解析成年-月-日 格式String形数据
    public String SimpleSystemTimeString(){
        return new SimpleDateFormat("yyyy-MM-dd").format(date);
    }
    //解析成年-月-日 时：分：秒 格式date形数据
    public Date DetailSystemTime(){
        String now =new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(date);
        try {
            return detailsDateFormat.parse(now);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;
    }
    //解析成年-月-日 星期几 格式date形数据
    public  String  MiddleSystemTime() {
        String now =new SimpleDateFormat("yyyy-MM-dd").format(date);
        String[] weekDays = {"星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"};
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int w = cal.get(Calendar.DAY_OF_WEEK) - 1;
        if (w < 0) {
            w = 0;
        }
        return now+" "+weekDays[w];
    }
    //根据时间获取当日星期
    public int WeekDays(String day){

        Calendar cal = Calendar.getInstance();
        try {
            cal.setTime(simpleDateFormat.parse(day));
        } catch (ParseException e) {
            e.printStackTrace();
        }
        int w = cal.get(Calendar.DAY_OF_WEEK) - 1;
        return w;
    }
    //解析当前日期前几天成 年-月-日 格式的date数据
    public String Yesterday(){
        Calendar calendar = Calendar.getInstance();//此时打印它获取的是系统当前时间
        calendar.add(Calendar.DATE, -1);    //得到前一天
        return new SimpleDateFormat("yyyy-MM-dd").format(calendar.getTime());
    }
    //解析某一天的前几天
    public String getSpecifiedDayBefore(String specifiedDay,int d){
        Calendar c = Calendar.getInstance();
        Date date=null;
        try {
            date = new SimpleDateFormat("yy-MM-dd").parse(specifiedDay);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        c.setTime(date);
        int day=c.get(Calendar.DATE);
        c.set(Calendar.DATE,day-d);
        String dayBefore=new SimpleDateFormat("yyyy-MM-dd").format(c.getTime());
        return dayBefore;
    }
    //比较两个时间大小
    public boolean compare(String date1,String date2){
        boolean result = false;
        try {
             result = simpleDateFormat.parse(date1).before(simpleDateFormat.parse(date2));
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return result;
    }
    //根据一天获取一周时间
    public String testDate(String newtime) {
        String dayNames[] = {"星期日","星期一","星期二","星期三","星期四","星期五","星期六"};
        int week1[] = {7,1,2,3,4,5,6};
        Calendar c = Calendar.getInstance();// 获得一个日历的实例
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        try {
            c.setTime(sdf.parse(newtime));
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        String a=dayNames[c.get(Calendar.DAY_OF_WEEK)-1];
        int b=week1[c.get(Calendar.DAY_OF_WEEK)-1];
        if(b!=7){
            c.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
        }else{
            c.add(Calendar.WEEK_OF_MONTH, -1);
            c.set(Calendar.DAY_OF_WEEK, 2);
        }
        return a;
    }

    //获取某一天的下周一
    public String getNextMonday(Date date){
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int week = cal.get(Calendar.DAY_OF_WEEK);
        if(week>2){
            cal.add(Calendar.DAY_OF_MONTH,-(week-2)+7);
        }else{
            cal.add(Calendar.DAY_OF_MONTH,2-week+7);
        }
        return new SimpleDateFormat("yyyy-MM-dd").format(cal.getTime());
    }

    //获取某一天的本周一
    public String getMonday(Date date){
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int week = cal.get(Calendar.DAY_OF_WEEK);
        if(week>2){
            cal.add(Calendar.DAY_OF_MONTH,-(week-2));
        }else{
            cal.add(Calendar.DAY_OF_MONTH,2-week);
        }
        return new SimpleDateFormat("yyyy-MM-dd").format(cal.getTime());
    }
}