java使用格式String型转成Date型

public class TimeTwo {
    public static void main(String[] args) throws ParseException{
        String s = "2018-08-12 12:02:23";

            SimpleDateFormat g = new SimpleDateFormat("yyyy-MM-dd MM:mm:ss");
            try{
                Date h = g.parse(s);
//                System.out.println(h);
            }catch (ParseException e){
                e.printStackTrace();
            }
        //格式String型转成Date型
        DateFormat format3 = DateFormat.getDateInstance(DateFormat.LONG,Locale.SIMPLIFIED_CHINESE);
        try{
            System.out.println("日期:"+format3.format(new Date()));

        }catch (Exception e){
            e.printStackTrace();
        }
    }
}