Rfc2126DateTimeFormatter.java

package org.jboss.arquillian.drone.webdriver.utils;

import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeFormatterBuilder;
import java.time.format.SignStyle;
import java.util.HashMap;
import java.util.Map;

import static java.time.temporal.ChronoField.DAY_OF_MONTH;
import static java.time.temporal.ChronoField.DAY_OF_WEEK;
import static java.time.temporal.ChronoField.HOUR_OF_DAY;
import static java.time.temporal.ChronoField.MINUTE_OF_HOUR;
import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
import static java.time.temporal.ChronoField.SECOND_OF_MINUTE;
import static java.time.temporal.ChronoField.YEAR;

public class Rfc2126DateTimeFormatter {

    public static final DateTimeFormatter INSTANCE;

    static {
        // manually code maps to ensure correct data always used
        // (locale data can be changed by application code)
        Map<Long, String> dow = new HashMap<>();
        dow.put(1L, "Mon");
        dow.put(2L, "Tue");
        dow.put(3L, "Wed");
        dow.put(4L, "Thu");
        dow.put(5L, "Fri");
        dow.put(6L, "Sat");
        dow.put(7L, "Sun");
        Map<Long, String> moy = new HashMap<>();
        moy.put(1L, "Jan");
        moy.put(2L, "Feb");
        moy.put(3L, "Mar");
        moy.put(4L, "Apr");
        moy.put(5L, "May");
        moy.put(6L, "Jun");
        moy.put(7L, "Jul");
        moy.put(8L, "Aug");
        moy.put(9L, "Sep");
        moy.put(10L, "Oct");
        moy.put(11L, "Nov");
        moy.put(12L, "Dec");
        INSTANCE = new DateTimeFormatterBuilder()
            .parseCaseInsensitive()
            .parseLenient()
            .optionalStart()
            .appendText(DAY_OF_WEEK, dow)
            .appendLiteral(", ")
            .optionalEnd()
            .appendValue(DAY_OF_MONTH, 2, 2, SignStyle.NOT_NEGATIVE)
            .appendLiteral(' ')
            .appendText(MONTH_OF_YEAR, moy)
            .appendLiteral(' ')
            .appendValue(YEAR, 4)  // 2 digit year not handled
            .appendLiteral(' ')
            .appendValue(HOUR_OF_DAY, 2)
            .appendLiteral(':')
            .appendValue(MINUTE_OF_HOUR, 2)
            .optionalStart()
            .appendLiteral(':')
            .appendValue(SECOND_OF_MINUTE, 2)
            .optionalEnd()
            .appendLiteral(' ')
            .appendOffset("+HHMM", "GMT")  // should handle UT/Z/EST/EDT/CST/CDT/MST/MDT/PST/MDT
            .toFormatter();
    }
}