Clean up following #6016

Motivation:

* DefaultHeaders from netty-codec has some duplicated logic for header date parsing
* Several classes keep on using deprecated HttpHeaderDateFormat

Modifications:

* Move HttpHeaderDateFormatter to netty-codec and rename it into HeaderDateFormatter
* Make DefaultHeaders use HeaderDateFormatter
* Replace HttpHeaderDateFormat usage with HeaderDateFormatter

Result:

Faster and more consistent code

codec-http/src/main/java/io/netty/handler/codec/http/CookieDecoder.java

@@ -18,13 +18,15 @@ package io.netty.handler.codec.http;
 import static io.netty.handler.codec.http.CookieUtil.firstInvalidCookieNameOctet;
 import static io.netty.handler.codec.http.CookieUtil.firstInvalidCookieValueOctet;
 import static io.netty.handler.codec.http.CookieUtil.unwrapValue;
+
+import io.netty.handler.codec.DateFormatter;
 import io.netty.handler.codec.http.cookie.CookieHeaderNames;
 import io.netty.util.internal.logging.InternalLogger;
 import io.netty.util.internal.logging.InternalLoggerFactory;
 
-import java.text.ParseException;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Date;
 import java.util.List;
 import java.util.Set;
 import java.util.TreeSet;
@@ -152,14 +154,10 @@ public final class CookieDecoder {
                 } else if (CookieHeaderNames.PATH.equalsIgnoreCase(name)) {
                     path = value;
                 } else if (CookieHeaderNames.EXPIRES.equalsIgnoreCase(name)) {
-                    try {
+                    Date date = DateFormatter.parseHttpDate(value);
-                        long maxAgeMillis =
+                    if (date != null) {
-                            HttpHeaderDateFormat.get().parse(value).getTime() -
+                        long maxAgeMillis = date.getTime() - System.currentTimeMillis();
-                            System.currentTimeMillis();
-
                         maxAge = maxAgeMillis / 1000 + (maxAgeMillis % 1000 != 0? 1 : 0);
-                    } catch (ParseException e) {
-                        // Ignore.
                     }
                 } else if (CookieHeaderNames.MAX_AGE.equalsIgnoreCase(name)) {
                     maxAge = Integer.parseInt(value);

codec-http/src/main/java/io/netty/handler/codec/http/DefaultHttpHeaders.java

@@ -16,6 +16,7 @@
 package io.netty.handler.codec.http;
 
 import io.netty.handler.codec.CharSequenceValueConverter;
+import io.netty.handler.codec.DateFormatter;
 import io.netty.handler.codec.DefaultHeaders;
 import io.netty.handler.codec.DefaultHeaders.NameValidator;
 import io.netty.handler.codec.DefaultHeadersImpl;
@@ -391,10 +392,10 @@ public class DefaultHttpHeaders extends HttpHeaders {
                 return (CharSequence) value;
             }
             if (value instanceof Date) {
-                return HttpHeaderDateFormat.get().format((Date) value);
+                return DateFormatter.format((Date) value);
             }
             if (value instanceof Calendar) {
-                return HttpHeaderDateFormat.get().format(((Calendar) value).getTime());
+                return DateFormatter.format(((Calendar) value).getTime());
             }
             return value.toString();
         }

codec-http/src/main/java/io/netty/handler/codec/http/HttpHeaderDateFormat.java

@@ -16,6 +16,7 @@
 package io.netty.handler.codec.http;
 
 import io.netty.util.concurrent.FastThreadLocal;
+import io.netty.handler.codec.DateFormatter;
 
 import java.text.ParsePosition;
 import java.text.SimpleDateFormat;
@@ -32,7 +33,7 @@ import java.util.TimeZone;
  * <li>Sunday, 06-Nov-94 08:49:37 GMT: obsolete specification</li>
  * <li>Sun Nov  6 08:49:37 1994: obsolete specification</li>
  * </ul>
- * @deprecated Use {@link HttpHeaderDateFormatter} instead
+ * @deprecated Use {@link DateFormatter} instead
  */
 @Deprecated
 public final class HttpHeaderDateFormat extends SimpleDateFormat {

codec-http/src/main/java/io/netty/handler/codec/http/HttpHeaders.java

@@ -17,6 +17,7 @@ package io.netty.handler.codec.http;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufUtil;
+import io.netty.handler.codec.DateFormatter;
 import io.netty.handler.codec.Headers;
 import io.netty.util.AsciiString;
 
