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1   package org.apache.maven.doxia.macro.snippet;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import org.apache.maven.doxia.macro.AbstractMacro;
23  import org.apache.maven.doxia.macro.Macro;
24  import org.apache.maven.doxia.macro.MacroExecutionException;
25  import org.apache.maven.doxia.macro.MacroRequest;
26  import org.apache.maven.doxia.sink.Sink;
27  import org.apache.maven.doxia.sink.SinkEventAttributeSet;
28  import org.codehaus.plexus.component.annotations.Component;
29  import org.codehaus.plexus.util.StringUtils;
30  
31  import java.io.File;
32  import java.io.IOException;
33  import java.net.MalformedURLException;
34  import java.net.URL;
35  import java.util.HashMap;
36  import java.util.Map;
37  
38  /**
39   * A macro that prints out the content of a file or a URL.
40   *
41   * @version $Id: SnippetMacro.java 1543585 2013-11-19 21:37:30Z michaelo $
42   */
43  @Component( role = Macro.class, hint = "snippet" )
44  public class SnippetMacro
45      extends AbstractMacro
46  {
47      /**
48       * Holds the cache.
49       */
50      private static Map<String, String> cache = new HashMap<String, String>();
51  
52      private static final int HOUR = 60;
53  
54      /**
55       * One hour default cache.
56       */
57      private long timeout = HOUR * HOUR * 1000;
58  
59      /**
60       * Holds the time cache.
61       */
62      private static Map<String, Long> timeCached = new HashMap<String, Long>();
63  
64      /**
65       * Debug.
66       */
67      private boolean debug = false;
68  
69      /**
70       * in case of Exception during snippet download error will ignored and empty content returned.
71       */
72      private boolean ignoreDownloadError;
73  
74      /**
75       * {@inheritDoc}
76       */
77      public void execute( Sink sink, MacroRequest request )
78          throws MacroExecutionException
79      {
80          String id = (String) request.getParameter( "id" );
81  
82          String urlParam = (String) request.getParameter( "url" );
83  
84          String fileParam = (String) request.getParameter( "file" );
85  
86          String debugParam = (String) request.getParameter( "debug" );
87  
88          if ( debugParam != null )
89          {
90              this.debug = Boolean.parseBoolean( debugParam );
91          }
92  
93          String ignoreDownloadErrorParam = (String) request.getParameter( "ignoreDownloadError" );
94  
95          if ( ignoreDownloadErrorParam != null )
96          {
97              this.ignoreDownloadError = Boolean.parseBoolean( ignoreDownloadErrorParam );
98          }
99  
100         boolean verbatim = true;
101 
102         String verbatimParam = (String) request.getParameter( "verbatim" );
103 
104         if ( verbatimParam != null && !"".equals( verbatimParam ) )
105         {
106             verbatim = Boolean.valueOf( verbatimParam ).booleanValue();
107         }
108 
109         String encoding = (String) request.getParameter( "encoding" );
110 
111         URL url;
112 
113         if ( !StringUtils.isEmpty( urlParam ) )
114         {
115             try
116             {
117                 url = new URL( urlParam );
118             }
119             catch ( MalformedURLException e )
120             {
121                 throw new IllegalArgumentException( urlParam + " is a malformed URL" );
122             }
123         }
124         else if ( !StringUtils.isEmpty( fileParam ) )
125         {
126             File f = new File( fileParam );
127 
128             if ( !f.isAbsolute() )
129             {
130                 f = new File( request.getBasedir(), fileParam );
131             }
132 
133             try
134             {
135                 url = f.toURI().toURL();
136             }
137             catch ( MalformedURLException e )
138             {
139                 throw new IllegalArgumentException( fileParam + " is a malformed URL" );
140             }
141         }
142         else
143         {
144             throw new IllegalArgumentException( "Either the 'url' or the 'file' param has to be given." );
145         }
146 
147         StringBuffer snippet;
148 
149         try
150         {
151             snippet = getSnippet( url, encoding, id );
152         }
153         catch ( IOException e )
154         {
155             throw new MacroExecutionException( "Error reading snippet", e );
156         }
157 
158         if ( verbatim )
159         {
160             sink.verbatim( SinkEventAttributeSet.BOXED );
161 
162             sink.text( snippet.toString() );
163 
164             sink.verbatim_();
165         }
166         else
167         {
168             sink.rawText( snippet.toString() );
169         }
170     }
171 
172     /**
173      * Return a snippet of the given url.
