1 package com.example.alimjan.hello_world;  2   3 /**  4  * Created by alimjan on 6/30/2017.  5  */  6   7         import java.text.ParseException;  8         import java.text.SimpleDateFormat;  9         import java.util.Calendar; 10         import java.util.Date; 11  12  13 public class DateUtil { 14  15     private static final String FORMAT = "yyyy-MM-dd HH:mm:ss"; 16  17     public static Date str2Date(String str) { 18         return str2Date(str, null); 19     } 20  21     public static Date str2Date(String str, String format) { 22         if (str == null || str.length() == 0) { 23             return null; 24         } 25         if (format == null || format.length() == 0) { 26             format = FORMAT; 27         } 28         Date date = null; 29         try { 30             SimpleDateFormat sdf = new SimpleDateFormat(format); 31             date = sdf.parse(str); 32  33         } catch (Exception e) { 34             e.printStackTrace(); 35         } 36         return date; 37  38     } 39  40     public static Calendar str2Calendar(String str) { 41         return str2Calendar(str, null); 42  43     } 44  45     public static Calendar str2Calendar(String str, String format) { 46  47         Date date = str2Date(str, format); 48         if (date == null) { 49             return null; 50         } 51         Calendar c = Calendar.getInstance(); 52         c.setTime(date); 53  54         return c; 55  56     } 57  58     public static String date2Str(Calendar c) {
   // yyyy-MM-dd HH:mm:ss 59         return date2Str(c, null); 60     } 61  62     public static String date2Str(Calendar c, String format) { 63         if (c == null) { 64             return null; 65         } 66         return date2Str(c.getTime(), format); 67     } 68  69     public static String date2Str(Date d) {
   // yyyy-MM-dd HH:mm:ss 70         return date2Str(d, null); 71     } 72  73     public static String date2Str(Date d, String format) {
   // yyyy-MM-dd HH:mm:ss 74         if (d == null) { 75             return null; 76         } 77         if (format == null || format.length() == 0) { 78             format = FORMAT; 79         } 80         SimpleDateFormat sdf = new SimpleDateFormat(format); 81         String s = sdf.format(d); 82         return s; 83     } 84  85     public static String getCurDateStr() { 86         Calendar c = Calendar.getInstance(); 87         c.setTime(new Date()); 88         return c.get(Calendar.YEAR) + "-" + (c.get(Calendar.MONTH) + 1) + "-" 89                 + c.get(Calendar.DAY_OF_MONTH) + "-" 90                 + c.get(Calendar.HOUR_OF_DAY) + ":" + c.get(Calendar.MINUTE) 91                 + ":" + c.get(Calendar.SECOND); 92     } 93  94     /** 95      * 获得当前日期的字符串格式 96      * 97      * @param format 98      * @return 99      */100     public static String getCurDateStr(String format) {101         Calendar c = Calendar.getInstance();102         return date2Str(c, format);103     }104 105     // 格式到秒106     public static String getMillon(long time) {107 108         return new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss").format(time);109 110     }111 112     // 格式到天113     public static String getDay(long time) {114 115         return new SimpleDateFormat("yyyy-MM-dd").format(time);116 117     }118 119     // 格式到毫秒120     public static String getSMillon(long time) {121 122         return new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss-SSS").format(time);123 124     }125 126 127     /*128      输入的是String，格式诸如20120102，实现加一天的功能，返回的格式为String，诸如20120103129      */130     public static String stringDatePlus(String row) throws ParseException{131         String year=row.substring(0, 4);132         String month=row.substring(4,6);133         String day=row.substring(6);134         String date1=year+"-"+month+"-"+day;135         SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");136         Date startDate=sdf.parse(date1);137         Calendar cd = Calendar.getInstance();138         cd.setTime(startDate);139         cd.add(Calendar.DATE, 1);140         String dateStr =sdf.format(cd.getTime());141         String year1=dateStr.substring(0,4);142         String month1=dateStr.substring(5,7);143         String day1=dateStr.substring(8);144         return year1+month1+day1;145     }146 147     /*148      输入的是String，格式诸如20120102，实现减一天的功能，返回的格式为String，诸如20120101149      */150     public static String stringDateDecrease(String row) throws