java获取昨天年月入和今天年月日 java获取当前年月日字符串

package com.sysc.simple;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class DateUtils {
public static void show() throws ParseException {
//获取当前日期
Calendar now = Calendar.getInstance();
int year = now.get(Calendar.YEAR);
int month = now.get(Calendar.MONTH) + 1;//注意月份
int day = now.get(Calendar.DAY_OF_MONTH);
int hour = now.get(Calendar.HOUR_OF_DAY);
int minute = now.get(Calendar.MINUTE);
int second = now.get(Calendar.SECOND);
long millis = now.getTimeInMillis();
System.out.println(now.getTime());
System.out.println(year + month + day + hour + minute + second + millis);
//日期格式化打印
Date d = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String dateNowStr = sdf.format(d);
System.out.println("格式化后的日期：" + dateNowStr);
//字符串解析为日期
String str = "2014-9-1 13:08:28";
Date today = sdf.parse(str);
System.out.println("字符串转成日期：" + today);
}
}