source: other-projects/trunk/gs3-release-maker/apache-ant-1.6.5/src/main/org/apache/tools/ant/taskdefs/optional/extension/JarLibResolveTask.java@ 14627

Last change on this file since 14627 was 14627, checked in by oranfry, 17 years ago

initial import of the gs3-release-maker
File size: 9.4 KB
Line 
1/*
2 * Copyright 2002-2004 The Apache Software Foundation
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *
16 */
17package org.apache.tools.ant.taskdefs.optional.extension;
18
19import java.io.File;
20import java.util.ArrayList;
21import java.util.jar.Manifest;
22import org.apache.tools.ant.BuildException;
23import org.apache.tools.ant.Project;
24import org.apache.tools.ant.Task;
25import org.apache.tools.ant.taskdefs.optional.extension.resolvers.AntResolver;
26import org.apache.tools.ant.taskdefs.optional.extension.resolvers.LocationResolver;
27import org.apache.tools.ant.taskdefs.optional.extension.resolvers.URLResolver;
28
29/**
30 * Tries to locate a JAR to satisfy an extension and place
31 * location of JAR into property.
32 *
33 * @ant.task name="jarlib-resolve"
34 */
35public class JarLibResolveTask extends Task {
36 /**
37 * The name of the property in which the location of
38 * library is stored.
39 */
40 private String propertyName;
41
42 /**
43 * The extension that is required.
44 */
45 private Extension requiredExtension;
46
47 /**
48 * The set of resolvers to use to attempt to locate library.
49 */
50 private final ArrayList resolvers = new ArrayList();
51
52 /**
53 * Flag to indicate that you should check that
54 * the librarys resolved actually contain
55 * extension and if they don't then raise
56 * an exception.
57 */
58 private boolean checkExtension = true;
59
60 /**
61 * Flag indicating whether or not you should
62 * throw a BuildException if you cannot resolve
63 * library.
64 */
65 private boolean failOnError = true;
66
67 /**
68 * The name of the property in which the location of
69 * library is stored.
70 *
71 * @param property The name of the property in which the location of
72 * library is stored.
73 */
74 public void setProperty(final String property) {
75 this.propertyName = property;
76 }
77
78 /**
79 * Check nested libraries for extensions
80 *
81 * @param checkExtension if true, libraries returned by nested
82 * resolvers should be checked to see if they supply extension.
83 */
84 public void setCheckExtension(final boolean checkExtension) {
85 this.checkExtension = checkExtension;
86 }
87
88 /**
89 * Set whether to fail if error.
90 *
91 * @param failOnError if true, failure to locate library should fail build.
92 */
93 public void setFailOnError(final boolean failOnError) {
94 this.failOnError = failOnError;
95 }
96
97 /**
98 * Adds location resolver to look for a library in a location
99 * relative to project directory.
100 *
101 * @param location the resolver location to search.
102 */
103 public void addConfiguredLocation(final LocationResolver location) {
104 resolvers.add(location);
105 }
106
107 /**
108 * Adds a URL resolver to download a library from a URL
109 * to a local file.
110 *
111 * @param url the URL resolver from which to download the library
112 */
113 public void addConfiguredUrl(final URLResolver url) {
114 resolvers.add(url);
115 }
116
117 /**
118 * Adds Ant resolver to run an Ant build file to generate a library.
119 *
120 * @param ant the AntResolver to generate the library.
121 */
122 public void addConfiguredAnt(final AntResolver ant) {
123 resolvers.add(ant);
124 }
125
126 /**
127 * Set the Extension looking for.
128 *
129 * @param extension Set the Extension looking for.
130 */
131 public void addConfiguredExtension(final ExtensionAdapter extension) {
132 if (null != requiredExtension) {
133 final String message = "Can not specify extension to "
134 + "resolve multiple times.";
135 throw new BuildException(message);
136 }
137 requiredExtension = extension.toExtension();
138 }
139
140 /**
141 * Execute the task.
142 *
143 * @throws BuildException if the task fails.
