com.undefinedlabs.scope.deps.okhttp3.internal.http.HttpDate Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of scope-deps Show documentation
Scope is a APM for tests to give engineering teams unprecedented visibility into their CI process to quickly identify, troubleshoot and fix failed builds. This artifact contains dependencies for Scope.
There is a newer version: 0.14.0-beta.2
Show newest version
package com.undefinedlabs.scope.deps.okhttp3.internal.http;

import java.text.DateFormat;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

import static com.undefinedlabs.scope.deps.okhttp3.internal.Util.UTC;

public final class HttpDate {
    /** The last four-digit year: "Fri, 31 Dec 9999 23:59:59 GMT". */
    public static final long MAX_DATE = 253402300799999L;

    /**
     * Most websites serve cookies in the blessed format. Eagerly create the parser to ensure such
     * cookies are on the fast path.
     */
    private static final ThreadLocal STANDARD_DATE_FORMAT =
            new ThreadLocal() {
                @Override protected DateFormat initialValue() {
                    // RFC 2616 specified: RFC 822, updated by RFC 1123 format with fixed GMT.
                    DateFormat rfc1123 = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss 'GMT'", Locale.US);
                    rfc1123.setLenient(false);
                    rfc1123.setTimeZone(UTC);
                    return rfc1123;
                }
            };

    /** If we fail to parse a date in a non-standard format, try each of these formats in sequence. */
    private static final String[] BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS = new String[] {
            // HTTP formats required by RFC2616 but with any timezone.
            "EEE, dd MMM yyyy HH:mm:ss zzz", // RFC 822, updated by RFC 1123 with any TZ
            "EEEE, dd-MMM-yy HH:mm:ss zzz", // RFC 850, obsoleted by RFC 1036 with any TZ.
            "EEE MMM d HH:mm:ss yyyy", // ANSI C's asctime() format
            // Alternative formats.
            "EEE, dd-MMM-yyyy HH:mm:ss z",
            "EEE, dd-MMM-yyyy HH-mm-ss z",
            "EEE, dd MMM yy HH:mm:ss z",
            "EEE dd-MMM-yyyy HH:mm:ss z",
            "EEE dd MMM yyyy HH:mm:ss z",
            "EEE dd-MMM-yyyy HH-mm-ss z",
            "EEE dd-MMM-yy HH:mm:ss z",
            "EEE dd MMM yy HH:mm:ss z",
            "EEE,dd-MMM-yy HH:mm:ss z",
            "EEE,dd-MMM-yyyy HH:mm:ss z",
            "EEE, dd-MM-yyyy HH:mm:ss z",

            /* RI bug 6641315 claims a cookie of this format was once served by www.yahoo.com */
            "EEE MMM d yyyy HH:mm:ss z",
    };

    private static final DateFormat[] BROWSER_COMPATIBLE_DATE_FORMATS =
            new DateFormat[BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS.length];

    /** Returns the date for {@code value}. Returns null if the value couldn't be parsed. */
    public static Date parse(String value) {
        if (value.length() == 0) {
            return null;
        }

        ParsePosition position = new ParsePosition(0);
        Date result = STANDARD_DATE_FORMAT.get().parse(value, position);
        if (position.getIndex() == value.length()) {
            // STANDARD_DATE_FORMAT must match exactly; all text must be consumed, e.g. no ignored
            // non-standard trailing "+01:00". Those cases are covered below.
            return result;
        }
        synchronized (BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS) {
            for (int i = 0, count = BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS.length; i < count; i++) {
                DateFormat format = BROWSER_COMPATIBLE_DATE_FORMATS[i];
                if (format == null) {
                    format = new SimpleDateFormat(BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS[i], Locale.US);
                    // Set the timezone to use when interpreting formats that don't have a timezone. GMT is
                    // specified by RFC 2616.
                    format.setTimeZone(UTC);
                    BROWSER_COMPATIBLE_DATE_FORMATS[i] = format;
                }
                position.setIndex(0);
                result = format.parse(value, position);
                if (position.getIndex() != 0) {
                    // Something was parsed. It's possible the entire string was not consumed but we ignore
                    // that. If any of the BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS ended in "'GMT'" we'd have
                    // to also check that position.getIndex() == value.length() otherwise parsing might have
                    // terminated early, ignoring things like "+01:00". Leaving this as != 0 means that any
                    // trailing junk is ignored.
                    return result;
                }
            }
        }
        return null;
    }

    /** Returns the string for {@code value}. */
    public static String format(Date value) {
        return STANDARD_DATE_FORMAT.get().format(value);
    }

    private HttpDate() {
    }
}