Calculate the day of the week for a date using Java

Without further ado, let's go straight to the example code

Specific code:

DayOfWeek4Birthday.java

package com.gua;

import java.util.Calendar;
import java.util.GregorianCalendar;
import java.io.*;
import static java.lang.System.out;

/**
 * Created by 2gua on 2014/9/27.
 * DayOfWeek4Birthday : depending on what day of the week you are looking for, 
 *            For example, look up "what day of the week is your birthday?" 
 */

public class DayOfWeek4Birthday {
  private String[] date; // Save input data: year, month, date. 

  // Calculate the day of the week for which the date data is entered. 
  private void caculateData() {
    GregorianCalendar gc = new GregorianCalendar();
    final char[] day_of_week = {' day ','1','2','3','4','5','6'};
    int year = gc.get(Calendar.YEAR); // From the current year. 
    char week;

    for(int i = year; i<= year + Integer.valueOf(date[0]) - 1; i++) {
      gc.set(i, Integer.valueOf(date[1]) - 1, Integer.valueOf(date[2]));

      week = day_of_week[gc.get(Calendar.DAY_OF_WEEK) - 1];

      out.println(i + " years " + date[1] + " month " + date[2] + " Number is week " + week + " . ");
    }
  }

  // Enter date data. 
  private void inputData() {
    InputStreamReader is = new InputStreamReader(System.in);
    BufferedReader br = new BufferedReader(is);

    try {
      out.print(" Please enter year range and date, format: year number   A few months   Number ( 5 9 15 ), enter the end: ");
      String in = br.readLine();
      date   = in.split(" ");
      out.println(" Input results: " + date[0] + " A number of years, " + date[1] + " month " + date[2] + " Number. ");
    }
    catch(Exception e) {
      out.println(" Uh-oh, something went wrong -_- . sorry ! ");
    } finally {
      try {
        br.close();
        is.close();
      } catch (IOException e) {
        out.println("IO Error! -_- . sorry ! ");
      }
    }
  }

  public static void main(String[] args) {
    DayOfWeek4Birthday dayOfWeek4Birthday = new DayOfWeek4Birthday();

    dayOfWeek4Birthday.inputData();
    dayOfWeek4Birthday.caculateData();
  }
}

Let's say I want to see what day of the week September 15th is every year for five years from this year.

The results are as follows:

 Please enter year range and date, format: year number   A few months   Number ( 5 9 15 ), enter the end: 5 9 15
 Input results: 5 A number of years, 9 month 15 Number. 
2014 years 9 month 15 Number is week 1 . 
2015 years 9 month 15 Number is week 2 . 
2016 years 9 month 15 Number is week 4 . 
2017 years 9 month 15 Number is week 5 . 
2018 years 9 month 15 Number is week 6 . 

Process finished with exit code 0

Remember to close the stream after use.

The above is the practice of JDK 6, which can be used in JDK 7 and JDK 8 automatic resource management（ARM） New features, refactoring inputData() Methods:

// Enter date data. 
private void inputData() {
  try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
    out.print(" Please enter year range and date, format: year number   A few months   Number ( 5 9 15 ), enter the end: ");
    String in = br.readLine();
    date   = in.split(" ");
    out.println(" Input results: " + date[0] + " A number of years, " + date[1] + " month " + date[2] + " Number. ");
  }
  catch(Exception e) {
    out.println(" Uh-oh, something went wrong -_- . sorry ! ");
  }
}

Of course, remember to set the module language level accordingly to JDK 7 or JDK 8. JDK 6 and below will not pass.

conclusion

The above is the whole content of this article, I hope the content of this article can help you to learn or use Java, if you have any questions, you can leave a message to communicate.