144 */
145 public void execute() throws BuildException {
146 validate();
147
148 getProject().log("Resolving extension: " + requiredExtension,
149 Project.MSG_VERBOSE);
150
151 String candidate =
152 getProject().getProperty(propertyName);
153
154 if (null != candidate) {
155 final String message = "Property Already set to: " + candidate;
156 if (failOnError) {
157 throw new BuildException(message);
158 } else {
159 getProject().log(message, Project.MSG_ERR);
160 return;
161 }
162 }
163
164 final int size = resolvers.size();
165 for (int i = 0; i < size; i++) {
166 final ExtensionResolver resolver =
167 (ExtensionResolver) resolvers.get(i);
168
169 getProject().log("Searching for extension using Resolver:" + resolver,
170 Project.MSG_VERBOSE);
171
172 try {
173 final File file =
174 resolver.resolve(requiredExtension, getProject());
175 try {
176 checkExtension(file);
177 return;
178 } catch (final BuildException be) {
179 final String message = "File " + file + " returned by "
180 + "resolver failed to satisfy extension due to: "
181 + be.getMessage();
182 getProject().log(message, Project.MSG_WARN);
183 }
184 } catch (final BuildException be) {
185 final String message = "Failed to resolve extension to file "
186 + "using resolver " + resolver + " due to: " + be;
187 getProject().log(message, Project.MSG_WARN);
188 }
189 }
190
191 missingExtension();
192 }
193
194 /**
195 * Utility method that will throw a {@link BuildException}
196 * if {@link #failOnError} is true else it just displays
197 * a warning.
198 */
199 private void missingExtension() {
200 final String message =
201 "Unable to resolve extension to a file";
202 if (failOnError) {
203 throw new BuildException(message);
204 } else {
205 getProject().log(message, Project.MSG_ERR);
206 }
207 }
208
209 /**
210 * Check if specified file satisfies extension.
211 * If it does then set the relevent property
212 * else throw a BuildException.
213 *
214 * @param file the candidate library
215 * @throws BuildException if library does not satisfy extension
216 */
217 private void checkExtension(final File file) {
218 if (!file.exists()) {
219 final String message =
220 "File " + file + " does not exist";
221 throw new BuildException(message);
222 }
223 if (!file.isFile()) {
224 final String message =
225 "File " + file + " is not a file";
226 throw new BuildException(message);
227 }
228
229 if (!checkExtension) {
230 final String message = "Setting property to " + file
231 + " without verifying library satisfies extension";
232 getProject().log(message, Project.MSG_VERBOSE);
233 setLibraryProperty(file);
234 } else {
235 getProject().log("Checking file " + file
236 + " to see if it satisfies extension", Project.MSG_VERBOSE);
237 final Manifest manifest =
238 ExtensionUtil.getManifest(file);
239 final Extension[] extensions =
240 Extension.getAvailable(manifest);
241 for (int i = 0; i < extensions.length; i++) {
242 final Extension extension = extensions[ i ];
243 if (extension.isCompatibleWith(requiredExtension)) {
244 setLibraryProperty(file);
245 return;
246 }
247 }
248
249 getProject().log("File " + file + " skipped as it "
250 + "does not satisfy extension", Project.MSG_VERBOSE);
251
252 final String message =
253 "File " + file + " does not satisfy extension";
254 throw new BuildException(message);
255 }
256 }
257
258 /**
259 * Utility method to set the appropriate property
260 * to indicate that specified file satisfies library
261 * requirements.
262 *
263 * @param file the library
264 */
265 private void setLibraryProperty(final File file) {
266 getProject().setNewProperty(propertyName,
267 file.getAbsolutePath());
268 }
269
270 /**
271 * Validate the tasks parameters.
272 *
273 * @throws BuildException if invalid parameters found
274 */
275 private void validate() throws BuildException {
276 if (null == propertyName) {
277 final String message = "Property attribute must be specified.";
278 throw new BuildException(message);
279 }
280
281 if (null == requiredExtension) {
282 final String message = "Extension element must be specified.";
283 throw new BuildException(message);
284 }
285 }
286}
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