GetMethod


1   /*
2    * Copyright (C) 2005 Alfresco, Inc.
3    *
4    * Licensed under the Mozilla Public License version 1.1 
5    * with a permitted attribution clause. You may obtain a
6    * copy of the License at
7    *
8    *   http://www.alfresco.org/legal/license.txt
9    *
10   * Unless required by applicable law or agreed to in writing,
11   * software distributed under the License is distributed on an
12   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
13   * either express or implied. See the License for the specific
14   * language governing permissions and limitations under the
15   * License.
16   */
17  package org.alfresco.repo.webdav;
18  
19  import java.io.IOException  ;
20  import java.io.Writer  ;
21  import java.text.ParseException  ;
22  import java.text.SimpleDateFormat  ;
23  import java.util.ArrayList  ;
24  import java.util.Date  ;
25  import java.util.List  ;
26  import java.util.StringTokenizer  ;
27  
28  import javax.servlet.http.HttpServletResponse  ;
29  
30  import org.alfresco.i18n.I18NUtil;
31  import org.alfresco.repo.content.filestore.FileContentReader;
32  import org.alfresco.service.cmr.model.FileFolderService;
33  import org.alfresco.service.cmr.model.FileInfo;
34  import org.alfresco.service.cmr.model.FileNotFoundException;
35  import org.alfresco.service.cmr.repository.ContentReader;
36  import org.alfresco.service.cmr.repository.NodeRef;
37  import org.alfresco.service.cmr.repository.datatype.DefaultTypeConverter;
38  import org.alfresco.service.cmr.repository.datatype.TypeConverter;
39  
40  /**
41   * Implements the WebDAV GET method
42   * 
43   * @author gavinc
44   */
45  public class GetMethod extends WebDAVMethod
46  {
47      // Request parameters
48  
49      private ArrayList   ifMatchTags = null;
50      private ArrayList   ifNoneMatchTags = null;
51      private Date   m_ifModifiedSince = null;
52      private Date   m_ifUnModifiedSince = null;
53  
54      protected boolean m_returnContent = true;
55  
56      /**
57       * Default constructor
58       */
59      public GetMethod()
60      {
61      }
62  
63      /**
64       * Parse the request headers
65       * 
66       * @exception WebDAVServerException
67       */
68      protected void parseRequestHeaders() throws WebDAVServerException
69      {
70          // If the range header is present output a warning, add support later
71  
72          String   strRange = m_request.getHeader(WebDAV.HEADER_RANGE);
73  
74          if (strRange != null && strRange.length() > 0)
75          {
76              logger.warn("Range header (" + strRange + ") not supported");
77          }
78  
79          // Capture all the If headers, process later
80  
81          String   strIfMatch = m_request.getHeader(WebDAV.HEADER_IF_MATCH);
82  
83          if (strIfMatch != null && strIfMatch.length() > 0)
84          {
85              ifMatchTags = parseETags(strIfMatch);
86          }
87  
88          String   strIfNoneMatch = m_request.getHeader(WebDAV.HEADER_IF_NONE_MATCH);
89          if (strIfNoneMatch != null && strIfNoneMatch.length() > 0)
90          {
91              ifNoneMatchTags = parseETags(strIfNoneMatch);
92          }
93  
94          // Parse the dates
95  
96          SimpleDateFormat   dateFormat = new SimpleDateFormat  (WebDAV.HEADER_IF_DATE_FORMAT);
97          String   strIfModifiedSince = m_request.getHeader(WebDAV.HEADER_IF_MODIFIED_SINCE);
98  
99          if (strIfModifiedSince != null && strIfModifiedSince.length() > 0)
100         {
101             try
102             {
103                 m_ifModifiedSince = dateFormat.parse(strIfModifiedSince);
104             }
105             catch (ParseException   e)
106             {
107                 logger.warn("Failed to parse If-Modified-Since date of " + strIfModifiedSince);
108             }
109         }
110 
111         String   strIfUnModifiedSince = m_request.getHeader(WebDAV.HEADER_IF_UNMODIFIED_SINCE);
112         if (strIfUnModifiedSince != null && strIfUnModifiedSince.length() > 0)
113         {
114             try
115             {
116                 m_ifUnModifiedSince = dateFormat.parse(strIfUnModifiedSince);
117             }
118             catch (ParseException   e)
119             {
120                 logger.warn("Failed to parse If-Unmodified-Since date of " + strIfUnModifiedSince);
121             }
122         }
123     }
124 
125     /**
126      * Parse the request body
127      * 
128      * @exception WebDAVServerException
129      */
130     protected void parseRequestBody() throws WebDAVServerException
131     {
132         // Nothing to do in this method
133     }
134 
135     /**
136      * Exceute the WebDAV request
137      * 
138      * @exception WebDAVServerException
139      */
