001/*
002 * Copyright 2002-2012 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.beans.factory.support;
018
019import java.util.Properties;
020
021import org.springframework.beans.BeanMetadataElement;
022import org.springframework.beans.Mergeable;
023
024/**
025 * Tag class which represents a Spring-managed {@link Properties} instance
026 * that supports merging of parent/child definitions.
027 *
028 * @author Rob Harrop
029 * @author Juergen Hoeller
030 * @since 2.0
031 */
032@SuppressWarnings("serial")
033public class ManagedProperties extends Properties implements Mergeable, BeanMetadataElement {
034
035        private Object source;
036
037        private boolean mergeEnabled;
038
039
040        /**
041         * Set the configuration source {@code Object} for this metadata element.
042         * <p>The exact type of the object will depend on the configuration mechanism used.
043         */
044        public void setSource(Object source) {
045                this.source = source;
046        }
047
048        @Override
049        public Object getSource() {
050                return this.source;
051        }
052
053        /**
054         * Set whether merging should be enabled for this collection,
055         * in case of a 'parent' collection value being present.
056         */
057        public void setMergeEnabled(boolean mergeEnabled) {
058                this.mergeEnabled = mergeEnabled;
059        }
060
061        @Override
062        public boolean isMergeEnabled() {
063                return this.mergeEnabled;
064        }
065
066
067        @Override
068        public Object merge(Object parent) {
069                if (!this.mergeEnabled) {
070                        throw new IllegalStateException("Not allowed to merge when the 'mergeEnabled' property is set to 'false'");
071                }
072                if (parent == null) {
073                        return this;
074                }
075                if (!(parent instanceof Properties)) {
076                        throw new IllegalArgumentException("Cannot merge with object of type [" + parent.getClass() + "]");
077                }
078                Properties merged = new ManagedProperties();
079                merged.putAll((Properties) parent);
080                merged.putAll(this);
081                return merged;
082        }
083
084}