import java.text.Format;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
 
public class $ {
 
    public static void main(String[] args) {
        Format f = new SimpleDateFormat("yyyy-MM-dd");
 
        Date today = new Date();
        System.out.println("今天是:" + f.format(today));
 
        Calendar c = Calendar.getInstance();
        c.setTime(today);
        c.add(Calendar.DAY_OF_MONTH, 1);// 今天+1天
 
        Date tomorrow = c.getTime();
        System.out.println("明天是:" + f.format(tomorrow));
    }
}
 
結果：
今天是:2013-10-09
明天是:2013-10-10
 

因專案需要，這裡附上我在Hibernate中實現取一週資料的Dao程式碼：

 public List exportOneweekinfo() throws HibernateException{
        Session session = HibernateSessionFactory.getSession();
        Transaction tx = session.beginTransaction();
        Format ctime = new SimpleDateFormat("yyyy-MM-dd");
        Date today = new Date();   
        String todaydate = ctime.format(today);   //當前時間日期 
        Calendar c = Calendar.getInstance();
        c.setTime(today);
        c.add(Calendar.DAY_OF_MONTH, -7);   
        Date  before = c.getTime();
        String beforeweekdate = ctime.format(before);    //一週開始的時間
        System.out.println("todaydate"+todaydate);
        System.out.println("beforweekdate"+beforeweekdate);  
        Query query = session.createQuery("select e from Information as e where e.reporttime>='"+beforeweekdate+"' and e.reporttime <= '"+ todaydate +"'");   //hql語句
//        query.setMaxResults(20);  //設定最大顯示的個數
        List list = query.list();
        tx.commit();
        HibernateSessionFactory.closeSession();
        return list;
    }