Resource


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   */
18  package org.apache.tools.ant.types;
19  
20  import java.io.InputStream  ;
21  import java.io.IOException  ;
22  import java.io.OutputStream  ;
23  import java.math.BigInteger  ;
24  import java.util.Iterator  ;
25  import java.util.NoSuchElementException  ;
26  
27  /**
28   * Describes a "File-like" resource (File, ZipEntry, etc.).
29   *
30   * This class is meant to be used by classes needing to record path
31   * and date/time information about a file, a zip entry or some similar
32   * resource (URL, archive in a version control repository, ...).
33   *
34   * @since Ant 1.5.2
35   * @see org.apache.tools.ant.types.resources.Touchable
36   */
37  public class Resource extends DataType
38      implements Cloneable  , Comparable  , ResourceCollection {
39  
40      /** Constant unknown size */
41      public static final long UNKNOWN_SIZE = -1;
42  
43      /** Constant unknown datetime for getLastModified */
44      public static final long UNKNOWN_DATETIME = 0L;
45  
46      /** Magic number */
47      protected static final int MAGIC = getMagicNumber("Resource".getBytes());
48  
49      private static final int NULL_NAME = getMagicNumber("null name".getBytes());
50  
51      /**
52       * Create a "magic number" for use in hashCode calculations.
53       * @param seed byte[] to seed with.
54       * @return a magic number as int.
55       */
56      protected static int getMagicNumber(byte[] seed) {
57          return new BigInteger  (seed).intValue();
58      }
59  
60      private String   name = null;
61      private Boolean   exists = null;
62      private Long   lastmodified = null;
63      private Boolean   directory = null;
64      private Long   size = null;
65  
66      /**
67       * Default constructor.
68       */
69      public Resource() {
70      }
71  
72      /**
73       * Only sets the name.
74       *
75       * <p>This is a dummy, used for not existing resources.</p>
76       *
77       * @param name relative path of the resource.  Expects
78       * &quot;/&quot; to be used as the directory separator.
79       */
80      public Resource(String   name) {
81          this(name, false, 0, false);
82      }
83  
84      /**
85       * Sets the name, lastmodified flag, and exists flag.
86       *
87       * @param name relative path of the resource.  Expects
88       * &quot;/&quot; to be used as the directory separator.
89       * @param exists if true, this resource exists.
90       * @param lastmodified the last modification time of this resource.
91       */
92      public Resource(String   name, boolean exists, long lastmodified) {
93          this(name, exists, lastmodified, false);
94      }
95  
96      /**
97       * Sets the name, lastmodified flag, exists flag, and directory flag.
98       *
99       * @param name relative path of the resource.  Expects
100      * &quot;/&quot; to be used as the directory separator.
101      * @param exists if true the resource exists
102      * @param lastmodified the last modification time of the resource
103      * @param directory    if true, this resource is a directory
104      */
105     public Resource(String   name, boolean exists, long lastmodified,
106                     boolean directory) {
107         this(name, exists, lastmodified, directory, UNKNOWN_SIZE);
108     }
109 
110     /**
111      * Sets the name, lastmodified flag, exists flag, directory flag, and size.
112      *
113      * @param name relative path of the resource.  Expects
114      * &quot;/&quot; to be used as the directory separator.
115      * @param exists if true the resource exists
116      * @param lastmodified the last modification time of the resource
117      * @param directory    if true, this resource is a directory
118      * @param size the size of this resource.
119      */
120     public Resource(String   name, boolean exists, long lastmodified,
121                     boolean directory, long size) {
122         this.name = name;
123         setName(name);
124         setExists(exists);
125         setLastModified(lastmodified);
126         setDirectory(directory);
127         setSize(size);
128     }
129 
130     /**
131      * Name attribute will contain the path of a file relative to the
132      * root directory of its fileset or the recorded path of a zip
133      * entry.
134      *
135      * <p>example for a file with fullpath /var/opt/adm/resource.txt
136      * in a file set with root dir /var/opt it will be
137      * adm/resource.txt.</p>
138      *
139      * <p>&quot;/&quot; will be used as the directory separator.</p>
140      * @return the name of this resource.
