日期类Date和日期的格式化SimpleDateFormat

Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
//将日期转换成字符串
String str = sdf.format(date);
//把字符串转换成日期
String str2= "1995/12/16 23:12:45";
try {
Date date1 = sdf.parse(str2);
System.out.print(date1); //Sat Dec 16 23:12:45 CST 1995
//获得毫秒数
Long ms = date1.getTime();
System.out.print(ms); //819126765000
} catch (ParseException e) {
e.printStackTrace();
}