如何判断输入的文本是否日期格式

try{    Date.valueOf(String aString);}catch(Exception ex){    System.err.println("The format of string is not correct");}

或者



public class forother {    public static void main(String[] args){                SimpleDateFormat s=new SimpleDateFormat("yyyy-MM-dd' 'HH:mm:ss");               String ooo="2005-02-18 15:39:15";        String ppp="2005-02-01 15:25:15";              try{        Date tt=s.parse(ooo);        Date yy=s.parse(ppp);        long aa;        if(tt.getTime()>yy.getTime())            aa=tt.getTime()-yy.getTime();        else            aa=yy.getTime()-tt.getTime();        long date=aa/1000/60/60/24;        System.out.println("***");        System.out.println("hahahha"+date);        System.out.println("*******");        }catch(Exception e){                    }           }}