| // *************************************************************************************************************************** |
| // * 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.juneau.http; |
| |
| import static org.apache.juneau.http.Constants.*; |
| |
| import org.apache.juneau.http.annotation.*; |
| import org.apache.juneau.internal.*; |
| |
| /** |
| * Represents a parsed <l>TE</l> HTTP request header. |
| * |
| * <p> |
| * The transfer encodings the user agent is willing to accept: the same values as for the response header field |
| * Transfer-Encoding can be used, plus the "trailers" value (related to the "chunked" transfer method) to notify the |
| * server it expects to receive additional fields in the trailer after the last, zero-sized, chunk. |
| * |
| * <h5 class='figure'>Example</h5> |
| * <p class='bcode w800'> |
| * TE: trailers, deflate |
| * </p> |
| * |
| * <h5 class='topic'>RFC2616 Specification</h5> |
| * |
| * The TE request-header field indicates what extension transfer-codings it is willing to accept in the response and |
| * whether or not it is willing to accept trailer fields in a chunked transfer-coding. |
| * Its value may consist of the keyword "trailers" and/or a comma-separated list of extension transfer-coding names |
| * with optional accept parameters (as described in section 3.6). |
| * |
| * <p class='bcode w800'> |
| * TE = "TE" ":" #( t-codings ) |
| * t-codings = "trailers" | ( transfer-extension [ accept-params ] ) |
| * </p> |
| * |
| * <p> |
| * The presence of the keyword "trailers" indicates that the client is willing to accept trailer fields in a chunked |
| * transfer-coding, as defined in section 3.6.1. |
| * This keyword is reserved for use with transfer-coding values even though it does not itself represent a |
| * transfer-coding. |
| * |
| * <p> |
| * Examples of its use are: |
| * <p class='bcode w800'> |
| * TE: deflate |
| * TE: |
| * TE: trailers, deflate;q=0.5 |
| * </p> |
| * |
| * <p> |
| * The TE header field only applies to the immediate connection. |
| * Therefore, the keyword MUST be supplied within a Connection header field (section 14.10) whenever TE is present in |
| * an HTTP/1.1 message. |
| * |
| * <p> |
| * A server tests whether a transfer-coding is acceptable, according to a TE field, using these rules: |
| * <ol> |
| * <li>The "chunked" transfer-coding is always acceptable. |
| * If the keyword "trailers" is listed, the client indicates that it is willing to accept trailer fields in the |
| * chunked response on behalf of itself and any downstream clients. |
| * The implication is that, if given, the client is stating that either all downstream clients are willing to accept |
| * trailer fields in the forwarded response, or that it will attempt to buffer the response on behalf of downstream |
| * recipients. |
| * Note: HTTP/1.1 does not define any means to limit the size of a chunked response such that a client can be assured |
| * of buffering the entire response. |
| * <li>If the transfer-coding being tested is one of the transfer-codings listed in the TE field, then it is acceptable |
| * unless it is accompanied by a qvalue of 0. (As defined in section 3.9, a qvalue of 0 means "not acceptable.") |
| * <li>If multiple transfer-codings are acceptable, then the acceptable transfer-coding with the highest non-zero |
| * qvalue is preferred. |
| * The "chunked" transfer-coding always has a qvalue of 1. |
| * </ol> |
| * |
| * <p> |
| * If the TE field-value is empty or if no TE field is present, the only transfer-coding is "chunked". |
| * A message with no transfer-coding is always acceptable. |
| * |
| * <ul class='seealso'> |
| * <li class='extlink'>{@doc RFC2616} |
| * </ul> |
| */ |
| @Header("TE") |
| public final class TE extends HeaderRangeArray { |
| |
| private static final Cache<String,TE> cache = new Cache<>(NOCACHE, CACHE_MAX_SIZE); |
| |
| /** |
| * Returns a parsed <c>TE</c> header. |
| * |
| * @param value The <c>TE</c> header string. |
| * @return The parsed <c>TE</c> header, or <jk>null</jk> if the string was null. |
| */ |
| public static TE forString(String value) { |
| if (value == null) |
| return null; |
| TE te = cache.get(value); |
| if (te == null) |
| te = cache.put(value, new TE(value)); |
| return te; |
| } |
| |
| private TE(String value) { |
| super(value); |
| } |
| } |