@@ -839,7 +840,11 @@ public abstract class HttpHeaders implements Iterable<Map.Entry<String, String>>
         if (value == null) {
             throw new ParseException("header not found: " + name, 0);
         }
-        return HttpHeaderDateFormat.get().parse(value);
+        Date date = DateFormatter.parseHttpDate(value);
+        if (date == null) {
+            throw new ParseException("header can't be parsed into a Date: " + value, 0);
+        }
+        return date;
     }
 
     /**
@@ -865,15 +870,8 @@ public abstract class HttpHeaders implements Iterable<Map.Entry<String, String>>
     @Deprecated
     public static Date getDateHeader(HttpMessage message, CharSequence name, Date defaultValue) {
         final String value = getHeader(message, name);
-        if (value == null) {
+        Date date = DateFormatter.parseHttpDate(value);
-            return defaultValue;
+        return date != null ? date : defaultValue;
-        }
-
-        try {
-            return HttpHeaderDateFormat.get().parse(value);
-        } catch (ParseException ignored) {
-            return defaultValue;
-        }
     }
 
     /**
@@ -897,7 +895,7 @@ public abstract class HttpHeaders implements Iterable<Map.Entry<String, String>>
     @Deprecated
     public static void setDateHeader(HttpMessage message, CharSequence name, Date value) {
         if (value != null) {
-            message.headers().set(name, HttpHeaderDateFormat.get().format(value));
+            message.headers().set(name, DateFormatter.format(value));
         } else {
             message.headers().set(name, null);
         }

codec-http/src/main/java/io/netty/handler/codec/http/cookie/ClientCookieDecoder.java

@@ -15,7 +15,7 @@
  */
 package io.netty.handler.codec.http.cookie;
 
-import io.netty.handler.codec.http.HttpHeaderDateFormatter;
+import io.netty.handler.codec.DateFormatter;
 
 import java.util.Date;
 
@@ -168,7 +168,7 @@ public final class ClientCookieDecoder extends CookieDecoder {
             if (maxAge != Long.MIN_VALUE) {
                 return maxAge;
             } else if (isValueDefined(expiresStart, expiresEnd)) {
-                Date expiresDate = HttpHeaderDateFormatter.parse(header, expiresStart, expiresEnd);
+                Date expiresDate = DateFormatter.parseHttpDate(header, expiresStart, expiresEnd);
                 if (expiresDate != null) {
                     long maxAgeMillis = expiresDate.getTime() - System.currentTimeMillis();
                     return maxAgeMillis / 1000 + (maxAgeMillis % 1000 != 0 ? 1 : 0);

codec-http/src/main/java/io/netty/handler/codec/http/cookie/ServerCookieEncoder.java

@@ -21,7 +21,7 @@ import static io.netty.handler.codec.http.cookie.CookieUtil.stringBuilder;
 import static io.netty.handler.codec.http.cookie.CookieUtil.stripTrailingSeparator;
 import static io.netty.util.internal.ObjectUtil.checkNotNull;
 
-import io.netty.handler.codec.http.HttpHeaderDateFormatter;
+import io.netty.handler.codec.DateFormatter;
 import io.netty.handler.codec.http.HttpConstants;
 import io.netty.handler.codec.http.HttpRequest;
 
