java时间加减 自己选合适的

public static String getBeforeDate(Date date,int days){SimpleDateFormat df = new SimpleDateFormat(FORMAT_DAY);Calendar calendar = Calendar.getInstance();   calendar.setTime(date);calendar.set(Calendar.DAY_OF_YEAR,calendar.get(Calendar.DAY_OF_YEAR) - days);return df.format(calendar.getTime());}public static String getAfterDate(Date date,int days){SimpleDateFormat df = new SimpleDateFormat(FORMAT_DAY);Calendar calendar = Calendar.getInstance();   calendar.setTime(date);calendar.set(Calendar.DAY_OF_YEAR,calendar.get(Calendar.DAY_OF_YEAR) + days);return df.format(calendar.getTime());}

public static String getBeforeDate(Date date,int days){SimpleDateFormat df = new SimpleDateFormat(FORMAT_DAY);Date beforeDate = new Date(date.getTime() - days * 24 * 60 * 60 * 1000);return df.format(beforeDate);}public static String getAfterDate(Date date,int days){SimpleDateFormat df = new SimpleDateFormat(FORMAT_DAY);Date beforeDate = new Date(date.getTime() + days * 24 * 60 * 60 * 1000);return df.format(beforeDate);}

DateFormat df=new SimpleDateFormat("yyyy-MM-dd EE hh:mm:ss"); System.out.println(df.format(new Date())); Date date = new Date(); DateFormat shortDate=DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT); DateFormat mediumDate =DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM); DateFormat longDate =DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG); DateFormat fullDate =DateFormat.getDateTimeInstance(DateFormat.FULL, DateFormat.FULL); system.out.println(shortDate.format(date)); System.out.println(mediumDate.format(date)); System.out.println(longDate.format(date)); System.out.println(fullDate.format(date)); 08-4-15 下午3:24 2008-4-15 15:24:31 2008年4月15日 下午03时24分31秒 2008年4月15日 星期二 下午03时24分31秒CST Calendar c = Calendar.getInstance(); c.add(Calendar.MONTH, 1); // 目前加1月 System.out.println(df.format(c.getTime())); c.add(Calendar.HOUR, 3); // 目前加3小 System.out.println(df.format(c.getTime())); c.add(Calendar.YEAR, -2); // 目前2年 System.out.println(df.format(c.getTime())); c.add(Calendar.DAY_OF_WEEK, 7); // 目前的加7天 System.out.println(df.format(c.getTime()));