org.osgi.service.http.whiteboard.Preprocessor Maven / Gradle / Ivy
Show all versions of aem-sdk-api Show documentation
/*******************************************************************************
* Copyright (c) Contributors to the Eclipse Foundation
*
* Licensed 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.
*
* SPDX-License-Identifier: Apache-2.0
*******************************************************************************/
package org.osgi.service.http.whiteboard;
import javax.servlet.Filter;
import org.osgi.annotation.versioning.ConsumerType;
/**
* Services registered as a {@code Preprocessor} using a whiteboard pattern are
* executed for every request before the dispatching is performed.
*
* If there are several services of this type, they are run in order of their
* service ranking, the one with the highest ranking is used first. In the case
* of a service ranking tie, the service with the lowest service id is processed
* first.
*
* The preprocessor is handled in the same way as filters. When a preprocessor
* is put into service {@link Filter#init(javax.servlet.FilterConfig)} is
* called, when it is not used anymore {@link Filter#destroy()} is called. As
* these preprocessors are run before dispatching and therefore the targeted
* servlet context is not known yet,
* {@link javax.servlet.FilterConfig#getServletContext()} returns the servlet
* context of the backing implementation. The same context is returned by the
* request object. The context path is the context path of this underlying
* servlet context. The passed in chain can be used to invoke the next
* preprocessor in the chain, or if the end of that chain is reached to start
* dispatching of the request. A preprocessor might decide to terminate the
* processing and directly generate a response.
*
* Service properties with the prefix
* {@code HttpWhiteboardConstants#HTTP_WHITEBOARD_PREPROCESSOR_INIT_PARAM_PREFIX}
* are passed as init parameters to this service.
*
* @ThreadSafe
* @author $Id: 5f0ef75b6a0690898e1602299f0163964ffa1c34 $
* @since 1.1
*/
@ConsumerType
public interface Preprocessor extends Filter {
// this interface is a marker interface
}