Date currentTime = new Date();
   SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
   String dateString = formatter.format(currentTime);
4.时间加减得到天数 
public static long getDaySub(String beginDateStr,String endDateStr) 
{ 
long day=0; 
java.text.SimpleDateFormat format = new java.text.SimpleDateFormat("yyyy-MM-dd"); 
java.util.Date beginDate; 
java.util.Date endDate; 
try 
{ 
beginDate = format.parse(beginDateStr); 
endDate= format.parse(endDateStr); 
day=(endDate.getTime()-beginDate.getTime())/(24*60*60*1000); 
//System.out.println("相隔的天数="+day); 
} catch (ParseException e) 
{ 
// TODO 自动生成 catch 块 
e.printStackTrace(); 
} 
return day; 
} 原文:http://www.cnblogs.com/it-xiaoJiang/p/5767290.html