140     protected void executeImpl() throws WebDAVServerException, Exception  
141     {
142         FileFolderService fileFolderService = getFileFolderService();
143         NodeRef rootNodeRef = getRootNodeRef();
144         String   path = getPath();
145         String   servletPath = getServletPath();
146 
147         FileInfo nodeInfo = null;
148         try
149         {
150             nodeInfo = getDAVHelper().getNodeForPath(rootNodeRef, path, servletPath);
151         }
152         catch (FileNotFoundException e)
153         {
154             throw new WebDAVServerException(HttpServletResponse.SC_NOT_FOUND);
155         }
156         
157         // Check if the node is a folder
158         if (nodeInfo.isFolder())
159         {
160             // is content required
161             if (!m_returnContent)
162             {
163                 // it is a folder and no content is required
164                 throw new WebDAVServerException(HttpServletResponse.SC_BAD_REQUEST);
165             }
166             // Generate a folder listing
167             generateDirectoryListing(nodeInfo);
168         }
169         else
170         {
171             NodeRef pathNodeRef = nodeInfo.getNodeRef();
172             // Return the node details, and content if requested, check that the node passes the pre-conditions
173 
174             checkPreConditions(nodeInfo);
175 
176             // Build the response header
177             m_response.setHeader(WebDAV.HEADER_ETAG, getDAVHelper().makeQuotedETag(pathNodeRef));
178 
179             Date   modifiedDate = nodeInfo.getModifiedDate();
180             if (modifiedDate != null)
181             {
182                 long modDate = DefaultTypeConverter.INSTANCE.longValue(modifiedDate);
183                 m_response.setHeader(WebDAV.HEADER_LAST_MODIFIED, WebDAV.formatHeaderDate(modDate));
184             }
185 
186             ContentReader reader = fileFolderService.getReader(nodeInfo.getNodeRef());
187             // ensure that we generate something, even if the content is missing
188             reader = FileContentReader.getSafeContentReader(
189                     (ContentReader) reader,
190                     I18NUtil.getMessage(FileContentReader.MSG_MISSING_CONTENT),
191                     nodeInfo.getNodeRef(), reader);
192             // there is content associated with the node
193             m_response.setHeader(WebDAV.HEADER_CONTENT_LENGTH, "" + reader.getSize());
194             m_response.setHeader(WebDAV.HEADER_CONTENT_TYPE, reader.getMimetype());
195             
196             if (m_returnContent)
197             {
198                 // copy the content to the response output stream
199                 reader.getContent(m_response.getOutputStream());
200             }
201         }
202     }
203 
204     /**
205      * Checks the If header conditions
206      * 
207      * @param nodeInfo the node to check
208      * @throws WebDAVServerException if a pre-condition is not met
209      */
210     private void checkPreConditions(FileInfo nodeInfo) throws WebDAVServerException
211     {
212         // Make an etag for the node
213 
214         String   strETag = getDAVHelper().makeQuotedETag(nodeInfo.getNodeRef());
215         TypeConverter typeConv = DefaultTypeConverter.INSTANCE;
216 
217         // Check the If-Match header, don't send any content back if none of the tags in
218         // the list match the etag, and the wildcard is not present
219 
220         if (ifMatchTags != null)
221         {
222             if (ifMatchTags.contains(WebDAV.ASTERISK) == false && ifMatchTags.contains(strETag) == false)
223             {
224                 throw new WebDAVServerException(HttpServletResponse.SC_PRECONDITION_FAILED);
225             }
226         }
227 
228         // Check the If-None-Match header, don't send any content back if any of the tags
229         // in the list match the etag, or the wildcard is present
230 
231         if (ifNoneMatchTags != null)
232         {
233             if (ifNoneMatchTags.contains(WebDAV.ASTERISK) || ifNoneMatchTags.contains(strETag))
234             {
235                 throw new WebDAVServerException(HttpServletResponse.SC_NOT_MODIFIED);
236             }
237         }
238 
239         // Check the modified since list, if the If-None-Match header was not specified
240 
241         if (m_ifModifiedSince != null && ifNoneMatchTags == null)
242         {
243             Date   lastModifiedDate = nodeInfo.getModifiedDate();
244 
245             long fileLastModified = lastModifiedDate != null ? typeConv.longValue(lastModifiedDate) : 0L;
246             long modifiedSince = m_ifModifiedSince.getTime();
247 
248             if (fileLastModified != 0L && fileLastModified <= modifiedSince)
249             {
