1. /*
  2. * ====================================================================
  3. *
  4. * The Apache Software License, Version 1.1
  5. *
  6. * Copyright (c) 1999-2002 The Apache Software Foundation. All rights
  7. * reserved.
  8. *
  9. * Redistribution and use in source and binary forms, with or without
  10. * modification, are permitted provided that the following conditions
  11. * are met:
  12. *
  13. * 1. Redistributions of source code must retain the above copyright
  14. * notice, this list of conditions and the following disclaimer.
  15. *
  16. * 2. Redistributions in binary form must reproduce the above copyright
  17. * notice, this list of conditions and the following disclaimer in
  18. * the documentation and/or other materials provided with the
  19. * distribution.
  20. *
  21. * 3. The end-user documentation included with the redistribution, if
  22. * any, must include the following acknowlegement:
  23. * "This product includes software developed by the
  24. * Apache Software Foundation (http://www.apache.org/)."
  25. * Alternately, this acknowlegement may appear in the software itself,
  26. * if and wherever such third-party acknowlegements normally appear.
  27. *
  28. * 4. The names "The Jakarta Project", "Commons", and "Apache Software
  29. * Foundation" must not be used to endorse or promote products derived
  30. * from this software without prior written permission. For written
  31. * permission, please contact apache@apache.org.
  32. *
  33. * 5. Products derived from this software may not be called "Apache"
  34. * nor may "Apache" appear in their names without prior written
  35. * permission of the Apache Group.
  36. *
  37. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
  38. * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  39. * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  40. * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
  41. * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  42. * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  43. * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  44. * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  45. * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  46. * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  47. * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  48. * SUCH DAMAGE.
  49. * ====================================================================
  50. *
  51. * This software consists of voluntary contributions made by many
  52. * individuals on behalf of the Apache Software Foundation. For more
  53. * information on the Apache Software Foundation, please see
  54. * <http://www.apache.org/>.
  55. *
  56. */
  57. package org.apache.commons.discovery.resource.names;
  58. import java.util.Vector;
  59. import org.apache.commons.discovery.ResourceNameDiscover;
  60. import org.apache.commons.discovery.ResourceNameIterator;
  61. import org.apache.commons.discovery.log.DiscoveryLogFactory;
  62. import org.apache.commons.logging.Log;
  63. /**
  64. * Holder for multiple ResourceNameDiscover instances.
  65. * The result is the union of the results from each
  66. * (not a chained sequence, where results feed the next in line.
  67. *
  68. * @author Richard A. Sitze
  69. */
  70. public class NameDiscoverers
  71. extends ResourceNameDiscoverImpl
  72. implements ResourceNameDiscover
  73. {
  74. private static Log log = DiscoveryLogFactory.newLog(NameDiscoverers.class);
  75. public static void setLog(Log _log) {
  76. log = _log;
  77. }
  78. private Vector discoverers = new Vector();
  79. /**
  80. * Construct a new resource name discoverer
  81. */
  82. public NameDiscoverers() {
  83. }
  84. /**
  85. * Specify an additional class loader to be used in searching.
  86. * The order of loaders determines the order of the result.
  87. * It is recommended to add the most specific loaders first.
  88. */
  89. public void addResourceNameDiscover(ResourceNameDiscover discover) {
  90. if (discover != null) {
  91. discoverers.addElement(discover);
  92. }
  93. }
  94. protected ResourceNameDiscover getResourceNameDiscover(int idx) {
  95. return (ResourceNameDiscover)discoverers.get(idx);
  96. }
  97. protected int size() {
  98. return discoverers.size();
  99. }
  100. /**
  101. * Set of results of all discoverers.
  102. *
  103. * @return ResourceIterator
  104. */
  105. public ResourceNameIterator findResourceNames(final String resourceName) {
  106. if (log.isDebugEnabled())
  107. log.debug("find: resourceName='" + resourceName + "'");
  108. return new ResourceNameIterator() {
  109. private int idx = 0;
  110. private ResourceNameIterator iterator = null;
  111. public boolean hasNext() {
  112. if (iterator == null || !iterator.hasNext()) {
  113. iterator = getNextIterator();
  114. if (iterator == null) {
  115. return false;
  116. }
  117. }
  118. return iterator.hasNext();
  119. }
  120. public String nextResourceName() {
  121. return iterator.nextResourceName();
  122. }
  123. private ResourceNameIterator getNextIterator() {
  124. while (idx < size()) {
  125. ResourceNameIterator iter =
  126. getResourceNameDiscover(idx++).findResourceNames(resourceName);
  127. if (iter.hasNext()) {
  128. return iter;
  129. }
  130. }
  131. return null;
  132. }
  133. };
  134. }
  135. }