174      *
175      * @param url The URL to parse.
176      * @param encoding The encoding of the URL to parse.
177      * @param id  The id of the snippet.
178      * @return The snippet.
179      * @throws IOException if something goes wrong.
180      */
181     private StringBuffer getSnippet( URL url, String encoding, String id )
182         throws IOException
183     {
184         StringBuffer result;
185 
186         String cachedSnippet = getCachedSnippet( url, id );
187 
188         if ( cachedSnippet != null )
189         {
190             result = new StringBuffer( cachedSnippet );
191 
192             if ( debug )
193             {
194                 result.append( "(Served from cache)" );
195             }
196         }
197         else
198         {
199             try
200             {
201                 result = new SnippetReader( url, encoding ).readSnippet( id );
202                 cacheSnippet( url, id, result.toString() );
203                 if ( debug )
204                 {
205                     result.append( "(Fetched from url, cache content " ).append( cache ).append( ")" );
206                 }
207             }
208             catch ( IOException e )
209             {
210                 result = new StringBuffer( "Error during retrieving content skip as ignoreDownloadError activated." );
211             }
212 
213 
214         }
215 
216         return result;
217     }
218 
219     /**
220      * Return a snippet from the cache.
221      *
222      * @param url The URL to parse.
223      * @param id  The id of the snippet.
224      * @return The snippet.
225      */
226     private String getCachedSnippet( URL url, String id )
227     {
228         if ( isCacheTimedout( url, id ) )
229         {
230             removeFromCache( url, id );
231         }
232         return cache.get( globalSnippetId( url, id ) );
233     }
234 
235     /**
236      * Return true if the snippet has been cached longer than
237      * the current timeout.
238      *
239      * @param url The URL to parse.
240      * @param id  The id of the snippet.
241      * @return True if timeout exceeded.
242      */
243     boolean isCacheTimedout( URL url, String id )
244     {
245         return timeInCache( url, id ) >= timeout;
246     }
247 
248     /**
249      * Return the time the snippet has been cached.
250      *
251      * @param url The URL to parse.
252      * @param id  The id of the snippet.
253      * @return The cache time.
254      */
255     long timeInCache( URL url, String id )
256     {
257         return System.currentTimeMillis() - getTimeCached( url, id );
258     }
259 
260     /**
261      * Return the absolute value of when the snippet has been cached.
262      *
263      * @param url The URL to parse.
264      * @param id  The id of the snippet.
265      * @return The cache time.
266      */
267     long getTimeCached( URL url, String id )
268     {
269         String globalId = globalSnippetId( url, id );
270 
271         return timeCached.containsKey( globalId ) ? timeCached.get( globalId ).longValue() : 0;
272     }
273 
274     /**
275      * Removes the snippet from the cache.
276      *
277      * @param url The URL to parse.
278      * @param id  The id of the snippet.
279      */
280     private void removeFromCache( URL url, String id )
281     {
282         String globalId = globalSnippetId( url, id );
283 
284         timeCached.remove( globalId );
285 
286         cache.remove( globalId );
287     }
288 
289     /**
290      * Return a global identifier for the snippet.
291      *
292      * @param url The URL to parse.
293      * @param id  The id of the snippet.
294      * @return An identifier, concatenated url and id,
295      *         or just url.toString() if id is empty or null.
296      */
297     private String globalSnippetId( URL url, String id )
298     {
299         if ( StringUtils.isEmpty( id ) )
300         {
301             return url.toString();
302         }
303 
304         return url + " " + id;
305     }
306 
307     /**
308      * Puts the given snippet into the cache.
309      *
310      * @param url     The URL to parse.
311      * @param id      The id of the snippet.
312      * @param content The content of the snippet.
313      */
314     public void cacheSnippet( URL url, String id, String content )
315     {
316         cache.put( globalSnippetId( url, id ), content );
317 
318         timeCached.put( globalSnippetId( url, id ), Long.valueOf( System.currentTimeMillis() ) );
319     }
320 
321     /**
322      * Set the cache timeout.
323      *
324      * @param time The timeout to set.
325      */
326     public void setCacheTimeout( int time )
327     {
328         this.timeout = time;
329     }
330 }