Javaは、指定された日付に基づいて週の月曜日と日曜日を計算します.

public static void main(String[] args) throws ParseException {  

         SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd"); //        
         Calendar cal = Calendar.getInstance();  
         Date time=sdf.parse("2015-9-4 14:22:47");
         cal.setTime(time);  
         System.out.println("      :"+sdf.format(cal.getTime())); //         

         //             ，            ，      ，          
         int dayWeek = cal.get(Calendar.DAY_OF_WEEK);//                 
         if(1 == dayWeek) {  
            cal.add(Calendar.DAY_OF_MONTH, -1);  
         }  

        cal.setFirstDayOfWeek(Calendar.MONDAY);//          ，                    

        int day = cal.get(Calendar.DAY_OF_WEEK);//                 
        cal.add(Calendar.DATE, cal.getFirstDayOfWeek()-day);//       ，                        
        System.out.println("         ："+sdf.format(cal.getTime()));
        System.out.println(cal.getFirstDayOfWeek()+"-"+day+"+6="+(cal.getFirstDayOfWeek()-day+6));

        cal.add(Calendar.DATE, 6);
        System.out.println("         ："+sdf.format(cal.getTime()));  

    }