Java日期时间处理常用方法详解编程语言

    // 由字符串时间得到Date类型时间 
    public static Date getDateFrom(String strDate){ 
        try{ 
            SimpleDateFormat sdf =   new SimpleDateFormat("yyyy-MM-dd"); 
            Date date = sdf.parse(strDate); 
            return date; 
        } 
        catch(Exception ex){ 
            return null; 
        } 
    }

// 由Date类型时间得到字符串时间 
    public static String getDateStrFrom(Date date){ 
        try{ 
            Format formatter = new SimpleDateFormat("yyyy-MM-dd"); 
            return formatter.format(date); 
        } 
        catch(Exception ex){ 
            return null; 
        } 
    }

    /** 
     * 得到几天前的时间 
     *  
     * @param d 
     * @param day 
     * @return 
     */ 
    public static String getDateBefore(Date d, int day) { 
        Calendar now = Calendar.getInstance(); 
        now.setTime(d); 
        now.set(Calendar.DATE, now.get(Calendar.DATE) - day); 
         
        Format formatter = new SimpleDateFormat("yyyy-MM-dd"); 
        return formatter.format(now.getTime()); 
    }

        for(DateRangeHour drh:lsTen){ 
             
            for(Object obj:ls){ 
                DateHour d=(DateHour)obj; 
                 
                if(d.getDate().before(drh.getEndDate()) && d.getDate().after(drh.getStartDate())){ 
                    drh.hours+=d.getHours(); 
                } 
            } 
        }