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.tomcat.util.descriptor.tld;
18
19 import java.io.IOException;
20 import java.io.InputStream;
21 import java.net.URL;
22 import java.util.Objects;
23
24 import org.apache.tomcat.Jar;
25 import org.apache.tomcat.util.scan.JarFactory;
26 import org.apache.tomcat.util.scan.ReferenceCountedJar;
27
28 /**
29 * A TLD Resource Path as defined in JSP 7.3.2.
30 * <p>
31 * This encapsulates references to Tag Library Descriptors that can be located
32 * in different places:
33 * <ul>
34 * <li>As resources within an application</li>
35 * <li>As entries in JAR files included in the application</li>
36 * <li>As resources provided by the container</li>
37 * </ul>
38 * When configuring a mapping from a well-known URI to a TLD, a user is allowed
39 * to specify just the name of a JAR file that implicitly contains a TLD in
40 * <code>META-INF/taglib.tld</code>. Such a mapping must be explicitly converted
41 * to a URL and entryName when using this implementation.
42 */
43 public class TldResourcePath {
44 private final URL url;
45 private final String webappPath;
46 private final String entryName;
47
48 /**
49 * Constructor identifying a TLD resource directly.
50 *
51 * @param url the location of the TLD
52 * @param webappPath the web application path, if any, of the TLD
53 */
54 public TldResourcePath(URL url, String webappPath) {
55 this(url, webappPath, null);
56 }
57
58 /**
59 * Constructor identifying a TLD packaged within a JAR file.
60 *
61 * @param url the location of the JAR
62 * @param webappPath the web application path, if any, of the JAR
63 * @param entryName the name of the entry in the JAR
64 */
65 public TldResourcePath(URL url, String webappPath, String entryName) {
66 this.url = url;
67 this.webappPath = webappPath;
68 this.entryName = entryName;
69 }
70
71 /**
72 * Returns the URL of the TLD or of the JAR containing the TLD.
73 *
74 * @return the URL of the TLD
75 */
76 public URL getUrl() {
77 return url;
78 }
79
80 /**
81 * Returns the path within the web application, if any, that the resource
82 * returned by {@link #getUrl()} was obtained from.
83 *
84 * @return the web application path or @null if the the resource is not
85 * located within a web application
86 */
87 public String getWebappPath() {
88 return webappPath;
89 }
90
91 /**
92 * Returns the name of the JAR entry that contains the TLD.
93 * May be null to indicate the URL refers directly to the TLD itself.
94 *
95 * @return the name of the JAR entry that contains the TLD
96 */
97 public String getEntryName() {
98 return entryName;
99 }
100
101 /**
102 * Return the external form of the URL representing this TLD.
103 * This can be used as a canonical location for the TLD itself, for example,
104 * as the systemId to use when parsing its XML.
105 *
106 * @return the external form of the URL representing this TLD
107 */
108 public String toExternalForm() {
109 if (entryName == null) {
110 return url.toExternalForm();
111 } else {
112 return "jar:" + url.toExternalForm() + "!/" + entryName;
113 }
114 }
115
116 /**
117 * Opens a stream to access the TLD.
118 *
119 * @return a stream containing the TLD content
120 * @throws IOException if there was a problem opening the stream
121 */
122 public InputStream openStream() throws IOException {
123 if (entryName == null) {
124 return url.openStream();
125 } else {
126 URL entryUrl = JarFactory.getJarEntryURL(url, entryName);
127 return entryUrl.openStream();
128 }
129 }
130
131 public Jar openJar() throws IOException {
132 if (entryName == null) {
133 return null;
134 } else {
135 // Bug 62976
136 // Jar files containing tags are typically opened during initial
137 // compilation and then closed when compilation is complete. The
138 // reference counting wrapper is used because, when background
139 // compilation is enabled, the Jar will need to be accessed (to
140 // check for modifications) after it has been closed at the end
141 // of the compilation stage.
142 // Using a reference counted Jar enables the Jar to be re-opened,
143 // used and then closed again rather than triggering an ISE.
144 return new ReferenceCountedJar(url);
145 }
146 }
147
148 @Override
149 public boolean equals(Object o) {
150 if (this == o) {
151 return true;
152 }
153 if (o == null || getClass() != o.getClass()) {
154 return false;
155 }
156
157 TldResourcePath other = (TldResourcePath) o;
158
159 return url.equals(other.url) &&
160 Objects.equals(webappPath, other.webappPath) &&
161 Objects.equals(entryName, other.entryName);
162 }
163
164 @Override
165 public int hashCode() {
166 int result = url.hashCode();
167 result = result * 31 + Objects.hashCode(webappPath);
168 result = result * 31 + Objects.hashCode(entryName);
169 return result;
170 }
171 }
172