Android : Date Object Sample (Calendar, SimpleDateFormat )

     /**
     *  Unix TimeStamp > Date String 변환
     * @param dbTimeStamp
     * @return
     */
     public static String timeStampToSimepleDateString(String dbTimeStamp){
         
          SimpleDateFormat dateFormat = new SimpleDateFormat ("yy/MM/dd");
          SimpleDateFormat timeFormat = new SimpleDateFormat ("HH:mm분");
         
          //Yesterday
          Calendar today = Calendar.getInstance ( );
          today.add ( Calendar.DATE, -1 );
          Date yesterday = today.getTime ( );
          String yesDate = dateFormat.format(yesterday);
         
          //Current date
          Date now = new Date();
          String curDate = dateFormat.format(now);
         
          //MySQL DB TimStamp > JAVA Date
          Date unixDate = new Date(1000l*Long.parseLong(dbTimeStamp)) ;
          String dbDate = dateFormat.format(unixDate);
         
         
          if(curDate.equals(dbDate)){ // Current
               return timeFormat.format(unixDate);
          } else if(yesDate.equals(dbDate)){ //Yesterday
               return "어제";
          } else { // Another 
               return dbDate; //yyyy MM dd
          }