001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.jxpath.util;
019
020import org.apache.commons.jxpath.BasicNodeSet;
021import org.apache.commons.jxpath.ExtendedKeyManager;
022import org.apache.commons.jxpath.JXPathContext;
023import org.apache.commons.jxpath.KeyManager;
024import org.apache.commons.jxpath.NodeSet;
025import org.apache.commons.jxpath.Pointer;
026import org.apache.commons.jxpath.ri.InfoSetUtil;
027
028/**
029 * Utility class.
030 *
031 * @since JXPath 1.3
032 */
033public class KeyManagerUtils {
034
035    /**
036     * Adapt KeyManager to implement ExtendedKeyManager.
037     */
038    private static final class SingleNodeExtendedKeyManager implements ExtendedKeyManager {
039
040        private final KeyManager delegate;
041
042        /**
043         * Constructs a new SingleNodeExtendedKeyManager.
044         *
045         * @param delegate KeyManager to wrap
046         */
047        public SingleNodeExtendedKeyManager(final KeyManager delegate) {
048            this.delegate = delegate;
049        }
050
051        @Override
052        public NodeSet getNodeSetByKey(final JXPathContext context, final String key, final Object value) {
053            final Pointer pointer = delegate.getPointerByKey(context, key, InfoSetUtil.stringValue(value));
054            final BasicNodeSet result = new BasicNodeSet();
055            result.add(pointer);
056            return result;
057        }
058
059        @Override
060        public Pointer getPointerByKey(final JXPathContext context, final String keyName, final String keyValue) {
061            return delegate.getPointerByKey(context, keyName, keyValue);
062        }
063    }
064
065    /**
066     * Gets an ExtendedKeyManager from the specified KeyManager.
067     *
068     * @param keyManager to adapt, if necessary
069     * @return {@code keyManager} if it implements ExtendedKeyManager or a basic single-result ExtendedKeyManager that delegates to {@code keyManager}.
070     */
071    public static ExtendedKeyManager getExtendedKeyManager(final KeyManager keyManager) {
072        return keyManager instanceof ExtendedKeyManager ? (ExtendedKeyManager) keyManager : new SingleNodeExtendedKeyManager(keyManager);
073    }
074
075    /**
076     * Constructs a new instance.
077     *
078     * @deprecated Will be private in the next major version.
079     */
080    @Deprecated
081    public KeyManagerUtils() {
082        // empty
083    }
084}