Java面试知识点：Date类、异常

我会带着你远行 2022-09-05 14:53 186阅读 0赞

# 问题：Java面试知识点：Date类、异常 #

答案：

1.Date类

代码如下：

（1）创建日期：

package com.xy;
    
    import java.util.Date;
    
    /**
     * @ProjectName: day01
     * @Package: com.xy
     * @ClassName: test01
     * @Author: 杨路恒
     * @Description:
     * @Date: 2021/8/17 0017 9:55
     * @Version: 1.0
     */
    public class test01 {
        public static void main(String[] args) {
            Date date=new Date();       //当前电脑中的时间
            System.out.println(date);
            Date date1=new Date(0L);    //从计算机的时间原点开始，过了指定毫秒的那个时间
            System.out.println(date1);
            long l = System.currentTimeMillis();
            long time = date.getTime();
            System.out.println(l);
            System.out.println(time);
        }
    }

（2）日期格式化：

package com.xy;
    
    import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    /**
     * @ProjectName: day01
     * @Package: com.xy
     * @ClassName: test02
     * @Author: 杨路恒
     * @Description:
     * @Date: 2021/8/17 0017 10:12
     * @Version: 1.0
     */
    public class test02 {
        public static void main(String[] args) throws ParseException {
            Date date=new Date();
            SimpleDateFormat simpleDateFormat=new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss ");
            String format = simpleDateFormat.format(date);
            System.out.println(format);
    
            String s="2021-8-17";
            SimpleDateFormat simpleDateFormat1=new SimpleDateFormat("yyyy-MM-dd");
            Date parse = simpleDateFormat1.parse(s);
            System.out.println(parse);
        }
    }
    
    
    package com.xy;
    
    import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    /**
     * @ProjectName: day01
     * @Package: com.xy
     * @ClassName: test03
     * @Author: 杨路恒
     * @Description:
     * @Date: 2021/8/17 0017 10:19
     * @Version: 1.0
     */
    public class test03 {
        public static void main(String[] args) throws ParseException {
            String start="2020年11月11日 0:0:0";
            String end="2020年11月11日 0:10:0";
    
            String s="2020年11月11日 0:03:47";
            String s1="2020年11月11日 0:10:11";
            SimpleDateFormat simpleDateFormat=new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
            Date date = simpleDateFormat.parse(s);
            Date date1 = simpleDateFormat.parse(s1);
            Date parse = simpleDateFormat.parse(start);
            Date parse1 = simpleDateFormat.parse(end);
            if (date.getTime()>=parse.getTime()&&date.getTime()<=parse1.getTime()){
                System.out.println("第一位参与");
            }
            else {
                System.out.println("第一位没参与");
            }
            if (date1.getTime()>=parse.getTime()&&date1.getTime()<=parse1.getTime()){
                System.out.println("第二位参与");
            }
            else {
                System.out.println("第二位没参与");
            }
        }
    }

（3）日期常用操作：

package com.xy;
    
    import java.time.Duration;
    import java.time.LocalDate;
    import java.time.LocalDateTime;
    import java.time.Period;
    import java.time.format.DateTimeFormatter;
    
    /**
     * @ProjectName: day01
     * @Package: com.xy
     * @ClassName: day04
     * @Author: 杨路恒
     * @Description:
     * @Date: 2021/8/17 0017 10:31
     * @Version: 1.0
     */
    public class test04 {
        public static void main(String[] args) {
            DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy年MM月dd日 HH:mm:ss");
            String s="2021年08月17日 16:21:00";
            LocalDateTime localDateTime = LocalDateTime.parse(s, dateTimeFormatter);
            LocalDateTime localDateTime1 = localDateTime.plusDays(1);
            String s1 = localDateTime.format(dateTimeFormatter);
            System.out.println(s1);
    
            LocalDateTime now = LocalDateTime.now();
            System.out.println(now);
            LocalDateTime localDateTime2 = LocalDateTime.of(2021, 8, 17, 16, 26);
            System.out.println(localDateTime2);
            System.out.println(now.getYear());      //获取年
            System.out.println(now.getMonth());     //获取月
            System.out.println(now.getDayOfMonth());        //获取日
            System.out.println(now.getDayOfWeek());
            System.out.println(now.getDayOfYear());
            System.out.println(now.getHour());
            System.out.println(now.getMinute());
            System.out.println(now.minusYears(1));
            System.out.println(now.withYear(2021));
            Period between = Period.between(localDateTime2.toLocalDate(),now.toLocalDate());
            System.out.println(between);
            System.out.println(between.getYears());
            System.out.println(between.getMonths());
            System.out.println(between.getDays());
            System.out.println(between.toTotalMonths());
            Duration between1 = Duration.between(now, localDateTime2);
            System.out.println(between1.getSeconds());
            System.out.println(between1.getNano());
            System.out.println(between1.toMillis());
        }
    }

2.异常

代码如下:

(1)Throws

package com.xy;
    
    /**
     * @ProjectName: day01
     * @Package: com.xy
     * @ClassName: test05
     * @Author: 杨路恒
     * @Description:
     * @Date: 2021/8/17 0017 17:14
     * @Version: 1.0
     */
    public class test05 {
        public static void main(String[] args) throws Exception {
            try {
                System.out.println(1/0);
            } catch (Exception e) {
                e.printStackTrace();
            }
            throw new Exception("异常");
        }
    }

（2）Throw

package com.xy;
    
    import java.util.Scanner;
    
    /**
     * @ProjectName: day01
     * @Package: com.xy
     * @ClassName: test06
     * @Author: 杨路恒
     * @Description:
     * @Date: 2021/8/17 0017 20:20
     * @Version: 1.0
     */
    public class test06 {
        public static void main(String[] args) {
            try {
                Scanner in=new Scanner(System.in);
                String s = in.nextLine();
                int i = Integer.parseInt(s);
                System.out.println(i);
                System.out.println("输出");
                System.out.println(1/0);
            } catch (NumberFormatException e) {
                System.out.println("执行");
                e.getMessage();
                String s = e.toString();
                System.out.println(s);
            }catch (ArithmeticException e){
                System.out.println("执行");
                e.printStackTrace();
            }
    
        }
    }
    
    class AgeOutOfBoundException extends NumberFormatException{
        public AgeOutOfBoundException() {
            super();
        }
    }

(3)异常

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