250                 throw new WebDAVServerException(HttpServletResponse.SC_NOT_MODIFIED);
251             }
252         }
253 
254         // Check the un-modified since list
255 
256         if (m_ifUnModifiedSince != null)
257         {
258             Date   lastModifiedDate = nodeInfo.getModifiedDate();
259 
260             long fileLastModified = lastModifiedDate != null ? typeConv.longValue(lastModifiedDate) : 0L;
261             long unModifiedSince = m_ifUnModifiedSince.getTime();
262 
263             if (fileLastModified >= unModifiedSince)
264             {
265                 throw new WebDAVServerException(HttpServletResponse.SC_PRECONDITION_FAILED);
266             }
267         }
268     }
269 
270     /**
271      * Parses the given ETag header into a list of separate ETags
272      * 
273      * @param strETagHeader The header to parse
274      * @return A list of ETags
275      */
276     private ArrayList   parseETags(String   strETagHeader)
277     {
278         ArrayList  <String  > list = new ArrayList  <String  >();
279 
280         StringTokenizer   tokenizer = new StringTokenizer  (strETagHeader, WebDAV.HEADER_VALUE_SEPARATOR);
281         while (tokenizer.hasMoreTokens())
282         {
283             list.add(tokenizer.nextToken().trim());
284         }
285 
286         return list;
287     }
288 
289     /**
290      * Generates a HTML representation of the contents of the path represented by the given node
291      * 
292      * @param fileInfo the file to use
293      */
294     private void generateDirectoryListing(FileInfo fileInfo)
295     {
296         FileFolderService fileFolderService = getFileFolderService();
297         Writer   writer = null;
298 
299         try
300         {
301             writer = m_response.getWriter();
302 
303             // Get the list of child nodes for the parent node
304             List  <FileInfo> childNodeInfos = fileFolderService.list(fileInfo.getNodeRef());
305 
306             // Send back the start of the HTML
307             writer.write("<html><head><title>Alfresco Content Repository</title>");
308             writer.write("<style>");
309             writer.write("body { font-family: Arial, Helvetica; font-size: 12pt; background-color: white; }\n");
310             writer.write("table { font-family: Arial, Helvetica; font-size: 12pt; background-color: white; }\n");
311             writer.write(".listingTable { border: solid black 1px; }\n");
312             writer.write(".textCommand { font-family: verdana; font-size: 10pt; }\n");
313             writer.write(".textLocation { font-family: verdana; font-size: 11pt; font-weight: bold; color: #2a568f; }\n");
314             writer.write(".textData { font-family: verdana; font-size: 10pt; }\n");
315             writer.write(".tableHeading { font-family: verdana; font-size: 10pt; font-weight: bold; color: white; background-color: #2a568f; }\n");
316             writer.write(".rowOdd { background-color: #eeeeee; }\n");
317             writer.write(".rowEven { background-color: #dddddd; }\n");
318             writer.write("</style></head>\n");
319             writer.flush();
320 
321             // Send back the table heading
322             writer.write("<body>\n");
323             writer.write("<table cellspacing='2' cellpadding='3' border='0' width='100%'>\n");
324             writer.write("<tr><td colspan='3' class='textLocation'>Directory listing for ");
325             writer.write(WebDAVHelper.encodeHTML(getPath()));
326             writer.write("</td></tr>\n");
327             writer.write("<tr><td height='10'></td></tr></table>");
328 
329             writer.write("<table cellspacing='2' cellpadding='3' border='0' width='100%' class='listingTable'>\n");
330             writer.write("<tr><td class='tableHeading' width='*'>Name</td>");
331             writer.write("<td class='tableHeading' width='10%'>Size</td>");
332             writer.write("<td class='tableHeading' width='20%'>Modified</td>");
333             writer.write("</tr>");
334 
335             // Get the URL for the root path
336             String   rootURL = WebDAV.getURLForPath(m_request, getPath(), true);
337             if (rootURL.endsWith(WebDAVHelper.PathSeperator) == false)
338             {
339                 rootURL = rootURL + WebDAVHelper.PathSeperator;
340             }
341 
342             // Start with a link to the parent folder so we can navigate back up, unless we are at the root level
343             if (fileInfo.getNodeRef().equals(getRootNodeRef()) == false)
344             {
345                 writer.write("<tr class='rowOdd'>");
346                 writer.write("<td class='textData'><a HREF=\"");
347 
348                 // Strip the last folder from the path
349 
350                 String  [] paths = getDAVHelper().splitPath(rootURL.substring(0, rootURL.length() - 1));
