javaBasics篇（三）_java basics

The first java program.

1.输出当前时间：

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

public class HelloData {

        public static void main(String[] args) throws ParseException {
            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 d = new Date();
            System.out.println(d);
            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);

            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);
        }
    }


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2.输出当前时间：

import java.util.Date;

public class Hello {
    public static void main(String[] args) {
        System.out.println("hello data is"+":"+"data"+new Date());
    }
}

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