ParseException{151         String year=row.substring(0, 4);152         String month=row.substring(4,6);153         String day=row.substring(6);154         String date1=year+"-"+month+"-"+day;155         SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");156         Date startDate=sdf.parse(date1);157         Calendar cd = Calendar.getInstance();158         cd.setTime(startDate);159         cd.add(Calendar.DATE, -1);160         String dateStr =sdf.format(cd.getTime());161         String year1=dateStr.substring(0,4);162         String month1=dateStr.substring(5,7);163         String day1=dateStr.substring(8);164         return year1+month1+day1;165     }166 167     /*168      输入的格式为String，诸如20120101，返回的格式为String，诸如2012-01-01169      */170     public static String stringDateChange(String date)171     {172         if(date.length()=="20120101".length()){173             String year=date.substring(0, 4);174             String month=date.substring(4,6);175             String day=date.substring(6);176             return year+"-"+month+"-"+day;177         }else{178             return date;179         }180 181 182     }183     /**184      * 日期向后推一天185      * @param date 格式：20120101186      * @return  20120102187      */188     public static String tonextday(String date){189         int year = Integer.parseInt(date.substring(0,4));190         int month = Integer.parseInt(date.substring(4,6));191         int day = Integer.parseInt(date.substring(6));192         Calendar calendar = Calendar.getInstance();193         calendar.set(year, month-1, day+1);194         Date newdate = calendar.getTime();195         SimpleDateFormat format = new SimpleDateFormat("yyyyMMdd");196         String da = format.format(newdate);197         return da;198     }199 200     /**201      * 获取当前日期上一周的开始日期 （周日）202      */203     public static String previousWeekByDate(String date) {204         int year = Integer.parseInt(date.substring(0,4));205         int month = Integer.parseInt(date.substring(4,6));206         int day = Integer.parseInt(date.substring(6));207         Calendar calendar = Calendar.getInstance();208         calendar.set(year, month-1, day);209         Date newdate = calendar.getTime();210         SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");211         Calendar cal = Calendar.getInstance();212         cal.setTime(newdate);213         int dayWeek = cal.get(Calendar.DAY_OF_WEEK);//获得当前日期是一个星期的第几天214         if(1 == dayWeek) {215             cal.add(Calendar.DAY_OF_MONTH, -1);216         }217         cal.setFirstDayOfWeek(Calendar.SUNDAY);//设置一个星期的第一天，按中国的习惯一个星期的第一天是星期一218         int s = cal.get(Calendar.DAY_OF_WEEK);//获得当前日期是一个星期的第几天219         cal.add(Calendar.DATE, cal.getFirstDayOfWeek()-s);//根据日历的规则，给当前日期减往星期几与一个星期第一天的差值220         cal.add(Calendar.WEEK_OF_YEAR, -1);221         String imptimeBegin = sdf.format(cal.getTime());222 //      System.out.println("所在周星期日的日期："+imptimeBegin);223         return imptimeBegin;224     }225 226 227     /**228      * 获取当前日期上一周的结束日期 （周六）229      */230     public static String previousWeekEndDayByDate(String date) {231         int year = Integer.parseInt(date.substring(0,4));232         int month = Integer.parseInt(date.substring(4,6));233         int day = Integer.parseInt(date.substring(6));234         Calendar calendar = Calendar.getInstance();235         calendar.set(year, month-1, day);236         Date newdate = calendar.getTime();237         SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");238         Calendar cal = Calendar.getInstance();239         cal.setTime(newdate);240         int dayWeek = cal.get(Calendar.DAY_OF_WEEK);//获得当前日期是一个星期的第几天241         if(1 == dayWeek) {242             cal.add(Calendar.DAY_OF_MONTH, -1);243         }244         cal.setFirstDayOfWeek(Calendar.SUNDAY);//设置一个星期的第一天，按中国的习惯一个星期的第一天是星期一245         int s = cal.get(Calendar.DAY_OF_WEEK);//获得当前日期是一个星期的第几天246         cal.add(Calendar.DATE, cal.getFirstDayOfWeek()+(6-s));247         cal.add(Calendar.WEEK_OF_YEAR, -1);248         String imptimeBegin = sdf.format(cal.getTime());249 //      System.out.println("星期六的日期："+imptimeBegin);250         return imptimeBegin;251     }252 253 254     /**255      * 获取当前日期当前一周的开始日期 （周日）256      */257     public static String getCurrentWeekFirstDayByDate(String date) {258         int year = Integer.parseInt(date.substring(0,4));259         int month = Integer.parseInt(date.substring(4,6));260         