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See the License for the * 011// * specific language governing permissions and limitations under the License. * 012// *************************************************************************************************************************** 013package org.apache.juneau.http.header; 014 015import static org.apache.juneau.http.Constants.*; 016 017import java.util.function.*; 018 019import org.apache.juneau.http.*; 020import org.apache.juneau.http.annotation.*; 021import org.apache.juneau.internal.*; 022 023 024/** 025 * Represents a parsed <l>Accept-Charset</l> HTTP request header. 026 * 027 * <p> 028 * Character sets that are acceptable. 029 * 030 * <h5 class='figure'>Example</h5> 031 * <p class='bcode w800'> 032 * Accept-Charset: utf-8 033 * </p> 034 * 035 * <h5 class='topic'>RFC2616 Specification</h5> 036 * 037 * The Accept-Charset request-header field can be used to indicate what character sets are acceptable for the response. 038 * 039 * <p> 040 * This field allows clients capable of understanding more comprehensive or special- purpose character sets to signal 041 * that capability to a server which is capable of representing documents in those character sets. 042 * <p class='bcode w800'> 043 * Accept-Charset = "Accept-Charset" ":" 044 * 1#( ( charset | "*" )[ ";" "q" "=" qvalue ] ) 045 * </p> 046 * 047 * <p> 048 * Character set values are described in section 3.4. Each charset MAY be given an associated quality value which 049 * represents the user's preference for that charset. 050 * The default value is q=1. 051 * An example is... 052 * <p class='bcode w800'> 053 * Accept-Charset: iso-8859-5, unicode-1-1;q=0.8 054 * </p> 055 * 056 * <p> 057 * The special value "*", if present in the Accept-Charset field, matches every character set (including ISO-8859-1) 058 * which is not mentioned elsewhere in the Accept-Charset field. 059 * 060 * <p> 061 * If no "*" is present in an Accept-Charset field, then all character sets not explicitly mentioned get a quality 062 * value of 0, except for ISO-8859-1, which gets a quality value of 1 if not explicitly mentioned. 063 * 064 * <p> 065 * If no Accept-Charset header is present, the default is that any character set is acceptable. 066 * 067 * <p> 068 * If an Accept-Charset header is present, and if the server cannot send a response which is acceptable according to 069 * the Accept-Charset header, then the server SHOULD send an error response with the 406 (not acceptable) status code, 070 * though the sending of an unacceptable response is also allowed. 071 * 072 * <ul class='seealso'> 073 * <li class='extlink'>{@doc ExtRFC2616} 074 * </ul> 075 */ 076@Header("Accept-Charset") 077public class AcceptCharset extends BasicStringRangeArrayHeader { 078 079 private static final long serialVersionUID = 1L; 080 081 private static final Cache<String,AcceptCharset> CACHE = new Cache<>(NOCACHE, CACHE_MAX_SIZE); 082 083 /** 084 * Returns a parsed and cached header. 085 * 086 * @param value 087 * The header value. 088 * @return A cached {@link AcceptCharset} object. 089 */ 090 public static AcceptCharset of(String value) { 091 if (value == null) 092 return null; 093 AcceptCharset x = CACHE.get(value); 094 if (x == null) 095 x = CACHE.put(value, new AcceptCharset(value)); 096 return x; 097 } 098 099 /** 100 * Convenience creator. 101 * 102 * @param value 103 * The header value. 104 * <br>Can be any of the following: 105 * <ul> 106 * <li>{@link String} - Converted using {@link StringRanges#of(String)}. 107 * <li><c>StringRange[]</c> - Left as-is. 108 * <li>Anything else - Converted to <c>String</c> then parsed. 109 * </ul> 110 * @return A new {@link AcceptCharset} object. 111 */ 112 public static AcceptCharset of(Object value) { 113 if (value == null) 114 return null; 115 return new AcceptCharset(value); 116 } 117 118 /** 119 * Convenience creator using supplier. 120 * 121 * <p> 122 * Header value is re-evaluated on each call to {@link #getValue()}. 123 * 124 * @param value 125 * The header value supplier. 126 * <br>Can be any of the following: 127 * <ul> 128 * <li>{@link String} - Converted using {@link StringRanges#of(String)}. 129 * <li><c>StringRange[]</c> - Left as-is. 130 * <li>Anything else - Converted to <c>String</c> then parsed. 131 * </ul> 132 * @return A new {@link AcceptCharset} object. 133 */ 134 public static AcceptCharset of(Supplier<?> value) { 135 if (value == null) 136 return null; 137 return new AcceptCharset(value); 138 } 139 140 /** 141 * Constructor 142 * 143 * @param value 144 * The header value. 145 * <br>Can be any of the following: 146 * <ul> 147 * <li>{@link String} - Converted using {@link StringRanges#of(String)}. 148 * <li><c>StringRange[]</c> - Left as-is. 149 * <li>Anything else - Converted to <c>String</c> then parsed. 150 * <li>A {@link Supplier} of anything on this list. 151 * </ul> 152 */ 153 public AcceptCharset(Object value) { 154 super("Accept-Charset", value); 155 } 156 157 /** 158 * Constructor 159 * 160 * @param value 161 * The header value. 162 */ 163 public AcceptCharset(String value) { 164 this((Object)value); 165 } 166}