Here you can find the source of getWeekOfYear(int startDay, Calendar dt)
| Parameter | Description |
|---|---|
| startDay | Week start day (0 sunday -> 6 saturday) |
| dt | Date |
public static int getWeekOfYear(int startDay, Calendar dt)
//package com.java2s; /*/*w w w . j ava2s.c om*/ * Copyright (c) 2013 The Johns Hopkins University/Applied Physics Laboratory * All rights reserved. * * This material may be used, modified, or reproduced by or for the U.S. * Government pursuant to the rights granted under the clauses at * DFARS 252.227-7013/7014 or FAR 52.227-14. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * NO WARRANTY. THIS MATERIAL IS PROVIDED "AS IS." JHU/APL DISCLAIMS ALL * WARRANTIES IN THE MATERIAL, WHETHER EXPRESS OR IMPLIED, INCLUDING (BUT NOT * LIMITED TO) ANY AND ALL IMPLIED WARRANTIES OF PERFORMANCE, * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF * INTELLECTUAL PROPERTY RIGHTS. ANY USER OF THE MATERIAL ASSUMES THE ENTIRE * RISK AND LIABILITY FOR USING THE MATERIAL. IN NO EVENT SHALL JHU/APL BE * LIABLE TO ANY USER OF THE MATERIAL FOR ANY ACTUAL, INDIRECT, * CONSEQUENTIAL, SPECIAL OR OTHER DAMAGES ARISING FROM THE USE OF, OR * INABILITY TO USE, THE MATERIAL, INCLUDING, BUT NOT LIMITED TO, ANY DAMAGES * FOR LOST PROFITS. */ import java.util.Calendar; import java.util.GregorianCalendar; import java.util.TimeZone; public class Main { private static final int ms1d = 86400000; private static final int ms7d = 7 * ms1d; /** * Calculates week number for given date This function is derived from JavaScript implementation used in OE * * @param startDay Week start day (0 sunday -> 6 saturday) * @param dt Date * @return Week number */ public static int getWeekOfYear(int startDay, Calendar dt) { // adapted from http://www.merlyn.demon.co.uk/weekcalc.htm // Used to compute offset based on epi week start day (0 sunday -> 6 // saturday), defaults to 1 int offset = (((Math.abs(startDay - 6)) + 5) % 7); // epi week start day // offset Calendar d3 = new GregorianCalendar(dt.get(Calendar.YEAR), dt.get(Calendar.MONTH), dt.get(Calendar.DATE), 0, 0, 0); d3.set(Calendar.MILLISECOND, 0); d3.add(Calendar.DAY_OF_YEAR, offset); double DC3 = d3.getTimeInMillis() / ms1d; // an Absolute Day Number double AWN = Math.floor(DC3 / 7); // an Absolute Week Number Calendar yCal = Calendar.getInstance(TimeZone.getTimeZone("UTC")); yCal.clear(); yCal.setTimeInMillis((long) AWN * ms7d);// int Wyr = yCal.get(Calendar.YEAR); Calendar firstCal = Calendar.getInstance(TimeZone .getTimeZone("UTC")); firstCal.clear(); firstCal = new GregorianCalendar(Wyr, 0, 7, 0, 0, 0); firstCal.set(Calendar.MILLISECOND, 0); int t = (int) (AWN - (int) Math.floor(firstCal.getTimeInMillis() / ms7d) + 1); return t; } }