int day = Integer.parseInt(date.substring(6));261         Calendar calendar = Calendar.getInstance();262         calendar.set(year, month-1, day);263         Date newdate = calendar.getTime();264         SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");265         Calendar cal = Calendar.getInstance();266         cal.setTime(newdate);267         int dayWeek = cal.get(Calendar.DAY_OF_WEEK);//获得当前日期是一个星期的第几天268         if(1 == dayWeek) {269             cal.add(Calendar.DAY_OF_MONTH, -1);270         }271         cal.setFirstDayOfWeek(Calendar.SUNDAY);//设置一个星期的第一天，按中国的习惯一个星期的第一天是星期一272         int s = cal.get(Calendar.DAY_OF_WEEK);//获得当前日期是一个星期的第几天273         cal.add(Calendar.DATE, cal.getFirstDayOfWeek()-s);//根据日历的规则，给当前日期减往星期几与一个星期第一天的差值274 275         String imptimeBegin = sdf.format(cal.getTime());276         //  System.out.println("所在周星期日的日期："+imptimeBegin);277         return imptimeBegin;278     }279     /**280      * 获取当前日期当前一周的结束日期 （周六）281      */282     public static String getCurrentWeekEndDayByDate(String date) {283         int year = Integer.parseInt(date.substring(0,4));284         int month = Integer.parseInt(date.substring(4,6));285         int day = Integer.parseInt(date.substring(6));286         Calendar calendar = Calendar.getInstance();287         calendar.set(year, month-1, day);288         Date newdate = calendar.getTime();289         SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");290         Calendar cal = Calendar.getInstance();291         cal.setTime(newdate);292         int dayWeek = cal.get(Calendar.DAY_OF_WEEK);//获得当前日期是一个星期的第几天293         if(1 == dayWeek) {294             cal.add(Calendar.DAY_OF_MONTH, -1);295         }296         cal.setFirstDayOfWeek(Calendar.SUNDAY);//设置一个星期的第一天，按中国的习惯一个星期的第一天是星期一297         int s = cal.get(Calendar.DAY_OF_WEEK);//获得当前日期是一个星期的第几天298         cal.add(Calendar.DATE, cal.getFirstDayOfWeek()+(6-s));299 300         String imptimeBegin = sdf.format(cal.getTime());301         return imptimeBegin;302     }303 304 305     /**306      * 返回上一个月的第一天307      * @param date20120304308      * @return  20120201309      */310     public static String previousMonthByDate(String date) {311         // TODO Auto-generated method stub312         int year = Integer.parseInt(date.substring(0,4));313         int month = Integer.parseInt(date.substring(4,6));314         int day = Integer.parseInt(date.substring(6));315         Calendar calendar = Calendar.getInstance();316         calendar.set(year, month-2, 1);317         Date newdate = calendar.getTime();318         SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");319         Calendar cal = Calendar.getInstance();320         cal.setTime(newdate);321         String imptimeBegin = sdf.format(cal.getTime());322 //      System.out.println(imptimeBegin);323         return imptimeBegin;324     }325 326     /**327      * 返回下一个月的第一天328      * @param date20120304329      * @return  20120401330      */331     public static String nextMonthByDate(String date) {332         // TODO Auto-generated method stub333         int year = Integer.parseInt(date.substring(0,4));334         int month = Integer.parseInt(date.substring(4,6));335         int day = Integer.parseInt(date.substring(6));336         Calendar calendar = Calendar.getInstance();337         calendar.set(year, month, 1);338         Date newdate = calendar.getTime();339         SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");340         Calendar cal = Calendar.getInstance();341         cal.setTime(newdate);342         String imptimeBegin = sdf.format(cal.getTime());343 //      System.out.println(imptimeBegin);344         return imptimeBegin;345     }346     /**347      * 返回当前月的第一天348      * @param date20120103349      * @return 20120101350      */351     public static String getCurrentMonthFirstDayByDate(String date) {352         int year = Integer.parseInt(date.substring(0,4));353         int month = Integer.parseInt(date.substring(4,6));354         int day = Integer.parseInt(date.substring(6));355         Calendar calendar = Calendar.getInstance();356         calendar.set(year, month-1, 1);357         Date newdate = calendar.getTime();358         SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");359         Calendar cal = Calendar.getInstance();360         cal.setTime(newdate);361         String imptimeBegin = sdf.format(cal.getTime());362         return imptimeBegin;363     }364 365 }