01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one or more
03: * contributor license agreements. See the NOTICE file distributed with
04: * this work for additional information regarding copyright ownership.
05: * The ASF licenses this file to You under the Apache License, Version 2.0
06: * (the "License"); you may not use this file except in compliance with
07: * the License. You may obtain a copy of the License at
08: *
09: * 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:
22: /**
23: * Helper class for methods implementing the ResourceNameDiscover interface.
24: *
25: * @author Richard A. Sitze
26: */
27: public abstract class ResourceNameDiscoverImpl implements
28: ResourceNameDiscover {
29: /**
30: * Locate names of resources that are bound to <code>resourceName</code>.
31: *
32: * @return ResourceNameIterator
33: */
34: public abstract ResourceNameIterator findResourceNames(
35: String resourceName);
36:
37: /**
38: * Locate names of resources that are bound to <code>resourceName</code>.
39: *
40: * @return ResourceNameIterator
41: */
42: public ResourceNameIterator findResourceNames(
43: final ResourceNameIterator inputNames) {
44: return new ResourceNameIterator() {
45: private ResourceNameIterator resourceNames = null;
46: private String resourceName = null;
47:
48: public boolean hasNext() {
49: if (resourceName == null) {
50: resourceName = getNextResourceName();
51: }
52: return resourceName != null;
53: }
54:
55: public String nextResourceName() {
56: String name = resourceName;
57: resourceName = null;
58: return name;
59: }
60:
61: private String getNextResourceName() {
62: while (inputNames.hasNext()
63: && (resourceNames == null || !resourceNames
64: .hasNext())) {
65: resourceNames = findResourceNames(inputNames
66: .nextResourceName());
67: }
68:
69: return (resourceNames != null && resourceNames
70: .hasNext()) ? resourceNames.nextResourceName()
71: : null;
72: }
73: };
74: }
75: }
|