1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.discovery.resource.names;
18
19 import org.apache.commons.discovery.ResourceNameDiscover;
20 import org.apache.commons.discovery.ResourceNameIterator;
21 import org.apache.commons.logging.Log;
22 import org.apache.commons.logging.LogFactory;
23
24 /**
25 * Recover resource name from System Properties.
26 */
27 public class DiscoverNamesInSystemProperties extends ResourceNameDiscoverImpl implements ResourceNameDiscover {
28
29 private static Log log = LogFactory.getLog(DiscoverNamesInSystemProperties.class);
30
31 /**
32 * Sets the {@code Log} for this class.
33 *
34 * @param _log This class {@code Log}
35 * @deprecated This method is not thread-safe
36 */
37 @Deprecated
38 public static void setLog(Log _log) {
39 log = _log;
40 }
41
42 /**
43 * Construct a new resource discoverer
44 */
45 public DiscoverNamesInSystemProperties() {
46 }
47
48 /**
49 * {@inheritDoc}
50 */
51 @Override
52 public ResourceNameIterator findResourceNames(final String resourceName) {
53 if (log.isDebugEnabled()) {
54 log.debug("find: resourceName='" + resourceName + "'");
55 }
56
57 return new ResourceNameIterator() {
58
59 private String resource = System.getProperty(resourceName);
60
61 public boolean hasNext() {
62 return resource != null;
63 }
64
65 public String nextResourceName() {
66 String element = resource;
67 resource = null;
68 return element;
69 }
70 };
71 }
72
73 }