1    
2    /* ====================================================================
3     * The Apache Software License, Version 1.1
4     *
5     * Copyright (c) 2002 The Apache Software Foundation.  All rights
6     * reserved.
7     *
8     * Redistribution and use in source and binary forms, with or without
9     * modification, are permitted provided that the following conditions
10    * are met:
11    *
12    * 1. Redistributions of source code must retain the above copyright
13    *    notice, this list of conditions and the following disclaimer.
14    *
15    * 2. Redistributions in binary form must reproduce the above copyright
16    *    notice, this list of conditions and the following disclaimer in
17    *    the documentation and/or other materials provided with the
18    *    distribution.
19    *
20    * 3. The end-user documentation included with the redistribution,
21    *    if any, must include the following acknowledgment:
22    *       "This product includes software developed by the
23    *        Apache Software Foundation (http://www.apache.org/)."
24    *    Alternately, this acknowledgment may appear in the software itself,
25    *    if and wherever such third-party acknowledgments normally appear.
26    *
27    * 4. The names "Apache" and "Apache Software Foundation" and
28    *    "Apache POI" must not be used to endorse or promote products
29    *    derived from this software without prior written permission. For
30    *    written permission, please contact apache@apache.org.
31    *
32    * 5. Products derived from this software may not be called "Apache",
33    *    "Apache POI", nor may "Apache" appear in their name, without
34    *    prior written permission of the Apache Software Foundation.
35    *
36    * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
37    * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
38    * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
39    * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
40    * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41    * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
42    * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
43    * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
44    * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
45    * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
46    * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47    * SUCH DAMAGE.
48    * ====================================================================
49    *
50    * This software consists of voluntary contributions made by many
51    * individuals on behalf of the Apache Software Foundation.  For more
52    * information on the Apache Software Foundation, please see
53    * <http://www.apache.org/>.
54    */
55   
56   package org.apache.poi.hssf.eventmodel;
57   
58   import java.io.InputStream;
59   import java.io.IOException;
60   
61   import org.apache.poi.util.LittleEndian;
62   import org.apache.poi.hssf.record.RecordFormatException;
63   import org.apache.poi.hssf.record.Record;
64   import org.apache.poi.hssf.record.RecordFactory;
65   import org.apache.poi.hssf.record.ContinueRecord;
66   import org.apache.poi.poifs.filesystem.POIFSFileSystem;
67   
68   /**
69    * Low level event based HSSF reader.  Pass either a DocumentInputStream to
70    * process events along with a request object or pass a POIFS POIFSFileSystem to
71    * processWorkbookEvents along with a request.
72    *
73    * This will cause your file to be processed a record at a time.  Each record with
74    * a static id matching one that you have registed in your HSSFRequest will be passed
75    * to your associated HSSFListener.
76    *
77    * @see org.apache.poi.hssf.dev.EFHSSF
78    *
79    * @author  andy
80    */
81   
82   public class HSSFEventFactory
83   {
84   
85       /** Creates a new instance of HSSFEventFactory */
86   
87       public HSSFEventFactory()
88       {
89       }
90   
91       /**
92        * Processes a file into essentially record events.
93        *
94        * @param req       an Instance of HSSFRequest which has your registered listeners
95        * @param fs        a POIFS filesystem containing your workbook
96        */
97   
98       public void processWorkbookEvents(HSSFRequest req, POIFSFileSystem fs)
99           throws IOException
100      {
101          InputStream in = fs.createDocumentInputStream("Workbook");
102  
103          processEvents(req, in);
104      }
105  
106      /**
107       * Processes a DocumentInputStream into essentially Record events.
108       *
109       * @see org.apache.poi.poifs.filesystem.POIFSFileSystem#createDocumentInputStream(String)
110       * @param req       an Instance of HSSFRequest which has your registered listeners
111       * @param in        a DocumentInputStream obtained from POIFS's POIFSFileSystem object
112       */
113  
114      public void processEvents(HSSFRequest req, InputStream in)
115          throws IOException
116      {
117          try
118          {
119              byte[] sidbytes  = new byte[ 2 ];
120              int    bytesread = in.read(sidbytes);
121              Record rec       = null;
122  
123              while (bytesread > 0)
124              {
125                  short sid = 0;
126  
127                  sid = LittleEndian.getShort(sidbytes);
128                  if ((rec != null) && (sid != ContinueRecord.sid))
129                  {
130                      req.processRecord(rec);
131                  }
132                  if (sid != ContinueRecord.sid)
133                  {
134                      short  size = LittleEndian.readShort(in);
135                      byte[] data = new byte[ size ];
136  
137                      if (data.length > 0)
138                      {
139                          in.read(data);
140                      }
141                      Record[] recs = RecordFactory.createRecord(sid, size,
142                                                                 data);
143  
144                      if (recs.length > 1)
145                      {                                // we know that the multiple
146                          for (int k = 0; k < (recs.length - 1); k++)
147                          {                            // record situations do not
148                              req.processRecord(
149                                  recs[ k ]);          // contain continue records
150                          }
151                      }
152                      rec = recs[ recs.length - 1 ];   // regardless we'll process
153  
154                      // the last record as though
155                      // it might be continued
156                      // if there is only one
157                      // records, it will go here too.
158                  }
159                  else
160                  {                                    // we do have a continue record
161                      short  size = LittleEndian.readShort(in);
162                      byte[] data = new byte[ size ];
163  
164                      if (data.length > 0)
165                      {
166                          in.read(data);
167                      }
168                      rec.processContinueRecord(data);
169                  }
170                  bytesread = in.read(sidbytes);       // read next record sid
171              }
172              if (rec != null)
173              {
174                  req.processRecord(rec);
175              }
176          }
177          catch (IOException e)
178          {
179              throw new RecordFormatException("Error reading bytes");
180          }
181  
182          // Record[] retval = new Record[ records.size() ];
183          // retval = ( Record [] ) records.toArray(retval);
184          // return null;
185      }
186  }
187