001// *************************************************************************************************************************** 002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * 003// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * 004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance * 005// * with the License. You may obtain a copy of the License at * 006// * * 007// * http://www.apache.org/licenses/LICENSE-2.0 * 008// * * 009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an * 010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * 011// * specific language governing permissions and limitations under the License. * 012// *************************************************************************************************************************** 013package org.apache.juneau.http; 014 015import static org.apache.juneau.internal.StringUtils.*; 016 017import org.apache.juneau.http.annotation.*; 018import org.apache.juneau.internal.*; 019 020/** 021 * Represents a parsed <l>Retry-After</l> HTTP response header. 022 * 023 * <p> 024 * If an entity is temporarily unavailable, this instructs the client to try again later. 025 * Value could be a specified period of time (in seconds) or a HTTP-date. 026 * 027 * <h5 class='figure'>Example</h5> 028 * <p class='bcode w800'> 029 * Retry-After: 120 030 * Retry-After: Fri, 07 Nov 2014 23:59:59 GMT 031 * </p> 032 * 033 * <h5 class='topic'>RFC2616 Specification</h5> 034 * 035 * The Retry-After response-header field can be used with a 503 (Service Unavailable) response to indicate how long the 036 * service is expected to be unavailable to the requesting client. 037 * This field MAY also be used with any 3xx (Redirection) response to indicate the minimum time the user-agent is asked 038 * wait before issuing the redirected request. 039 * The value of this field can be either an HTTP-date or an integer number of seconds (in decimal) after the time of the 040 * response. 041 * 042 * <p class='bcode w800'> 043 * Retry-After = "Retry-After" ":" ( HTTP-date | delta-seconds ) 044 * </p> 045 * 046 * <p> 047 * Two examples of its use are 048 * <p class='bcode w800'> 049 * Retry-After: Fri, 31 Dec 1999 23:59:59 GMT 050 * Retry-After: 120 051 * </p> 052 * 053 * <p> 054 * In the latter example, the delay is 2 minutes. 055 * 056 * <h5 class='section'>See Also:</h5> 057 * <ul class='doctree'> 058 * <li class='extlink'>{@doc RFC2616} 059 * </ul> 060 */ 061@Header("Retry-After") 062public final class RetryAfter extends HeaderString { 063 064 /** 065 * Returns a parsed <code>Retry-After</code> header. 066 * 067 * @param value The <code>Retry-After</code> header string. 068 * @return The parsed <code>Retry-After</code> header, or <jk>null</jk> if the string was null. 069 */ 070 public static RetryAfter forString(String value) { 071 if (value == null) 072 return null; 073 return new RetryAfter(value); 074 } 075 076 private RetryAfter(String value) { 077 super(value); 078 } 079 080 /** 081 * Returns this header value as a {@link java.util.Date} object. 082 * 083 * @return This header value as a {@link java.util.Date} object, or <jk>null</jk> if the value is not a date. 084 */ 085 public java.util.Date asDate() { 086 char c0 = charAt(value, 0); 087 if (c0 >= '0' && c0 <= '9') 088 return null; 089 return DateUtils.parseDate(toString()); 090 } 091 092 /** 093 * Returns this header value as an integer. 094 * 095 * @return This header value as a integer, or <code>-1</code> if the value is not an integer. 096 */ 097 public int asInt() { 098 char c0 = charAt(value, 0); 099 if (c0 >= '0' && c0 <= '9') { 100 try { 101 return Integer.parseInt(value); 102 } catch (NumberFormatException e) { 103 return -1; 104 } 105 } 106 return -1; 107 } 108}