date日期类型与String类型的相互转化

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.apache.log4j.Logger;

import com.fourstar.log4j.HelloLog4j;

public class DateUtil {
    private static final Logger log = Logger.getLogger(HelloLog4j.class);//获得当前类
    public static Date toDate(String dateStr) {
        Date date = null;
        SimpleDateFormat formater = new SimpleDateFormat();
        formater.applyPattern("yyyy-MM-dd hh:m:ss");
        try {
            date = formater.parse(dateStr);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;

    }

    public static Date toDate(String dateStr, String f) {
        Date date = null;
        SimpleDateFormat formater = new SimpleDateFormat();
        formater.applyPattern(f);
        try {
            date = formater.parse(dateStr);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;

    }

    public static String toString(Date date) {

        String time;
        SimpleDateFormat formater = new SimpleDateFormat();

        formater.applyPattern("yyyy-MM-dd hh:m:ss");
        time = formater.format(date);

        return time;
    }

    public static String toString(Date date, String f) {
        String time;
        SimpleDateFormat formater = new SimpleDateFormat();
        formater.applyPattern(f);
        time = formater.format(date);
        return time;
    }

    public static void main(String[] args) {
        Date todayDate = new Date();//date类型
        System.out.println(todayDate);
        String t = DateUtil.toString(todayDate,"yyyy-MM-dd hh:m:ss");//string类型
        System.out.println(t);
        todayDate = DateUtil.toDate(t, "yyyy-MM-dd hh:m:ss");//date类型
        System.out.println(todayDate);
    }

}