001/*
002 * Copyright 2002-2017 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.messaging.support;
018
019import org.springframework.lang.Nullable;
020import org.springframework.messaging.MessageHeaders;
021import org.springframework.util.IdGenerator;
022
023/**
024 * A {@link org.springframework.messaging.support.MessageHeaderInitializer MessageHeaderInitializer}
025 * to customize the strategy for ID and TIMESTAMP message header generation.
026 *
027 * @author Rossen Stoyanchev
028 * @since 4.1
029 */
030public class IdTimestampMessageHeaderInitializer implements MessageHeaderInitializer {
031
032        private static final IdGenerator ID_VALUE_NONE_GENERATOR = () -> MessageHeaders.ID_VALUE_NONE;
033
034
035        @Nullable
036        private IdGenerator idGenerator;
037
038        private boolean enableTimestamp;
039
040
041        /**
042         * Configure the IdGenerator strategy to initialize {@code MessageHeaderAccessor}
043         * instances with.
044         * <p>By default this property is set to {@code null} in which case the default
045         * IdGenerator of {@link org.springframework.messaging.MessageHeaders} is used.
046         * <p>To have no ids generated at all, see {@link #setDisableIdGeneration()}.
047         */
048        public void setIdGenerator(@Nullable IdGenerator idGenerator) {
049                this.idGenerator = idGenerator;
050        }
051
052        /**
053         * Return the configured {@code IdGenerator}, if any.
054         */
055        @Nullable
056        public IdGenerator getIdGenerator() {
057                return this.idGenerator;
058        }
059
060        /**
061         * A shortcut for calling {@link #setIdGenerator} with an id generation strategy
062         * to disable id generation completely.
063         */
064        public void setDisableIdGeneration() {
065                this.idGenerator = ID_VALUE_NONE_GENERATOR;
066        }
067
068        /**
069         * Whether to enable the automatic addition of the
070         * {@link org.springframework.messaging.MessageHeaders#TIMESTAMP} header on
071         * {@code MessageHeaderAccessor} instances being initialized.
072         * <p>By default this property is set to false.
073         */
074        public void setEnableTimestamp(boolean enableTimestamp) {
075                this.enableTimestamp = enableTimestamp;
076        }
077
078        /**
079         * Return whether the timestamp header is enabled or not.
080         */
081        public boolean isEnableTimestamp() {
082                return this.enableTimestamp;
083        }
084
085
086        @Override
087        public void initHeaders(MessageHeaderAccessor headerAccessor) {
088                IdGenerator idGenerator = getIdGenerator();
089                if (idGenerator != null) {
090                        headerAccessor.setIdGenerator(idGenerator);
091                }
092                headerAccessor.setEnableTimestamp(isEnableTimestamp());
093        }
094
095}