@@ -106,7 +106,7 @@ public final class ServerCookieEncoder extends CookieEncoder {
             Date expires = new Date(cookie.maxAge() * 1000 + System.currentTimeMillis());
             buf.append(CookieHeaderNames.EXPIRES);
             buf.append((char) HttpConstants.EQUALS);
-            HttpHeaderDateFormatter.append(expires, buf);
+            DateFormatter.append(expires, buf);
             buf.append((char) HttpConstants.SEMICOLON);
             buf.append((char) HttpConstants.SP);
         }

codec-http/src/test/java/io/netty/handler/codec/http/HttpHeaderDateFormatterTest.java

@@ -1,114 +0,0 @@
-/*
- * Copyright 2016 The Netty Project
- *
- * The Netty Project licenses this file to you 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
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations
- * under the License.
- */
-package io.netty.handler.codec.http;
-
-import org.junit.Test;
-
-import java.util.Date;
-
-import static org.junit.Assert.*;
-import static io.netty.handler.codec.http.HttpHeaderDateFormatter.*;
-
-public class HttpHeaderDateFormatterTest {
-    /**
-     * This date is set at "06 Nov 1994 08:49:37 GMT", from
-     * <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html">examples in RFC documentation</a>
-     */
-    private static final long TIMESTAMP = 784111777000L;
-    private static final Date DATE = new Date(TIMESTAMP);
-
-    @Test
-    public void testParseWithSingleDigitDay() {
-        assertEquals(DATE, parse("Sun, 6 Nov 1994 08:49:37 GMT"));
-    }
-
-    @Test
-    public void testParseWithDoubleDigitDay() {
-        assertEquals(DATE, parse("Sun, 06 Nov 1994 08:49:37 GMT"));
-    }
-
-    @Test
-    public void testParseWithDashSeparatorSingleDigitDay() {
-        assertEquals(DATE, parse("Sunday, 06-Nov-94 08:49:37 GMT"));
-    }
-
-    @Test
-    public void testParseWithSingleDoubleDigitDay() {
-        assertEquals(DATE, parse("Sunday, 6-Nov-94 08:49:37 GMT"));
-    }
-
-    @Test
-    public void testParseWithoutGMT() {
-        assertEquals(DATE, parse("Sun Nov 6 08:49:37 1994"));
-    }
-
-    @Test
-    public void testParseWithFunkyTimezone() {
-        assertEquals(DATE, parse("Sun Nov 6 08:49:37 1994 -0000"));
-    }
-
-    @Test
-    public void testParseWithSingleDigitHourMinutesAndSecond() {
-        assertEquals(DATE, parse("Sunday, 6-Nov-94 8:49:37 GMT"));
-    }
-
-    @Test
-    public void testParseWithSingleDigitTime() {
-        assertEquals(DATE, parse("Sunday, 6 Nov 1994 8:49:37 GMT"));
-
-        Date _08_09_37 = new Date(TIMESTAMP - 40 * 60 * 1000);
-        assertEquals(_08_09_37, parse("Sunday, 6 Nov 1994 8:9:37 GMT"));
-        assertEquals(_08_09_37, parse("Sunday, 6 Nov 1994 8:09:37 GMT"));
-
-        Date _08_09_07 = new Date(TIMESTAMP - (40 * 60 + 30) * 1000);
-        assertEquals(_08_09_07, parse("Sunday, 6 Nov 1994 8:9:7 GMT"));
-        assertEquals(_08_09_07, parse("Sunday, 6 Nov 1994 8:9:07 GMT"));
-    }
-
-    @Test
-    public void testParseMidnight() {
-        assertEquals(new Date(784080000000L), parse("Sunday, 6 Nov 1994 00:00:00 GMT"));
-    }
-
-    @Test
-    public void testParseInvalidInput() {
-        // missing field
-        assertNull(parse("Sun, Nov 1994 08:49:37 GMT"));
-        assertNull(parse("Sun, 6 1994 08:49:37 GMT"));
-        assertNull(parse("Sun, 6 Nov 08:49:37 GMT"));
-        assertNull(parse("Sun, 6 Nov 1994 :49:37 GMT"));
-        assertNull(parse("Sun, 6 Nov 1994 49:37 GMT"));
-        assertNull(parse("Sun, 6 Nov 1994 08::37 GMT"));
-        assertNull(parse("Sun, 6 Nov 1994 08:37 GMT"));
-        assertNull(parse("Sun, 6 Nov 1994 08:49: GMT"));
-        assertNull(parse("Sun, 6 Nov 1994 08:49 GMT"));
-        //invalid value
-        assertNull(parse("Sun, 6 FOO 1994 08:49:37 GMT"));
-        assertNull(parse("Sun, 36 Nov 1994 08:49:37 GMT"));
-        assertNull(parse("Sun, 6 Nov 1994 28:49:37 GMT"));
-        assertNull(parse("Sun, 6 Nov 1994 08:69:37 GMT"));
-        assertNull(parse("Sun, 6 Nov 1994 08:49:67 GMT"));
-        //wrong number of digits in timestamp
-        assertNull(parse("Sunday, 6 Nov 1994 0:0:000 GMT"));
-        assertNull(parse("Sunday, 6 Nov 1994 0:000:0 GMT"));
-        assertNull(parse("Sunday, 6 Nov 1994 000:0:0 GMT"));
-    }
-
-    @Test
-    public void testFormat() {
-        assertEquals("Sun, 6 Nov 1994 08:49:37 GMT", format(DATE));
-    }
-}

