java 获取系统当前时间

Calendar date = CalendargetInstance();

int day = dateget(CalendarDAY_OF_MONTH);

int month = dateget(CalendarMONTH) + 1;

int year = dateget(CalendarYEAR);

Systemoutprintln("day=" + day);

Systemoutprintln("month=" + month);

Systemoutprintln("year=" + year);

如果再不对的话，看一下你系统的时间对不对。

import javatextDateFormatSymbols;

import javautilCalendar;

import javautilGregorianCalendar;

public class Test {

/

@param args

/

public static void main(String[] args){

Calendar c_begin = new GregorianCalendar();

Calendar c_end = new GregorianCalendar();

DateFormatSymbols dfs = new DateFormatSymbols();

String[] weeks = dfsgetWeekdays();

c_beginset(2010, 3, 2); //Calendar的月从0-11，所以4月是3

c_endset(2010, 4, 20); //Calendar的月从0-11，所以5月是4

int count = 1;

c_endadd(CalendarDAY_OF_YEAR, 1); //结束日期下滚一天是为了包含最后一天

while(c_beginbefore(c_end)){

Systemoutprintln("第"+count+"周 日期："+new javasqlDate(c_begingetTime()getTime())+", "+weeks[c_beginget(CalendarDAY_OF_WEEK)]);

if(c_beginget(CalendarDAY_OF_WEEK)==CalendarSUNDAY){

count++;

}

c_beginadd(CalendarDAY_OF_YEAR, 1);

}

}

}

import javautilCalendar;

import javautilDate;

public class TestDate

{

public static void main(String[] args)

{

// TODO Auto-generated method stub

Calendar cal=CalendargetInstance();

calsetTime(new Date());

int i = calget(CalendarWEEK_OF_YEAR);

Systemoutprintln(i);

}

}

一 获取当前系统时间和日期并格式化输出:

import javautilDate;

import javatextSimpleDateFormat;

public class NowString {

public static void main(String[] args) {

SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式

Systemoutprintln(dfformat(new Date()));// new Date()为获取当前系统时间

}

}

二 在数据库里的日期只以年-月-日的方式输出，可以用下面两种方法：

1、用convert()转化函数：

String sqlst = "select convert(varchar(10),bookDate,126) as convertBookDate from roomBook where bookDate between '2007-4-10' and '2007-4-25'";

Systemoutprintln(rsgetString("convertBookDate"));

2、利用SimpleDateFormat类：

先要输入两个java包：

import javautilDate;

import javatextSimpleDateFormat;

然后：

定义日期格式：SimpleDateFormat sdf = new SimpleDateFormat(yy-MM-dd);

sql语句为：String sqlStr = "select bookDate from roomBook where bookDate between '2007-4-10' and '2007-4-25'";

输出：

Systemoutprintln(dfformat(rsgetDate("bookDate")));

获取本周一

 public static Date getNowWeekMonday(Date date) {    

            Calendar cal = CalendargetInstance();    

             calsetTime(date);    

                  

             caladd(CalendarDAY_OF_MONTH, -1); //解决周日会出现 并到下一周的情况    

            calset(CalendarDAY_OF_WEEK, CalendarMONDAY);    

                 

303            return calgetTime();    

        }

获取上周一

public static Date getLastWeekMonday(Date date) {    

             Date a = DateUtilsaddDays(date, -1);    

            Calendar cal = CalendargetInstance();    

            calsetTime(a);    

            caladd(CalendarWEEK_OF_YEAR, -1);// 一周    

            calset(CalendarDAY_OF_WEEK, CalendarMONDAY);    

                  

             return calgetTime();    

        }

获取上周日

public static Date  getLastWeekSunday(Date date) {    

                 

            Date a = DateUtilsaddDays(date, -1);    

           Calendar cal = CalendargetInstance();    

         calsetTime(a);    

           calset(CalendarDAY_OF_WEEK, 1);    

                 

          return calgetTime();    

        }

代码里面有用到 lapachecommon-ang包 你需要下载下 就可以使用

Calendar c_begin = CalendargetInstance();

Calendar c_end = CalendargetInstance();

c_beginset(2010, 3, 1); //Calendar的月从0-11，所以4月是3

c_endset(2010, 4, 20); //Calendar的月从0-11，所以5月是4

int count = 0;

while(c_beginbefore(c_end)){

//Systemoutprintln(new javasqlDate(c_begingetTime()getTime()));

if(c_beginget(CalendarDAY_OF_WEEK)==CalendarMONDAY){

count++;

}

if(count == 2){

Systemoutprintln(c_beginget(CalendarYEAR)+"年"+(c_beginget(CalendarMONTH)+1)+"月"+c_beginget(CalendarDATE)+"日");

break;

}

c_beginadd(CalendarDAY_OF_YEAR, 1);

}

可以这样试试，应该能理解吧。如有不懂再问我

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