java中的时间

import java.util.Date; 
import java.util.Calendar; 

import java.text.SimpleDateFormat; 

将Date转换为String

Date now=new Date();

SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");//可以方便地修改日期格式

String now_time = dateFormat.format( now ); //时间转换成固定格式的String了
System.out.println(now_time);

Calendar c = Calendar.getInstance();//可以对每个时间域单独修改

int year = c.get(Calendar.YEAR); 
int month = c.get(Calendar.MONTH); 
int date = c.get(Calendar.DATE); 
int hour = c.get(Calendar.HOUR_OF_DAY); 
int minute = c.get(Calendar.MINUTE); 
int second = c.get(Calendar.SECOND); 
System.out.println(year + "/" + month + "/" + date + " " +hour + ":" +minute + ":" + second); 

将String转换成时间Date

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

java.util.Date time=null;
try {
   time= sdf.parse(sdf.format(new Date()));

} catch (ParseException e) {

   e.printStackTrace();
}