Date、String、long、Calendar类型之间的转化及时间加减

1.Calendar 转化 String
//获取当前时间的具体情况,如年,月,日,week,date,分,秒等
Calendar calendat = Calendar.getInstance();

SimpleDateFormat sdf = new SimpleDateFormat(“yyyy-MM-dd”);
String date = sdf.format(calendar.getTime());

 
2.String 转化Calendar

String str=”2010-5-27″;
SimpleDateFormat sdf= new SimpleDateFormat(“yyyy-MM-dd”);

Date date =sdf.parse(str);

Calendar calendar = Calendar.getInstance();

calendar.setTime(date);

3.Date 转化String

SimpleDateFormat sdf= new SimpleDateFormat(“yyyy-MM-dd”);

String dateStr=sdf.format(new Date());

4.String 转化Date
String str=”2010-5-27″;

SimpleDateFormat sdf= new SimpleDateFormat(“yyyy-MM-dd”);

Date birthday = sdf.parse(str);

5.Date 转化Calendar

Calendar calendar = Calendar.getInstance();
calendar.setTime(new java.util.Date());

6.Calendar转化Date

Calendar calendar = Calendar.getInstance();
java.util.Date date =calendar.getTime();

7.Calendar转long

long l = ca.getTimeInMillis();
ca.setTime(d);
ca.setTimeInMillis(l);

8、Calendar加减时间

calendar.setTime(date);//時間转calendar
calendar.add(Calendar.DAY_OF_MONTH, 1);//加减时间，前面：时分秒，后门是值，值可以为负数，就是减时间