    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    package org.apache.commons.jxpath.util;
    018
    019    import org.apache.commons.jxpath.BasicNodeSet;
    020    import org.apache.commons.jxpath.ExtendedKeyManager;
    021    import org.apache.commons.jxpath.JXPathContext;
    022    import org.apache.commons.jxpath.KeyManager;
    023    import org.apache.commons.jxpath.NodeSet;
    024    import org.apache.commons.jxpath.Pointer;
    025    import org.apache.commons.jxpath.ri.InfoSetUtil;
    026
    027    /**
    028     * Utility class.
    029     *
    030     * @author Matt Benson
    031     * @since JXPath 1.3
    032     * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
    033     */
    034    public class KeyManagerUtils {
    035        /**
    036         * Adapt KeyManager to implement ExtendedKeyManager.
    037         */
    038        private static class SingleNodeExtendedKeyManager implements
    039                ExtendedKeyManager {
    040            private KeyManager delegate;
    041
    042            /**
    043             * Create a new SingleNodeExtendedKeyManager.
    044             * @param delegate KeyManager to wrap
    045             */
    046            public SingleNodeExtendedKeyManager(KeyManager delegate) {
    047                this.delegate = delegate;
    048            }
    049
    050            public NodeSet getNodeSetByKey(JXPathContext context, String key,
    051                    Object value) {
    052                Pointer pointer = delegate.getPointerByKey(context, key, InfoSetUtil.stringValue(value));
    053                BasicNodeSet result = new BasicNodeSet();
    054                result.add(pointer);
    055                return result;
    056            }
    057
    058            public Pointer getPointerByKey(JXPathContext context, String keyName,
    059                    String keyValue) {
    060                return delegate.getPointerByKey(context, keyName, keyValue);
    061            }
    062        }
    063
    064        /**
    065         * Get an ExtendedKeyManager from the specified KeyManager.
    066         * @param keyManager to adapt, if necessary
    067         * @return <code>keyManager</code> if it implements ExtendedKeyManager
    068         *         or a basic single-result ExtendedKeyManager that delegates to
    069         *         <code>keyManager</code>.
    070         */
    071        public static ExtendedKeyManager getExtendedKeyManager(KeyManager keyManager) {
    072            return keyManager instanceof ExtendedKeyManager ? (ExtendedKeyManager) keyManager
    073                    : new SingleNodeExtendedKeyManager(keyManager);
    074        }
    075    }