141      */
142     public String   getName() {
143         return isReference() ? ((Resource) getCheckedRef()).getName() : name;
144     }
145 
146     /**
147      * Set the name of this Resource.
148      * @param name relative path of the resource.  Expects
149      * &quot;/&quot; to be used as the directory separator.
150      */
151     public void setName(String   name) {
152         checkAttributesAllowed();
153         this.name = name;
154     }
155 
156     /**
157      * The exists attribute tells whether a file exists.
158      * @return true if this resource exists.
159      */
160     public boolean isExists() {
161         if (isReference()) {
162             return ((Resource) getCheckedRef()).isExists();
163         }
164         //default true:
165         return exists == null || exists.booleanValue();
166     }
167 
168     /**
169      * Set the exists attribute.
170      * @param exists if true, this resource exists.
171      */
172     public void setExists(boolean exists) {
173         checkAttributesAllowed();
174         this.exists = exists ? Boolean.TRUE : Boolean.FALSE;
175     }
176 
177     /**
178      * Tells the modification time in milliseconds since 01.01.1970 .
179      *
180      * @return 0 if the resource does not exist to mirror the behavior
181      * of {@link java.io.File File}.
182      */
183     public long getLastModified() {
184         if (isReference()) {
185             return ((Resource) getCheckedRef()).getLastModified();
186         }
187         if (!isExists() || lastmodified == null) {
188             return UNKNOWN_DATETIME;
189         }
190         long result = lastmodified.longValue();
191         return result < UNKNOWN_DATETIME ? UNKNOWN_DATETIME : result;
192     }
193 
194     /**
195      * Set the last modification attribute.
196      * @param lastmodified the modification time in milliseconds since 01.01.1970.
197      */
198     public void setLastModified(long lastmodified) {
199         checkAttributesAllowed();
200         this.lastmodified = new Long  (lastmodified);
201     }
202 
203     /**
204      * Tells if the resource is a directory.
205      * @return boolean flag indicating if the resource is a directory.
206      */
207     public boolean isDirectory() {
208         if (isReference()) {
209             return ((Resource) getCheckedRef()).isDirectory();
210         }
211         //default false:
212         return directory != null && directory.booleanValue();
213     }
214 
215     /**
216      * Set the directory attribute.
217      * @param directory if true, this resource is a directory.
218      */
219     public void setDirectory(boolean directory) {
220         checkAttributesAllowed();
221         this.directory = directory ? Boolean.TRUE : Boolean.FALSE;
222     }
223 
224     /**
225      * Set the size of this Resource.
226      * @param size the size, as a long.
227      * @since Ant 1.6.3
228      */
229     public void setSize(long size) {
230         checkAttributesAllowed();
231         this.size = new Long  (size > UNKNOWN_SIZE ? size : UNKNOWN_SIZE);
232     }
233 
234     /**
235      * Get the size of this Resource.
236      * @return the size, as a long, 0 if the Resource does not exist (for
237      *         compatibility with java.io.File), or UNKNOWN_SIZE if not known.
238      * @since Ant 1.6.3
239      */
240     public long getSize() {
241         if (isReference()) {
242             return ((Resource) getCheckedRef()).getSize();
243         }
244         return isExists()
245             ? (size != null ? size.longValue() : UNKNOWN_SIZE)
246             : 0L;
247     }
248 
249     /**
250      * Clone this Resource.
251      * @return copy of this.
252      */
253     public Object   clone() {
254         try {
255             return super.clone();
256         } catch (CloneNotSupportedException   e) {
257             throw new UnsupportedOperationException  (
258                     "CloneNotSupportedException for a Resource caught. "
259                     + "Derived classes must support cloning.");
260         }
261     }
262 
263     /**
264      * Delegates to a comparison of names.
265      * @param other the object to compare to.
266      * @return a negative integer, zero, or a positive integer as this Resource
267      *         is less than, equal to, or greater than the specified Resource.
268      * @since Ant 1.6
269      */
270     public int compareTo(Object   other) {
271         if (isReference()) {
272             return ((Comparable  ) getCheckedRef()).compareTo(other);
273         }
274         if (!(other instanceof Resource)) {
275             throw new IllegalArgumentException  (
276                 "Can only be compared with Resources");
277         }
278         return toString().compareTo(other.toString());
279     }
280 
281     /**
282      * Implement basic Resource equality.
