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.classes;
  58. import java.net.URL;
  59. import java.util.Vector;
  60. import org.apache.commons.discovery.ResourceClass;
  61. import org.apache.commons.discovery.ResourceClassDiscover;
  62. import org.apache.commons.discovery.ResourceClassIterator;
  63. import org.apache.commons.discovery.log.DiscoveryLogFactory;
  64. import org.apache.commons.discovery.resource.ClassLoaders;
  65. import org.apache.commons.logging.Log;
  66. /**
  67. * The findResources() method will check every loader.
  68. *
  69. * @author Richard A. Sitze
  70. * @author Craig R. McClanahan
  71. * @author Costin Manolache
  72. * @author James Strachan
  73. */
  74. public class DiscoverClasses
  75. extends ResourceClassDiscoverImpl
  76. implements ResourceClassDiscover
  77. {
  78. private static Log log = DiscoveryLogFactory.newLog(DiscoverClasses.class);
  79. public static void setLog(Log _log) {
  80. log = _log;
  81. }
  82. /** Construct a new resource discoverer
  83. */
  84. public DiscoverClasses() {
  85. super();
  86. }
  87. /** Construct a new resource discoverer
  88. */
  89. public DiscoverClasses(ClassLoaders classLoaders) {
  90. super(classLoaders);
  91. }
  92. public ResourceClassIterator findResourceClasses(final String className) {
  93. final String resourceName = className.replace('.','/') + ".class";
  94. if (log.isDebugEnabled())
  95. log.debug("find: className='" + className + "'");
  96. return new ResourceClassIterator() {
  97. private Vector history = new Vector();
  98. private int idx = 0;
  99. private ResourceClass resource = null;
  100. public boolean hasNext() {
  101. if (resource == null) {
  102. resource = getNextClass();
  103. }
  104. return resource != null;
  105. }
  106. public ResourceClass nextResourceClass() {
  107. ResourceClass element = resource;
  108. resource = null;
  109. return element;
  110. }
  111. private ResourceClass getNextClass() {
  112. while (idx < getClassLoaders().size()) {
  113. ClassLoader loader = getClassLoaders().get(idx++);
  114. URL url = loader.getResource(resourceName);
  115. if (url != null) {
  116. if (!history.contains(url)) {
  117. history.addElement(url);
  118. if (log.isDebugEnabled())
  119. log.debug("getNextClass: next URL='" + url + "'");
  120. return new ResourceClass(className, url, loader);
  121. }
  122. if (log.isDebugEnabled())
  123. log.debug("getNextClass: duplicate URL='" + url + "'");
  124. } else {
  125. if (log.isDebugEnabled())
  126. log.debug("getNextClass: loader " + loader + ": '" + resourceName + "' not found");
  127. }
  128. }
  129. return null;
  130. }
  131. };
  132. }
  133. }