/* * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.net.http; import java.util.ArrayList; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.Optional; import java.util.OptionalLong; import java.util.TreeMap; import java.util.TreeSet; import java.util.function.BiPredicate; import static java.lang.String.CASE_INSENSITIVE_ORDER; import static java.util.Collections.unmodifiableMap; import static java.util.Objects.requireNonNull; /** * A read-only view of a set of HTTP headers. * *
An {@code HttpHeaders} is not typically created directly, but rather * returned from an {@link HttpRequest#headers() HttpRequest} or an * {@link HttpResponse#headers() HttpResponse}. Specific HTTP headers can be * set for a {@linkplain HttpRequest request} through one of the request * builder's {@link HttpRequest.Builder#header(String, String) headers} methods. * *
The methods of this class ( that accept a String header name ), and the * {@code Map} returned by the {@link #map() map} method, operate without regard * to case when retrieving the header value(s). * *
An HTTP header name may appear more than once in the HTTP protocol. As * such, headers are represented as a name and a list of values. Each occurrence * of a header value is added verbatim, to the appropriate header name list, * without interpreting its value. In particular, {@code HttpHeaders} does not * perform any splitting or joining of comma separated header value strings. The * order of elements in a header value list is preserved when {@link * HttpRequest.Builder#header(String, String) building} a request. For * responses, the order of elements in a header value list is the order in which * they were received. The {@code Map} returned by the {@code map} method, * however, does not provide any guarantee with regard to the ordering of its * entries. * *
{@code HttpHeaders} instances are immutable.
*
* @since 11
*/
public final class HttpHeaders {
/**
* Returns an {@link Optional} containing the first header string value of
* the given named (and possibly multi-valued) header. If the header is not
* present, then the returned {@code Optional} is empty.
*
* @param name the header name
* @return an {@code Optional If the given object is not an {@code HttpHeaders} then this
* method returns {@code false}. Two HTTP headers are equal if each
* of their corresponding {@linkplain #map() maps} are equal.
*
* This method satisfies the general contract of the {@link
* Object#equals(Object) Object.equals} method.
*
* @param obj the object to which this object is to be compared
* @return {@code true} if, and only if, the given object is an {@code
* HttpHeaders} that is equal to this HTTP headers
*/
public final boolean equals(Object obj) {
if (!(obj instanceof HttpHeaders))
return false;
HttpHeaders that = (HttpHeaders)obj;
return this.map().equals(that.map());
}
/**
* Computes a hash code for this HTTP headers instance.
*
* The hash code is based upon the components of the HTTP headers
* {@link #map() map}, and satisfies the general contract of the
* {@link Object#hashCode Object.hashCode} method.
*
* @return the hash-code value for this HTTP headers
*/
public final int hashCode() {
return map().hashCode();
}
/**
* Returns this HTTP headers as a string.
*
* @return a string describing the HTTP headers
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(super.toString()).append(" { ");
sb.append(map());
sb.append(" }");
return sb.toString();
}
/**
* Returns an HTTP headers from the given map. The given map's key
* represents the header name, and its value the list of string header
* values for that header name.
*
* An HTTP header name may appear more than once in the HTTP protocol.
* Such, multi-valued, headers must be represented by a single entry
* in the given map, whose entry value is a list that represents the
* multiple header string values. Leading and trailing whitespaces are
* removed from all string values retrieved from the given map and its lists
* before processing. Only headers that, after filtering, contain at least
* one, possibly empty string, value will be added to the HTTP headers.
*
* @apiNote The primary purpose of this method is for testing frameworks.
* Per-request headers can be set through one of the {@code HttpRequest}
* {@link HttpRequest.Builder#header(String, String) headers} methods.
*
* @param headerMap the map containing the header names and values
* @param filter a filter that can be used to inspect each
* header-name-and-value pair in the given map to determine if
* it should, or should not, be added to the to the HTTP
* headers
* @return an HTTP headers instance containing the given headers
* @throws NullPointerException if any of: {@code headerMap}, a key or value
* in the given map, or an entry in the map's value list, or
* {@code filter}, is {@code null}
* @throws IllegalArgumentException if the given {@code headerMap} contains
* any two keys that are equal ( without regard to case ); or if the
* given map contains any key whose length, after trimming
* whitespaces, is {@code 0}
*/
public static HttpHeaders of(Map