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 }