| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF 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 org.apache.nutch.net.protocols; |
| |
| import java.util.Calendar; |
| import java.util.Date; |
| import java.util.Locale; |
| import java.util.TimeZone; |
| import java.text.SimpleDateFormat; |
| import java.text.ParseException; |
| |
| /** |
| * Parse and format HTTP dates in HTTP headers, e.g., used to fill the |
| * "If-Modified-Since" request header field. |
| * |
| * HTTP dates use Greenwich Mean Time (GMT) as time zone and a date format like: |
| * |
| * <pre> |
| * Sun, 06 Nov 1994 08:49:37 GMT |
| * </pre> |
| * |
| * See <a href= |
| * "https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.3.1">sec. 3.3.1 |
| * in RFC 2616</a> and |
| * <a href="https://tools.ietf.org/html/rfc7231#section-7.1.1.1">sec. 7.1.1.1 in |
| * RFC 7231</a>. |
| */ |
| public class HttpDateFormat { |
| |
| protected static SimpleDateFormat format = new SimpleDateFormat( |
| "EEE, dd MMM yyyy HH:mm:ss zzz", Locale.US); |
| |
| protected static TimeZone gmt = TimeZone.getTimeZone("GMT"); |
| |
| /** |
| * HTTP date uses TimeZone GMT |
| */ |
| static { |
| format.setTimeZone(gmt); |
| } |
| |
| /** |
| * Get the HTTP format of the specified date. |
| */ |
| public static String toString(Date date) { |
| String string; |
| synchronized (format) { |
| string = format.format(date); |
| } |
| return string; |
| } |
| |
| public static String toString(Calendar cal) { |
| String string; |
| synchronized (format) { |
| string = format.format(cal.getTime()); |
| } |
| return string; |
| } |
| |
| public static String toString(long time) { |
| String string; |
| synchronized (format) { |
| string = format.format(new Date(time)); |
| } |
| return string; |
| } |
| |
| public static Date toDate(String dateString) throws ParseException { |
| Date date; |
| synchronized (format) { |
| date = format.parse(dateString); |
| format.setTimeZone(gmt); |
| } |
| return date; |
| } |
| |
| public static long toLong(String dateString) throws ParseException { |
| long time; |
| synchronized (format) { |
| time = format.parse(dateString).getTime(); |
| format.setTimeZone(gmt); |
| } |
| return time; |
| } |
| |
| public static void main(String[] args) throws Exception { |
| Date now = new Date(System.currentTimeMillis()); |
| |
| String string = HttpDateFormat.toString(now); |
| |
| long time = HttpDateFormat.toLong(string); |
| |
| System.out.println(string); |
| System.out.println(HttpDateFormat.toString(time)); |
| } |
| |
| } |