出自：http://hi.baidu.com/itfuck_/item/803662469cdf7baa61d7b945

1:

import java.util.*;

int y,m,d,h,mm;

Calendar c = Calendar.getInstance();

y = c.get(Calendar.YEAR); //年

m = c.get(Calendar.MONTH) + 1; //月

d = c.get(Calendar.DAY_OF_MONTH); //日

h = c.get(Calendar.HOUR); //时 12小时制

h2 = c.get(Calendar.HOUR_OF_DAY);//时 24小时制

mm = c.get(Calendar.MINUTE); //分

2:

java.util.Date d = new java.util.Date();

java.text.SimpleDateFormat dformat = new java.text.SimpleDateFormat("yyyy-MM-dd");

String datetime = dformat.format(d); System.out.println(datetime);

3:

import java.util.*; import java.text.*;

Date now = new Date();

DateFormat defaultFormat = DateFormat.getDateInstance();

DateFormat shortFormat = DateFormat.getDateInstance(DateFormat.SHORT);

DateFormat mediumFormat = DateFormat.getDateInstance(DateFormat.MEDIUM);

DateFormat longFormat = DateFormat.getDateInstance(DateFormat.LONG);

DateFormat fullFormat = DateFormat.getDateInstance(DateFormat.FULL);

String defaultDate = defaultFormat.format(now);

String shortDate = shortFormat.format(now);

String mediumDate = mediumFormat.format(now);

String longDate = longFormat.format(now);

String fullDate = fullFormat.format(now);

  System.out.println("(Default) Today :" + defaultDate); 

System.out.println("(SHORT) Today : " + shortDate);

System.out.println("(MEDIUM) Today :" + mediumDate);

System.out.println("(LONG) Today : " + longDate); System.out.println("(FULL) Today : " + fullDate);

4.

如果只要年月日,可以用subString()截取. 或者用这个

String time=new SimpleDateFormat("yyyy-MM-dd").format(Calendar.getInstance().getTime);

5.

Date currentTime = new Date(); 

SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");

String dateString = formatter.format(currentTime);

dataString 的格式就是2007-03-08这类型