Here you can find the source of getWeek(SimpleDateFormat df, String dateStr)
public static int getWeek(SimpleDateFormat df, String dateStr)
//package com.java2s; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; public class Main { public static int getWeek(SimpleDateFormat df, String dateStr) { Calendar c = Calendar.getInstance(); try {/*from w w w . j a v a 2s . c o m*/ c.setTime(df.parse(dateStr)); } catch (ParseException e) { e.printStackTrace(); } int week = c.get(Calendar.DAY_OF_WEEK) - 1; if (0 == week) { week = 7; } return week; } public static Date parse(SimpleDateFormat df, String date) { try { return df.parse(date); } catch (ParseException e) { return null; } } }