谁能帮我计算一下如何计算 100 年后的哪一天？ [复制]

Question

包分配2；

导入 java.util.Scanner;

公开课作业2 {

public static void main(String[] args) {
    Scanner stdIn = new Scanner(System.in);
    System.out.print("What is today?: ");
    String day = stdIn.nextLine();
    System.out.print("What year is it?: ");
    int year = stdIn.nextInt();

//for when the year IS a leap year

    if (day == "Tuesday" || (year % 400 == 0) || (year % 4 == 0) && (year % 100 != 0)) {
        System.out.println("In 100 years from " + day     " will be a Monday")
    } else if (day == "Wednesday" || (year % 400 == 0) || (year % 4 == 0) && (year % 100 != 0)) {
        System.out.println("In 100 years from " + day " will be a Tuesday")
    } else if (day == "Thursday" || (year % 400 == 0) || (year % 4 == 0) && (year % 100 != 0)) {
        System.out.println("In 100 years from " + day " will be a Wednesday")
    } else if (day == "Friday" || (year % 400 == 0) || (year % 4 == 0) && (year % 100 != 0)) {
        System.out.println("In 100 years from " + day " will be a Thursday")
    } else if (day == "Saturday" || (year % 400 == 0) || (year % 4 == 0) && (year % 100 != 0)) {
        System.out.println("In 100 years from " + day " will be a Friday")
    } else if (day == "Sunday" || (year % 400 == 0) || (year % 4 == 0) && (year % 100 != 0)) {
        System.out.println("In 100 years from " + day " will be a Saturday")
    }else if (day == "Monday" || (year % 400 == 0) || (year % 4 == 0) && (year % 100 != 0)) {
        System.out.println("In 100 years from " + day " will be a Sunday")



//This is for when the year IS NOT a leap year

    } else if (day == "Monday" || (year % 100 = 0)) {
        System.out.println("In 100 years from " + day " will be a Saturday")
    } else if (day == "Tuesday" || (year % 100 = 0)) {
        System.out.println("In 100 years from " + day " will be a Sunday")
    } else if (day == "Wednesday" || (year % 100 = 0)) {
        System.out.println("In 100 years from " + day " will be a Monday")
    } else if (day == "Thursday" || (year % 100 = 0)) {
        System.out.println("In 100 years from " + day " will be a Tuesday")
    } else if (day == "Friday" || (year % 100 = 0))
        System.out.println ("In 100 years from " + day " will be a Wednesday")
    } else if (day == "Saturday" || (year % 100 = 0))
        System.out.println("In 100 years from " + day " will be a Thursday"){
    } else if (day == "Sunday" || (year % 100 = 0))
        System.out.println("In 100 years from " + day " will be a Friday")
} 

}

编辑：这是我的大脑逻辑..如果你能理解它..这不是 java 逻辑。但是，如果您能阅读它，它会向您展示我所坚持的内容。

Answer 1

我认为你的问题的答案很大程度上取决于你的教练希望你从练习中得到什么。

如果目标只是尽可能高效地完成工作，那么您可以使用 Java 类库中的日期相关类或第三方日期库。

您将使用哪些取决于您使用的 Java 版本。 对于 Java 6 或 7，您将使用 java.util.Date 和相关类。对于 Java 8，您将使用新的 java.time 类。

在 Java 6 或 7 中，您还可以使用第三方库 Joda-Time 库。 该库的作者也是 Java 8 java.time 库的主要贡献者，因此它们很相似。

或者，也许，你的老师希望你自己做数学？

无论如何，我不赞成简单地给某人回答显然是家庭作业的问题，所以我把剩下的留给你。

Answer 2

好的，我添加几行代码以从输入日期代码中获取 100 之后的日期代码如下：

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

public class Assignment2 {

    public static void main(String[] args) {
        Scanner stdIn = new Scanner(System.in);
        System.out.print("What is today in format (yyyy/MM/dd) eg. 2015/08/03 ?: ");
        String day = stdIn.nextLine();
        System.out.print("What year is it?: ");
        int year = stdIn.nextInt();
        System.out.println("100 years from " + day + " will be a ");

        //getting calendar instance
        Calendar after100Year = Calendar.getInstance();

        //date time format for conversion or parsing
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd");
        try {
            //Prasing string input date to date object
            Date inputDate = dateFormat.parse(day);
            //set time to calendar instance
            after100Year.setTime(inputDate);

            //add 100 year in input date
            after100Year.add(Calendar.YEAR, 100);
            System.out.println("After 100 year date will be : " + dateFormat.format(after100Year.getTime()));

        } catch (ParseException ex) {
            ex.printStackTrace();
        }

        if (year % 400 == 0) {
            System.out.println("This is a leap year");
        } else if ((year % 4 == 0) && (year % 100 != 0)) {
            System.out.println("This is a leap year");
        } else {
            System.out.println("This is not a leap year.");
        }

    }
}