codec-http/src/test/java/io/netty/handler/codec/http/cookie/ClientCookieDecoderTest.java

@@ -15,7 +15,7 @@
  */
 package io.netty.handler.codec.http.cookie;
 
-import io.netty.handler.codec.http.HttpHeaderDateFormatter;
+import io.netty.handler.codec.DateFormatter;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -30,26 +30,18 @@ import static org.junit.Assert.*;
 public class ClientCookieDecoderTest {
     @Test
     public void testDecodingSingleCookieV0() {
-        String cookieString = "myCookie=myValue;expires=XXX;path=/apathsomewhere;domain=.adomainsomewhere;secure;";
+        String cookieString = "myCookie=myValue;expires="
-        cookieString = cookieString.replace("XXX",
+                + DateFormatter.format(new Date(System.currentTimeMillis() + 50000))
-                HttpHeaderDateFormatter.format(new Date(System.currentTimeMillis() + 50000)));
+                + ";path=/apathsomewhere;domain=.adomainsomewhere;secure;";
 
         Cookie cookie = ClientCookieDecoder.STRICT.decode(cookieString);
         assertNotNull(cookie);
         assertEquals("myValue", cookie.value());
         assertEquals(".adomainsomewhere", cookie.domain());
-
+        assertNotEquals("maxAge should be defined when parsing cookie " + cookieString,
-        boolean fail = true;
+                Long.MIN_VALUE, cookie.maxAge());
-        for (int i = 40; i <= 60; i++) {
+        assertTrue("maxAge should be about 50ms when parsing cookie " + cookieString,
-            if (cookie.maxAge() == i) {
+                cookie.maxAge() >= 40 && cookie.maxAge() <= 60);
-                fail = false;
-                break;
-            }
-        }
-        if (fail) {
-            fail("expected: 50, actual: " + cookie.maxAge());
-        }
-
         assertEquals("/apathsomewhere", cookie.path());
         assertTrue(cookie.isSecure());
     }

codec-http/src/test/java/io/netty/handler/codec/http/cookie/ServerCookieDecoderTest.java

@@ -17,9 +17,6 @@ package io.netty.handler.codec.http.cookie;
 
 import org.junit.Test;
 
-import io.netty.handler.codec.http.HttpHeaderDateFormat;
-
-import java.util.Date;
 import java.util.Iterator;
 import java.util.Set;
 
@@ -29,9 +26,6 @@ public class ServerCookieDecoderTest {
     @Test
     public void testDecodingSingleCookie() {
         String cookieString = "myCookie=myValue";
-        cookieString = cookieString.replace("XXX",
-                HttpHeaderDateFormat.get().format(new Date(System.currentTimeMillis() + 50000)));
-
         Set<Cookie> cookies = ServerCookieDecoder.STRICT.decode(cookieString);
         assertEquals(1, cookies.size());
         Cookie cookie = cookies.iterator().next();

codec-http/src/test/java/io/netty/handler/codec/http/cookie/ServerCookieEncoderTest.java