283      * @param other the object to check against.
284      * @return true if the specified Object is equal to this Resource.
285      * @since Ant 1.7
286      */
287     public boolean equals(Object   other) {
288         if (isReference()) {
289             return getCheckedRef().equals(other);
290         }
291         return other.getClass().equals(getClass()) && compareTo(other) == 0;
292     }
293 
294     /**
295      * Get the hash code for this Resource.
296      * @return hash code as int.
297      * @since Ant 1.7
298      */
299     public int hashCode() {
300         if (isReference()) {
301             return getCheckedRef().hashCode();
302         }
303         String   name = getName();
304         return MAGIC * (name == null ? NULL_NAME : name.hashCode());
305     }
306 
307     /**
308      * Get an InputStream for the Resource.
309      * @return an InputStream containing this Resource's content.
310      * @throws IOException if unable to provide the content of this
311      *         Resource as a stream.
312      * @throws UnsupportedOperationException if InputStreams are not
313      *         supported for this Resource type.
314      * @since Ant 1.7
315      */
316     public InputStream   getInputStream() throws IOException   {
317         if (isReference()) {
318             return ((Resource) getCheckedRef()).getInputStream();
319         }
320         throw new UnsupportedOperationException  ();
321     }
322 
323     /**
324      * Get an OutputStream for the Resource.
325      * @return an OutputStream to which content can be written.
326      * @throws IOException if unable to provide the content of this
327      *         Resource as a stream.
328      * @throws UnsupportedOperationException if OutputStreams are not
329      *         supported for this Resource type.
330      * @since Ant 1.7
331      */
332     public OutputStream   getOutputStream() throws IOException   {
333         if (isReference()) {
334             return ((Resource) getCheckedRef()).getOutputStream();
335         }
336         throw new UnsupportedOperationException  ();
337     }
338 
339     /**
340      * Fulfill the ResourceCollection contract.
341      * @return an Iterator of Resources.
342      * @since Ant 1.7
343      */
344     public Iterator   iterator() {
345         return isReference() ? ((Resource) getCheckedRef()).iterator()
346             : new Iterator  () {
347             private boolean done = false;
348             public boolean hasNext() {
349                 return !done;
350             }
351             public Object   next() {
352                 if (done) {
353                     throw new NoSuchElementException  ();
354                 }
355                 done = true;
356                 return Resource.this;
357             }
358             public void remove() {
359                 throw new UnsupportedOperationException  ();
360             }
361         };
362     }
363 
364     /**
365      * Fulfill the ResourceCollection contract.
366      * @return the size of this ResourceCollection.
367      * @since Ant 1.7
368      */
369     public int size() {
370         return isReference() ? ((Resource) getCheckedRef()).size() : 1;
371     }
372 
373     /**
374      * Fulfill the ResourceCollection contract.
375      * @return whether this Resource is a FileResource.
376      * @since Ant 1.7
377      */
378     public boolean isFilesystemOnly() {
379         //default false:
380         return isReference() && ((Resource) getCheckedRef()).isFilesystemOnly();
381     }
382 
383     /**
384      * Get the string representation of this Resource.
385      * @return this Resource formatted as a String.
386      * @since Ant 1.7
387      */
388     public String   toString() {
389         if (isReference()) {
390             return getCheckedRef().toString();
391         }
392         String   n = getName();
393         return n == null ? "(anonymous)" : n;
394     }
395 
396     /**
397      * Get a long String representation of this Resource.
398      * This typically should be the value of <code>toString()</code>
399      * prefixed by a type description.
400      * @return this Resource formatted as a long String.
401      * @since Ant 1.7
402      */
403     public final String   toLongString() {
404         return isReference() ? ((Resource) getCheckedRef()).toLongString()
405             : getDataTypeName() + " \"" + toString() + '"';
406     }
407 
408     /**
409      * Overrides the base version.
410      * @param r the Reference to set.
411      */
412     public void setRefid(Reference r) {
413         if (name != null
414             || exists != null
415             || lastmodified != null
416             || directory != null
417             || size != null) {
418             throw tooManyAttributes();
419         }
420         super.setRefid(r);
421     }
422 
423 }
424
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