351                 writer.write(paths[0]);
352 
353                 writer.write("\">");
354                 writer.write("[Up a level]</a>");
355                 writer.write("</tr>\n");
356             }
357 
358             // Send back what we have generated so far
359             writer.flush();
360             int rowId = 0;
361 
362             for (FileInfo childNodeInfo : childNodeInfos)
363             {
364                 // Output the details for the current node
365                 writer.write("<tr class='");
366                 if (rowId++ % 2 == 0)
367                 {
368                     writer.write("rowOdd");
369                 }
370                 else
371                 {
372                     writer.write("rowEven");
373                 }
374                 writer.write("'><td class='textData'><a HREF=\"");
375                 writer.write(rootURL);
376 
377                 String   fname = childNodeInfo.getName();
378 
379                 writer.write(WebDAVHelper.encodeURL(fname));
380                 writer.write("\">");
381                 writer.write(WebDAVHelper.encodeHTML(fname));
382                 writer.write("</a>");
383 
384                 writer.write("</td><td class='textData'>");
385                 if (fileInfo.isFolder())
386                 {
387                     writer.write(formatSize("0"));
388                 }
389                 else
390                 {
391                     ContentReader reader = fileFolderService.getReader(childNodeInfo.getNodeRef());
392                     long fsize = 0L;
393                     if ( reader != null)
394                     {
395                         fsize = reader.getSize();
396                     }
397                     writer.write(formatSize("" + fsize));
398                 }
399                 writer.write("</td><td class='textData'>");
400 
401                 Date   modifiedDate = childNodeInfo.getModifiedDate();
402                 if (modifiedDate != null)
403                 {
404                     writer.write(WebDAV.formatHeaderDate(DefaultTypeConverter.INSTANCE.longValue(modifiedDate)));
405                 }
406                 else
407                 {
408                     writer.write("");
409                 }
410                 writer.write("</td>");
411 
412                 writer.write("</tr>\n");
413                 writer.flush();
414             }
415         }
416         catch (Throwable   e)
417         {
418             logger.error(e);
419 
420             if (writer != null)
421             {
422                 try
423                 {
424                     writer.write("<table><tr><td style='color:red'>");
425                     writer.write("An error occurred whilst generating the directory listing, ");
426                     writer.write("please contact the system administrator.</td></tr></table>");
427                     writer.flush();
428                 }
429                 catch (IOException   ioe)
430                 {
431                 }
432             }
433         }
434     }
435 
436     /**
437      * Formats the given size for display in a directory listing
438      * 
439      * @param strSize The content size
440      * @return The formatted size
441      */
442     private String   formatSize(String   strSize)
443     {
444         String   strFormattedSize = strSize;
445 
446         int length = strSize.length();
447         if (length < 4)
448         {
449             strFormattedSize = strSize + " bytes";
450         }
451         else if (length >= 4 && length < 7)
452         {
453             String   strLeft = strSize.substring(0, length - 3);
454             String   strRight = strSize.substring(length - 3, length - 2);
455 
456             StringBuffer   buffer = new StringBuffer  (strLeft);
457             if (!strRight.equals("0"))
458             {
459                 buffer.append(".");
460                 buffer.append(strRight);
461             }
462             buffer.append(" Kb");
463 
464             strFormattedSize = buffer.toString();
465         }
466         else
467         {
468             String   strLeft = strSize.substring(0, length - 6);
469             String   strRight = strSize.substring(length - 6, length - 5);
470 
471             StringBuffer   buffer = new StringBuffer  (strLeft);
472             if (!strRight.equals("0"))
473             {
474                 buffer.append(".");
475                 buffer.append(strRight);
476             }
477             buffer.append(" Mb");
478 
479             strFormattedSize = buffer.toString();
480         }
481 
482         return strFormattedSize;
483     }
484 }
485
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