Java获取当前时间的年月日时分秒

package com.excel;

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

public class Test {
public static void main(String[] args) throws Exception {
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());

Date date = new Date();
System.out.println(date);

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String dateNowStr = sdf.format(date);
System.out.println("格式化后的日期：" + dateNowStr);

String str = "2012-1-13 17:26:33"; // 要跟上面sdf定义的格式一样
Date today = sdf.parse(str);
System.out.println("字符串转成日期：" + today);
}
}

获取某个日期是星期几

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
Calendar c = Calendar.getInstance();
c.setTime(format.parse("2014-12-8"));
int dayForWeek = 0;
if (c.get(Calendar.DAY_OF_WEEK) == 1) {
dayForWeek = 7;
} else {
dayForWeek = c.get(Calendar.DAY_OF_WEEK) - 1;
}
System.out.println(dayForWeek);