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.discovery.resource.names;
018    
019    import org.apache.commons.discovery.ResourceNameDiscover;
020    import org.apache.commons.discovery.ResourceNameIterator;
021    import org.apache.commons.discovery.log.DiscoveryLogFactory;
022    import org.apache.commons.discovery.tools.ManagedProperties;
023    import org.apache.commons.logging.Log;
024    
025    
026    /**
027     * Recover resource name from Managed Properties.
028     * @see org.apache.commons.discovery.tools.ManagedProperties
029     * 
030     * @author Richard A. Sitze
031     */
032    public class DiscoverNamesInManagedProperties
033        extends ResourceNameDiscoverImpl
034        implements ResourceNameDiscover
035    {
036        private static Log log = DiscoveryLogFactory.newLog(DiscoverNamesInManagedProperties.class);
037        public static void setLog(Log _log) {
038            log = _log;
039        }
040    
041        
042        private final String _prefix;
043        private final String _suffix;
044        
045        /** Construct a new resource discoverer
046         */
047        public DiscoverNamesInManagedProperties() {
048            _prefix = null;
049            _suffix = null;
050        }
051        
052        /** Construct a new resource discoverer
053         */
054        public DiscoverNamesInManagedProperties(String prefix, String suffix) {
055            _prefix = prefix;
056            _suffix = suffix;
057        }
058    
059        /**
060         * @return Enumeration of ResourceInfo
061         */
062        public ResourceNameIterator findResourceNames(final String resourceName) {
063            String name;
064            if (_prefix != null && _prefix.length() > 0) {
065                name = _prefix + resourceName;
066            } else {
067                name = resourceName;
068            }
069    
070            if (_suffix != null && _suffix.length() > 0) {
071                name = name + _suffix;
072            }
073    
074            if (log.isDebugEnabled()) {
075                if (_prefix != null  &&  _suffix != null) {
076                    log.debug("find: resourceName='" + resourceName + "' as '" + name + "'");
077                } else {
078                    log.debug("find: resourceName = '" + name + "'");
079                }
080            }
081    
082            final String newResourcName = name;
083            return new ResourceNameIterator() {
084                private String resource = ManagedProperties.getProperty(newResourcName);
085                public boolean hasNext() {
086                    return resource != null;
087                }
088                
089                public String nextResourceName() {
090                    String element = resource;
091                    resource = null;
092                    return element;
093                }
094            };
095        }
096    }