Java Calendar 使用代码示例介绍，javacalendar,java Calenda

Java Calendar 使用代码示例介绍，javacalendar,java Calenda

java Calendar使用示例代码：

package cn.outofmemory.calendar.demo;   import java.text.SimpleDateFormat;   import java.util.Calendar;   import java.util.Date;   import java.util.GregorianCalendar;   public class CalendarDemo {       private static SimpleDateFormat date_format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");       public static void main(String[] args) {           //获取calendar实例;           Calendar calendar = Calendar.getInstance();           //判断calendar是不是GregorianCalendar类的实例;           if(calendar instanceof GregorianCalendar){               System.out.println("属于GregorianCalendar类的实例!");           }           //从calendar对象中获得date对象，当前时间;           Date dates =  calendar.getTime();           //格式化时间;           String date_str= date_format.format(dates);           System.out.println(date_str);           //设置月份05；代表日历的月份6月，因为月份从0开始。           calendar.set(Calendar.MONTH, 05);           int months = calendar.get(Calendar.MONTH);           System.out.println(months);  //输出05;           //设置日期为2011-07-24 09：59:50           calendar.set(2011, 06, 24, 9, 59, 50);             String getDate = date_format.format(calendar.getTime());           System.out.println(getDate);   //输出2011-07-24 09:59:50;           //比较日前大小;           if(new Date().getTime() > calendar.getTimeInMillis()){               System.out.println("当前日期在后!");           }else{               System.out.println("当前日期在前!");           }           //设置当前时间为:2011-07-24 11:06:00           calendar.setTime(new Date());             int year   = calendar.get(Calendar.YEAR);   //获取年;           int month  = calendar.get(Calendar.MONTH);  //获取月;           int date   = calendar.get(Calendar.DATE);   //获取天;           int hour   = calendar.get(Calendar.HOUR);   //获取小时;           int minute = calendar.get(Calendar.MINUTE); //获取分钟;           int second = calendar.get(Calendar.SECOND); //获取秒钟;           int hour_of_day = calendar.get(Calendar.HOUR_OF_DAY);    //第几个小时，           int day_of_month  = calendar.get(Calendar.DAY_OF_MONTH); //这天，在一个月内是第几天.            int day_of_week = calendar.get(Calendar.DAY_OF_WEEK);    //这天，在一周内，是第几天.           int day_of_year = calendar.get(Calendar.DAY_OF_YEAR);    //这天，在一年内，是第几天。           int week_of_year = calendar.get(Calendar.WEEK_OF_YEAR);  //这周，在一年内是第几周;           int week_of_month = calendar.get(Calendar.WEEK_OF_MONTH);//这周，在这个月是第几周;以以星为标准；           int zone_offset = calendar.get(Calendar.ZONE_OFFSET);    //获取时区;           int day_of_week_in_month = calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH);  //某月中第几周，按这个月1号算，1号起就是第1周，8号起就是第2周。以月份天数为标准            int r = calendar.get(Calendar.AM_PM);           if(r==calendar.AM){               System.out.println("现在是上午");           }           if(r==calendar.PM){               System.out.println("现在是下午");           }           System.out.println("==================================================");           System.out.println(year);           System.out.println(month);           System.out.println(date);           System.out.println(hour);           System.out.println(minute);           System.out.println(second);           System.out.println(hour_of_day);           System.out.println(day_of_month);           System.out.println(day_of_week);           System.out.println(day_of_year);           System.out.println(week_of_year);           System.out.println(week_of_month);           System.out.println(zone_offset);           System.out.println(day_of_week_in_month);       }   }  

Java获取当前日期的前一个月，前一天的时间

Calendar calendar = Calendar.getInstance();calendar.add(Calendar.DATE, -1);    //得到前一天calendar.add(Calendar.MONTH, -1);    //得到前一个月int year = calendar.get(Calendar.YEAR);int month = calendar.get(Calendar.MONTH)+1; //注意月份加一 // 判断当前日期是星期几<br>   // @param pTime 修要判断的时间<br>   //@return dayForWeek 判断结果<br>   // @Exception 发生异常<br>   public static int dayForWeek(String pTime) throws Exception {     format = new SimpleDateFormat("yyyy-MM-dd");     Calendar c = Calendar.getInstance();     c.setTime(format.parse(pTime));     int dayForWeek = 0;     if(c.get(Calendar.DAY_OF_WEEK) == 1){       dayForWeek = 7;     }else{       dayForWeek = c.get(Calendar.DAY_OF_WEEK) - 1;     }     return dayForWeek;  }