/*
* 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 javax.servlet.http;
import java.util.Set;
/**
* Builds a push request based on the {@link HttpServletRequest} from which this
* builder was obtained. The push request will be constructed on the following
* basis:
* <ul>
* <li>The request method is set to <code>GET</code>.</li>
* <li>The path will not be set. This must be set explicitly via a call to
* {@link #path(String)}.</li>
* <li>Conditional, range, expectation, authorization and referer headers will
* be removed.</li>
* <li>Cookies added to the associated response will be added to the push
* request unless maxAge <= 0 in which case any request cookie with the
* same name will be removed.</li>
* <li>The referer header will be set to
* {@link HttpServletRequest#getRequestURL()} plus, if present, the query
* string from {@link HttpServletRequest#getQueryString()}.
* </ul>
*
* @since Servlet 4.0
*/
public interface PushBuilder {
/**
* Specify the HTTP method to use for the push request.
*
* @param method The method to use for the push request
*
* @return This builder instance
*
* @throws IllegalArgumentException if an HTTP method is specified that is
* known not to be <a
* href="https://tools.ietf.org/html/rfc7540#section-8.2">cacheable
* and safe</a>. POST, PUT, DELETE, CONNECT, OPTIONS and TRACE will
* trigger the exception.
*/
PushBuilder method(String method);
/**
* Specifies the query string to use in subsequent push requests generated
* by a call to {@link #push()}. This will be appended to any query string
* specified in the call to {@link #path(String)}.
*
* @param queryString The query string to use to generate push requests
*
* @return This builder instance
*/
PushBuilder queryString(String queryString);
/**
* Specifies the session ID to use in subsequent push requests generated
* by a call to {@link #push()}. The session ID will be presented the same
* way as it is on the original request (cookie or URL parameter). The
* default is determined in the following order:
* <ul>
* <li>the requested session ID for the originating request</li>
* <li>the session ID generated in the originated request</li>
* <li>{@code null}</li>
* </ul>
*
* @param sessionId The session ID to use to generate push requests
*
* @return This builder instance
*/
PushBuilder sessionId(String sessionId);
/**
* Sets a HTTP header on the request. Any existing headers of the same name
* are first remove.
*
* @param name The name of the header to set
* @param value The value of the header to set
*
* @return This builder instance
*/
PushBuilder setHeader(String name, String value);
/**
* Adds a HTTP header to the request.
*
* @param name The name of the header to add
* @param value The value of the header to add
*
* @return This builder instance
*/
PushBuilder addHeader(String name, String value);
/**
* Removes an HTTP header from the request.
*
* @param name The name of the header to remove
*
* @return This builder instance
*/
PushBuilder removeHeader(String name);
/**
* Sets the URI path to be used for the push request. This must be called
* before every call to {@link #push()}. If the path includes a query
* string, the query string will be appended to the existing query string
* (if any) and no de-duplication will occur.
*
* @param path Paths beginning with '/' are treated as absolute paths. All
* other paths are treated as relative to the context path of
* the request used to create this builder instance. The path
* may include a query string.
*
* @return This builder instance
*/
PushBuilder path(String path);
/**
* Generates the push request and sends it to the client unless pushes are
* not available for some reason. After calling this method the following
* fields are set to {@code null}:
* <ul>
* <li>{@code path}</li>
* <li>{@code etag}</li>
* <li>{@code lastModified}</li>
* </ul>
*
* @throws IllegalStateException If this method is called when {@code path}
* is {@code null}
* @throws IllegalArgumentException If the request to push requires a body
*/
void push();
/**
* Obtain the name of the HTTP method that will be used for push requests
* generated by future calls to {@code push()}.
*
* @return The HTTP method to be used for future push requests
*/
String getMethod();
/**
* Obtain the query string that will be used for push requests generated by
* future calls to {@code push()}.
*
* @return The query string that will be appended to push requests.
*/
String getQueryString();
/**
* Obtain the session ID that will be used for push requests generated by
* future calls to {@code push()}.
*
* @return The session that will be used for push requests.
*/
String getSessionId();
/**
* @return The current set of names of HTTP headers to be used the next time
* {@code push()} is called.
*/
Set<String> getHeaderNames();
/**
* Obtain a value for the given HTTP header.
* TODO Servlet 4.0
* Clarify the behaviour of this method
*
* @param name The name of the header whose value is to be returned
*
* @return The value of the given header. If multiple values are defined
* then any may be returned
*/
String getHeader(String name);
/**
* Obtain the path that will be used for the push request that will be
* generated by the next call to {@code push()}.
*
* @return The path value that will be associated with the next push request
*/
String getPath();
}