@@ -19,7 +19,7 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
-import io.netty.handler.codec.http.HttpHeaderDateFormat;
+import io.netty.handler.codec.DateFormatter;
 
 import java.text.ParseException;
 import java.util.ArrayList;
@@ -51,7 +51,7 @@ public class ServerCookieEncoderTest {
 
         Matcher matcher = Pattern.compile(result).matcher(encodedCookie);
         assertTrue(matcher.find());
-        Date expiresDate = HttpHeaderDateFormat.get().parse(matcher.group(1));
+        Date expiresDate = DateFormatter.parseHttpDate(matcher.group(1));
         long diff = (expiresDate.getTime() - System.currentTimeMillis()) / 1000;
         // 2 secs should be fine
         assertTrue(Math.abs(diff - maxAge) <= 2);

codec/src/main/java/io/netty/handler/codec/CharSequenceValueConverter.java

@@ -14,11 +14,11 @@
  */
 package io.netty.handler.codec;
 
-import io.netty.handler.codec.DefaultHeaders.HeaderDateFormat;
 import io.netty.util.AsciiString;
 import io.netty.util.internal.PlatformDependent;
 
 import java.text.ParseException;
+import java.util.Date;
 
 /**
  * Converts to/from native types, general {@link Object}, and {@link CharSequence}s.
@@ -126,12 +126,12 @@ public class CharSequenceValueConverter implements ValueConverter<CharSequence>
 
     @Override
     public long convertToTimeMillis(CharSequence value) {
-        try {
+        Date date = DateFormatter.parseHttpDate(value);
-            return HeaderDateFormat.get().parse(value.toString());
+        if (date == null) {
-        } catch (ParseException e) {
+            PlatformDependent.throwException(new ParseException("header can't be parsed into a Date: " + value, 0));
-            PlatformDependent.throwException(e);
             return 0;
         }
+        return date.getTime();
     }
 
     @Override

codec/src/main/java/io/netty/handler/codec/DateFormatter.java

@@ -13,7 +13,7 @@
  * License for the specific language governing permissions and limitations
  * under the License.
  */
-package io.netty.handler.codec.http;
+package io.netty.handler.codec;
 
 import static io.netty.util.internal.ObjectUtil.checkNotNull;
 
@@ -43,7 +43,7 @@ import java.util.TimeZone;
  * @see <a href="https://tools.ietf.org/html/rfc6265#section-5.1.1">RFC6265</a> for the parsing side
  * @see <a href="https://tools.ietf.org/html/rfc1123#page-55">RFC1123</a> for the encoding side.
  */
-public final class HttpHeaderDateFormatter {
+public final class DateFormatter {
 
     private static final BitSet DELIMITERS = new BitSet();
     static {
@@ -68,11 +68,11 @@ public final class HttpHeaderDateFormatter {
     private static final String[] CALENDAR_MONTH_TO_SHORT_NAME =
             new String[]{"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
 
-    private static final FastThreadLocal<HttpHeaderDateFormatter> INSTANCES =
+    private static final FastThreadLocal<DateFormatter> INSTANCES =
-            new FastThreadLocal<HttpHeaderDateFormatter>() {
+            new FastThreadLocal<DateFormatter>() {
                 @Override
-                protected HttpHeaderDateFormatter initialValue() {
+                protected DateFormatter initialValue() {
-                    return new HttpHeaderDateFormatter();
+                    return new DateFormatter();
                 }
             };
 
@@ -81,8 +81,8 @@ public final class HttpHeaderDateFormatter {
      * @param txt text to parse
      * @return a {@link Date}, or null if text couldn't be parsed
      */
-    public static Date parse(CharSequence txt) {
+    public static Date parseHttpDate(CharSequence txt) {
-        return parse(txt, 0, txt.length());
+        return parseHttpDate(txt, 0, txt.length());
     }
 
