toString wrote:
import java.util.Date;

public class test {
  public static void main(String[] args){
    Date date = new Date();
  
    int year=date.getYear()+1900;
    int month=date.getMonth()+1;
    int day=date.getDate();
    
    System.out.println("It is "+year+"/"+month+"/"+day+" (YYYY/MM/DD)today.");
  }
}

import java.util.*;

public class Mydate
{
  public static void main(String[] args) 
  {
    Calendar cal  = Calendar.getInstance();
    
    String date_now=cal.get(cal.YEAR)+"年"+(cal.get(cal.MONTH)+1)+"月"+cal.get(cal.DATE)+"日 ";
    String time_now=cal.get(cal.HOUR_OF_DAY)+"时"+cal.get(cal.MINUTE)+"分"+cal.get(cal.SECOND)+"秒";
    
    System.out.println(date_now);
    System.out.println(time_now);

  }
}

不懂 wrote:
请问代码中的年为何要+1900 月为何要+1 呢？日为什么不用加？？ 请指教！！

getYear()
Deprecated. As of JDK version 1.1, replaced by Calendar.get(Calendar.YEAR) - 1900.

getMonth()
Deprecated. As of JDK version 1.1, replaced by Calendar.get(Calendar.MONTH).

why wrote:
http://java.sun.com/j2se/1.4.1/docs/api/java/util/Date.html

getYear()
Deprecated. As of JDK version 1.1, replaced by Calendar.get(Calendar.YEAR) - 1900.

getMonth()
Deprecated. As of JDK version 1.1, replaced by Calendar.get(Calendar.MONTH).
Returns a number representing the month that contains or begins with
the instant in time represented by this Date object. The value returned
is between 0 and 11, with the value 0 representing January.

These methods are deprecated, use java.util.Calendar instead:
http://java.sun.com/j2se/1.4.1/docs/api/java/util/Calendar.html