1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 * 19 */ 20 package org.apache.mina.http; 21 22 import java.text.DateFormat; 23 import java.text.ParseException; 24 import java.text.SimpleDateFormat; 25 import java.util.Calendar; 26 import java.util.Date; 27 import java.util.Locale; 28 import java.util.TimeZone; 29 import java.util.regex.Pattern; 30 31 /** 32 * 33 * @author <a href="http://mina.apache.org">Apache MINA Project</a> 34 */ 35 public class DateUtil { 36 /** A thread local is used to protect the DateFormat against concurrent access */ 37 private static final ThreadLocal<DateFormat> RFC_1123_FORMAT = new ThreadLocal<DateFormat>() { 38 /** 39 * Initialize the formatter 40 */ 41 protected DateFormat initialValue() { 42 DateFormat dateFormat = new SimpleDateFormat(RFC_1123_PATTERN, Locale.US); 43 TimeZone gmtZone = TimeZone.getTimeZone("GMT"); 44 dateFormat.setTimeZone(gmtZone); 45 46 return dateFormat; 47 } 48 }; 49 50 /** The format of an HTTP date */ 51 private static final String RFC_1123_PATTERN = "EEE, dd MMM yyyy HH:mm:ss zzz"; 52 53 /** Pattern to find digits only. */ 54 private static final Pattern DIGIT_PATTERN = Pattern.compile("^\\d+$"); 55 56 /** 57 * Returns the current date as String 58 * 59 * @return Current Date as String, in the format <i>EEE, dd MMM yyyy HH:mm:ss zzz</i> 60 */ 61 public static String getCurrentAsString() { 62 return RFC_1123_FORMAT.get().format(new Date()); 63 } 64 65 /** 66 * Translate a given date <code>String</code> in the <em>RFC 1123</em> 67 * format to a <code>long</code> representing the number of milliseconds 68 * since epoch. 69 * 70 * @param dateString a date <code>String</code> in the <em>RFC 1123</em> 71 * format. 72 * @return the parsed <code>Date</code> in milliseconds. 73 */ 74 private static long parseDateStringToMilliseconds(final String dateString) { 75 76 try { 77 return RFC_1123_FORMAT.get().parse(dateString).getTime(); 78 } catch (final ParseException e) { 79 return 0; 80 } 81 } 82 83 /** 84 * Parse a given date <code>String</code> to a <code>long</code> 85 * representation of the time. Where the provided value is all digits the 86 * value is returned as a <code>long</code>, otherwise attempt is made to 87 * parse the <code>String</code> as a <em>RFC 1123</em> date. 88 * 89 * @param dateValue the value to parse. 90 * @return the <code>long</code> value following parse, or zero where not 91 * successful. 92 */ 93 public static long parseToMilliseconds(final String dateValue) { 94 95 long ms = 0; 96 97 if (DIGIT_PATTERN.matcher(dateValue).matches()) { 98 ms = Long.parseLong(dateValue); 99 } else { 100 ms = parseDateStringToMilliseconds(dateValue); 101 } 102 103 return ms; 104 } 105 106 /** 107 * Converts a millisecond representation of a date to a 108 * <code>RFC 1123</code> formatted <code>String</code>. 109 * 110 * @param dateValue the <code>Date</code> represented as milliseconds. 111 * @return a <code>String</code> representation of the date. 112 */ 113 public static String parseToRFC1123(final long dateValue) { 114 final Calendar calendar = Calendar.getInstance(); 115 calendar.setTimeInMillis(dateValue); 116 117 return RFC_1123_FORMAT.get().format(calendar.getTime()); 118 } 119 120 /** 121 * Convert a given <code>Date</code> object to a <code>RFC 1123</code> 122 * formatted <code>String</code>. 123 * 124 * @param date the <code>Date</code> object to convert 125 * @return a <code>String</code> representation of the date. 126 */ 127 public static String getDateAsString(Date date) { 128 return RFC_1123_FORMAT.get().format(date); 129 } 130 }