     /**
@@ -92,7 +92,7 @@ public final class HttpHeaderDateFormatter {
      * @param end the end index inside <code>txt</code>
      * @return a {@link Date}, or null if text couldn't be parsed
      */
-    public static Date parse(CharSequence txt, int start, int end) {
+    public static Date parseHttpDate(CharSequence txt, int start, int end) {
         int length = end - start;
         if (length == 0) {
             return null;
@@ -124,8 +124,8 @@ public final class HttpHeaderDateFormatter {
         return formatter().append0(checkNotNull(date, "date"), checkNotNull(sb, "sb"));
     }
 
-    private static HttpHeaderDateFormatter formatter() {
+    private static DateFormatter formatter() {
-        HttpHeaderDateFormatter formatter = INSTANCES.get();
+        DateFormatter formatter = INSTANCES.get();
         formatter.reset();
         return formatter;
     }
@@ -156,7 +156,7 @@ public final class HttpHeaderDateFormatter {
     private boolean yearFound;
     private int year;
 
-    private HttpHeaderDateFormatter() {
+    private DateFormatter() {
         reset();
     }
 
@@ -171,7 +171,7 @@ public final class HttpHeaderDateFormatter {
         month = -1;
         yearFound = false;
         year = -1;
-        cal.set(Calendar.MILLISECOND, 0);
+        cal.clear();
         sb.setLength(0);
     }
 

codec/src/main/java/io/netty/handler/codec/DefaultHeaders.java

@@ -15,24 +15,17 @@
 package io.netty.handler.codec;
 
 import io.netty.util.HashingStrategy;
-import io.netty.util.concurrent.FastThreadLocal;
 
-import java.text.DateFormat;
-import java.text.ParseException;
-import java.text.SimpleDateFormat;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.Date;
 import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;
-import java.util.Locale;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.NoSuchElementException;
 import java.util.Set;
-import java.util.TimeZone;
 
 import static io.netty.util.HashingStrategy.JAVA_HASHER;
 import static io.netty.util.internal.MathUtil.findNextPositivePowerOfTwo;
@@ -960,77 +953,6 @@ public class DefaultHeaders<K, V, T extends Headers<K, V, T>> implements Headers
         return (T) this;
     }
 
-    /**
-     * This {@link DateFormat} decodes 3 formats of {@link Date}.
-     *
-     * <ul>
-     * <li>Sun, 06 Nov 1994 08:49:37 GMT: standard specification, the only one with valid generation</li>
-     * <li>Sun, 06 Nov 1994 08:49:37 GMT: obsolete specification</li>
-     * <li>Sun Nov 6 08:49:37 1994: obsolete specification</li>
-     * </ul>
-     */
-    public static final class HeaderDateFormat {
-        private static final FastThreadLocal<HeaderDateFormat> dateFormatThreadLocal =
-                new FastThreadLocal<HeaderDateFormat>() {
-                    @Override
-                    protected HeaderDateFormat initialValue() {
-                        return new HeaderDateFormat();
-                    }
-                };
-
-        static HeaderDateFormat get() {
-            return dateFormatThreadLocal.get();
-        }
-
-        /**
-         * Standard date format:
-         *
-         * <pre>
-         * Sun, 06 Nov 1994 08:49:37 GMT -> E, d MMM yyyy HH:mm:ss z
-         * </pre>
-         */
-        private final DateFormat dateFormat1 = new SimpleDateFormat("E, dd MMM yyyy HH:mm:ss z", Locale.ENGLISH);
-
-        /**
-         * First obsolete format:
-         *
-         * <pre>
-         * Sunday, 06-Nov-94 08:49:37 GMT -> E, d-MMM-y HH:mm:ss z
-         * </pre>
-         */
-        private final DateFormat dateFormat2 = new SimpleDateFormat("E, dd-MMM-yy HH:mm:ss z", Locale.ENGLISH);
-
-        /**
-         * Second obsolete format
-         *
-         * <pre>
-         * Sun Nov 6 08:49:37 1994 -> EEE, MMM d HH:mm:ss yyyy
-         * </pre>
-         */
-        private final DateFormat dateFormat3 = new SimpleDateFormat("E MMM d HH:mm:ss yyyy", Locale.ENGLISH);
-
-        private HeaderDateFormat() {
-            TimeZone tz = TimeZone.getTimeZone("GMT");
-            dateFormat1.setTimeZone(tz);
-            dateFormat2.setTimeZone(tz);
-            dateFormat3.setTimeZone(tz);
-        }
-
-        long parse(String text) throws ParseException {
-            Date date = dateFormat1.parse(text);
-            if (date == null) {
-                date = dateFormat2.parse(text);
-            }
-            if (date == null) {
-                date = dateFormat3.parse(text);
-            }
-            if (date == null) {
-                throw new ParseException(text, 0);
-            }
-            return date.getTime();
-        }
-    }
-
     private final class HeaderIterator implements Iterator<Map.Entry<K, V>> {
         private HeaderEntry<K, V> current = head;
 

