Java tutorial
//package com.java2s; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; public class Main { public static final SimpleDateFormat HTTP_DATE_FORMAT = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss"); /** * Returns yesterday's date formatted according to the HTTP specification * standard date format. * * @return a formatted string. */ public static String getExpiredHttpDateString() { Calendar cal = Calendar.getInstance(); cal.add(Calendar.DAY_OF_YEAR, -1); return getHttpDateString(cal.getTime()); } /** * Formats a Date according to the HTTP specification standard date format. * * @param date the Date to format. * @return a formatted string. */ public static String getHttpDateString(Date date) { return HTTP_DATE_FORMAT.format(date) + " GMT"; } }