The use of date and calendar classes in Java

The date class in JAVA is: Date class Calendar class: Calendar class

Now, let us take a look at the usage of Date class!

import java.util.*;  
import java.text.*;  
  
public class DateTest {  
    public static void main(String[] args) {  
          
      Date today = new Date();     //获取当前系统时间  
      System.out.println(today);  
        
      //定义日期输出格式  
      SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");  
        
      //将当前日期转换成指定日期格式输出  
      String day =sdf.format(today);  
      System.out.println(day);  
        
        
      //指定时间  
      String today1 ="2016年7月13日 10:58:54";  
      try {  
      //将指定时间转换成日期格式输出  
        Date date=sdf.parse(today1);  
        System.out.println(date);  
          
    } catch (ParseException e) {  
          
        e.printStackTrace();  
    }  
  
      //日历类的使用  
  
      Calendar c =Calendar.getInstance();  
      int year =c.get(Calendar.YEAR);  
      int month=c.get(Calendar.MONTH)+1;//从0月开始，需要加一  
      int day1 = c.get(Calendar.DAY_OF_MONTH);  
      int hour =c.get(Calendar.HOUR);  
      int second = c.get(Calendar.SECOND);  
      int min =c.get(Calendar.MINUTE);  
      System.out.println("当前时间："+year+"年"+month+"月"+day1+"日"  
                         +hour+"日"+min+"分"+second+"秒");  
        
    }  
}

The running result is:

It should be noted that the code SimpleDateFormat sdf = new SimpleDateFormat("yyyy year MM month dd day HH: mm: ss");

1. Don’t write MM in lowercase mm, otherwise you will get wrong results.
2. There are spaces in the middle, and when converting a string into a date, you need to pay attention to the one-to-one correspondence between the spaces in the string and the spaces in the date in the specified format.
3. You can change the letters in HH: mm: ss of yyyy year MM month dd day to see what kind of result you will get

The above is the date class and calendar class in Java For more related content, please pay attention to the PHP Chinese website (m.sbmmt.com)!