codec/src/test/java/io/netty/handler/codec/DateFormatterTest.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright 2016 The Netty Project
+ *
+ * The Netty Project licenses this file to you 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package io.netty.handler.codec;
+
+import org.junit.Test;
+
+import java.util.Date;
+
+import static org.junit.Assert.*;
+import static io.netty.handler.codec.DateFormatter.*;
+
+public class DateFormatterTest {
+    /**
+     * This date is set at "06 Nov 1994 08:49:37 GMT", from
+     * <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html">examples in RFC documentation</a>
+     */
+    private static final long TIMESTAMP = 784111777000L;
+    private static final Date DATE = new Date(TIMESTAMP);
+
+    @Test
+    public void testParseWithSingleDigitDay() {
+        assertEquals(DATE, parseHttpDate("Sun, 6 Nov 1994 08:49:37 GMT"));
+    }
+
+    @Test
+    public void testParseWithDoubleDigitDay() {
+        assertEquals(DATE, parseHttpDate("Sun, 06 Nov 1994 08:49:37 GMT"));
+    }
+
+    @Test
+    public void testParseWithDashSeparatorSingleDigitDay() {
+        assertEquals(DATE, parseHttpDate("Sunday, 06-Nov-94 08:49:37 GMT"));
+    }
+
+    @Test
+    public void testParseWithSingleDoubleDigitDay() {
+        assertEquals(DATE, parseHttpDate("Sunday, 6-Nov-94 08:49:37 GMT"));
+    }
+
+    @Test
+    public void testParseWithoutGMT() {
+        assertEquals(DATE, parseHttpDate("Sun Nov 6 08:49:37 1994"));
+    }
+
+    @Test
+    public void testParseWithFunkyTimezone() {
+        assertEquals(DATE, parseHttpDate("Sun Nov 6 08:49:37 1994 -0000"));
+    }
+
+    @Test
+    public void testParseWithSingleDigitHourMinutesAndSecond() {
+        assertEquals(DATE, parseHttpDate("Sunday, 6-Nov-94 8:49:37 GMT"));
+    }
+
+    @Test
+    public void testParseWithSingleDigitTime() {
+        assertEquals(DATE, parseHttpDate("Sunday, 6 Nov 1994 8:49:37 GMT"));
+
+        Date _08_09_37 = new Date(TIMESTAMP - 40 * 60 * 1000);
+        assertEquals(_08_09_37, parseHttpDate("Sunday, 6 Nov 1994 8:9:37 GMT"));
+        assertEquals(_08_09_37, parseHttpDate("Sunday, 6 Nov 1994 8:09:37 GMT"));
+
+        Date _08_09_07 = new Date(TIMESTAMP - (40 * 60 + 30) * 1000);
+        assertEquals(_08_09_07, parseHttpDate("Sunday, 6 Nov 1994 8:9:7 GMT"));
+        assertEquals(_08_09_07, parseHttpDate("Sunday, 6 Nov 1994 8:9:07 GMT"));
+    }
+
+    @Test
+    public void testParseMidnight() {
+        assertEquals(new Date(784080000000L), parseHttpDate("Sunday, 6 Nov 1994 00:00:00 GMT"));
+    }
+
+    @Test
+    public void testParseInvalidInput() {
+        // missing field
+        assertNull(parseHttpDate("Sun, Nov 1994 08:49:37 GMT"));
+        assertNull(parseHttpDate("Sun, 6 1994 08:49:37 GMT"));
+        assertNull(parseHttpDate("Sun, 6 Nov 08:49:37 GMT"));
+        assertNull(parseHttpDate("Sun, 6 Nov 1994 :49:37 GMT"));
+        assertNull(parseHttpDate("Sun, 6 Nov 1994 49:37 GMT"));
+        assertNull(parseHttpDate("Sun, 6 Nov 1994 08::37 GMT"));
+        assertNull(parseHttpDate("Sun, 6 Nov 1994 08:37 GMT"));
+        assertNull(parseHttpDate("Sun, 6 Nov 1994 08:49: GMT"));
+        assertNull(parseHttpDate("Sun, 6 Nov 1994 08:49 GMT"));
+        //invalid value
+        assertNull(parseHttpDate("Sun, 6 FOO 1994 08:49:37 GMT"));
+        assertNull(parseHttpDate("Sun, 36 Nov 1994 08:49:37 GMT"));
+        assertNull(parseHttpDate("Sun, 6 Nov 1994 28:49:37 GMT"));
+        assertNull(parseHttpDate("Sun, 6 Nov 1994 08:69:37 GMT"));
+        assertNull(parseHttpDate("Sun, 6 Nov 1994 08:49:67 GMT"));
+        //wrong number of digits in timestamp
+        assertNull(parseHttpDate("Sunday, 6 Nov 1994 0:0:000 GMT"));
+        assertNull(parseHttpDate("Sunday, 6 Nov 1994 0:000:0 GMT"));
+        assertNull(parseHttpDate("Sunday, 6 Nov 1994 000:0:0 GMT"));
+    }
+
+    @Test
+    public void testFormat() {
+        assertEquals("Sun, 6 Nov 1994 08:49:37 GMT", format(DATE));
+    }
+}

