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 java.util.Hashtable; 020 021 import org.apache.commons.discovery.ResourceNameDiscover; 022 import org.apache.commons.discovery.ResourceNameIterator; 023 import org.apache.commons.discovery.log.DiscoveryLogFactory; 024 import org.apache.commons.logging.Log; 025 026 027 /** 028 * Recover resource name from Managed Properties, 029 * using OLD property names. 030 * 031 * This class maintains a mapping between old names and 032 * (new) the class names they represent. The discovery 033 * mechanism uses the class names as property names. 034 * 035 * @see org.apache.commons.discovery.tools.ManagedProperties 036 * 037 * @author Richard A. Sitze 038 */ 039 public class DiscoverMappedNames 040 extends ResourceNameDiscoverImpl 041 implements ResourceNameDiscover 042 { 043 private static Log log = DiscoveryLogFactory.newLog(DiscoverMappedNames.class); 044 public static void setLog(Log _log) { 045 log = _log; 046 } 047 048 private Hashtable mapping = new Hashtable(); // String name ==> String[] newNames 049 050 /** Construct a new resource discoverer 051 */ 052 public DiscoverMappedNames() { 053 } 054 055 public void map(String fromName, String toName) { 056 mapping.put(fromName, toName); 057 } 058 059 public void map(String fromName, String [] toNames) { 060 mapping.put(fromName, toNames); 061 } 062 063 /** 064 * @return Enumeration of ResourceInfo 065 */ 066 public ResourceNameIterator findResourceNames(final String resourceName) { 067 if (log.isDebugEnabled()) { 068 log.debug("find: resourceName='" + resourceName + "', mapping to constants"); 069 } 070 071 final Object obj = mapping.get(resourceName); 072 073 final String[] names; 074 if (obj instanceof String) { 075 names = new String[] { (String)obj }; 076 } else if (obj instanceof String[]) { 077 names = (String[])obj; 078 } else { 079 names = null; 080 } 081 082 return new ResourceNameIterator() { 083 084 private int idx = 0; 085 086 public boolean hasNext() { 087 if (names != null) { 088 while (idx < names.length && names[idx] == null) { 089 idx++; 090 } 091 return idx < names.length; 092 } 093 return false; 094 } 095 096 public String nextResourceName() { 097 return hasNext() ? names[idx++] : null; 098 } 099 }; 100 } 101 }