Java日期与String转换等处理

package com.zhh;


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


public class TestDate {


public static void main(String[] args) throws ParseException {
Calendar now = Calendar.getInstance();
System.out.println("年: " + now.get(Calendar.YEAR));
System.out.println("月: " + (now.get(Calendar.MONTH) + 1) + "");
System.out.println("日: " + now.get(Calendar.DAY_OF_MONTH));
System.out.println("时: " + now.get(Calendar.HOUR_OF_DAY));
System.out.println("分: " + now.get(Calendar.MINUTE));
System.out.println("秒: " + now.get(Calendar.SECOND));
System.out.println("当前时间毫秒数：" + now.getTimeInMillis());
System.out.println(now.getTime());
System.out.println(getDateTime("2016-12-12 12:23:33"));
System.out.println(date2String(new Date()));
System.out.println(dateTime2String(new Date()));
}


public static Date getDate(String str) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date today = null;
try {
today = sdf.parse(str);
} catch (ParseException e) {
e.printStackTrace();
}
return today;
}


public static Date getDateTime(String str) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date today = null;
try {
today = sdf.parse(str);
} catch (ParseException e) {
e.printStackTrace();
}
return today;
}


public static String date2String(Date date) {
String str = new SimpleDateFormat("yyyy-MM-dd").format(date);
return str;
}


public static String dateTime2String(Date date) {
String str = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(date);
return str;
}
}