1。


SimpleDateFormat tempDate = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

String datetime = tempDate.format(new java.util.Date());

2。


Calendar now=Calendar.getInstance();

String time=now.get(Calendar.YEAR)+"-"+(now.get(Calendar.MONTH)+1)+"-"+now.get(Calendar.DAY_OF_MONTH)+" "+now.get(Calendar.HOUR_OF_DAY)+":"+now.get(Calendar.MINUTE)+":"+now.get(Calendar.SECOND);


更详细的介绍如下:


一. 获取当前系统时间和日期并格式化输出:


import java.util.Date;

import java.text.SimpleDateFormat;


public class NowString {

   public static void main(String[] args) {    

   SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式

      System.out.println(df.format(new Date()));// new Date()为获取当前系统时间

   }

}


二. 在数据库里的日期只以年-月-日的方式输出,可以用下面两种方法:


1、用convert()转化函数:


String sqlst = "select convert(varchar(10),bookDate,126) as convertBookDate from roomBook where bookDate  between '2007-4-10' and '2007-4-25'";


System.out.println(rs.getString("convertBookDate"));


2、利用SimpleDateFormat类:


先要输入两个java包:


import java.util.Date;

import java.text.SimpleDateFormat;


然后:


定义日期格式:SimpleDateFormat sdf = new SimpleDateFormat(yy-MM-dd);


sql语句为:String sqlStr = "select bookDate from roomBook where bookDate between '2007-4-10' and '2007-4-25'";


输出:


System.out.println(df.format(rs.getDate("bookDate")));


-------------------------------------

java中获取当前日期和时间的方法


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

  import   java.text.SimpleDateFormat;  
  

  public   class   TestDate{  
  public   static   void   main(String[]   args){  
  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   hehe   =   dateFormat.format(   now   );  
  System.out.println(hehe);  
  

  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);  
  }  
  }