microbench/src/main/java/io/netty/handler/codec/DateFormatterBenchmark.java

@@ -13,10 +13,9 @@
  * License for the specific language governing permissions and limitations
  * under the License.
  */
-package io.netty.microbench.http;
+package io.netty.handler.codec;
 
 import io.netty.handler.codec.http.HttpHeaderDateFormat;
-import io.netty.handler.codec.http.HttpHeaderDateFormatter;
 import org.openjdk.jmh.annotations.Benchmark;
 import org.openjdk.jmh.annotations.OutputTimeUnit;
 
@@ -24,14 +23,14 @@ import java.util.Date;
 import java.util.concurrent.TimeUnit;
 
 @OutputTimeUnit(TimeUnit.SECONDS)
-public class HttpHeaderDateFormatterBenchmark {
+public class DateFormatterBenchmark {
 
     private static final String DATE_STRING = "Sun, 27 Nov 2016 19:18:46 GMT";
     private static final Date DATE = new Date(784111777000L);
 
     @Benchmark
     public Date parseHttpHeaderDateFormatter() {
-        return HttpHeaderDateFormatter.parse(DATE_STRING);
+        return DateFormatter.parseHttpDate(DATE_STRING);
     }
 
     @Benchmark
@@ -41,7 +40,7 @@ public class HttpHeaderDateFormatterBenchmark {
 
     @Benchmark
     public String formatHttpHeaderDateFormatter() {
-        return HttpHeaderDateFormatter.format(DATE);
+        return DateFormatter.format(DATE);
     }
 
     @Benchmark