1    
2    /* ====================================================================
3     * The Apache Software License, Version 1.1
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13    *    notice, this list of conditions and the following disclaimer.
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15    * 2. Redistributions in binary form must reproduce the above copyright
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21    *    if any, must include the following acknowledgment:
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55   
56   package org.apache.poi.hssf.record;
57   
58   /**
59    * Title: Record
60    * Description: All HSSF Records inherit from this class.  It
61    *              populates the fields common to all records (id, size and data).
62    *              Subclasses should be sure to validate the id,
63    * Company:
64    * @author Andrew C. Oliver
65    * @author Marc Johnson (mjohnson at apache dot org)
66    * @author Jason Height (jheight at chariot dot net dot au)
67    * @version 2.0-pre
68    */
69   
70   public abstract class Record
71   {
72   
73       /**
74        * The static ID, subclasses should override this value with the id for the
75        * record type they handle.
76        */
77   
78       public short   sid  = 0;
79       private short  id   = 0;
80       private short  size = 0;
81       private byte[] data = null;
82   
83       /**
84        * instantiates a blank record strictly for ID matching
85        */
86   
87       public Record()
88       {
89       }
90   
91       /**
92        * Constructor Record
93        *
94        * @param id record id
95        * @param size record size
96        * @param data raw data
97        */
98   
99       public Record(short id, short size, byte [] data)
100      {
101          this.id   = id;
102          this.size = size;
103          this.data = data;
104          validateSid(id);
105          fillFields(data, size);
106      }
107  
108      /**
109       * Constructor Record
110       *
111       * @param id record id
112       * @param size record size
113       * @param data raw data
114       */
115  
116      public Record(short id, short size, byte [] data, int offset)
117      {
118          this.id   = id;
119          this.size = size;
120          this.data = data;
121          validateSid(id);
122          fillFields(data, size, offset);
123      }
124  
125      /**
126       * called by constructor, should throw runtime exception in the event of a
127       * record passed with a differing ID.
128       *
129       * @param id alleged id for this record
130       */
131  
132      protected abstract void validateSid(short id);
133  
134      /**
135       * called by the constructor, should set class level fields.  Should throw
136       * runtime exception for bad/icomplete data.
137       *
138       * @param data raw data
139       */
140  
141      protected void fillFields(byte [] data, short size)
142      {
143          fillFields(data, size, 0);
144      }
145  
146      /**
147       * called by the constructor, should set class level fields.  Should throw
148       * runtime exception for bad/icomplete data.
149       *
150       * @param data raw data
151       * @param size size of data
152       * @param offset of the record's data (provided a big array of the file)
153       */
154  
155      protected abstract void fillFields(byte [] data, short size, int offset);
156  
157      /**
158       * called by the class that is responsible for writing this sucker.
159       * Subclasses should implement this so that their data is passed back in a
160       * byte array.
161       *
162       * @return byte array containing instance data
163       */
164  
165      public byte [] serialize()
166      {
167          byte[] retval = new byte[ getRecordSize() ];
168  
169          serialize(0, retval);
170          return retval;
171      }
172  
173      /**
174       * called by the class that is responsible for writing this sucker.
175       * Subclasses should implement this so that their data is passed back in a
176       * byte array.
177       *
178       * @param offset to begin writing at
179       * @param data byte array containing instance data
180       * @return number of bytes written
181       */
182  
183      public abstract int serialize(int offset, byte [] data);
184  
185      /**
186       * gives the current serialized size of the record. Should include the sid and reclength (4 bytes).
187       */
188  
189      public int getRecordSize()
190      {
191  
192          // this is kind od a stupid way to do it but for now we just serialize
193          // the record and return the size of the byte array
194          return serialize().length;
195      }
196  
197      /**
198       * tells whether this type of record contains a value
199       */
200  
201      public boolean isValue()
202      {
203          return false;
204      }
205  
206      /**
207       * DBCELL, ROW, VALUES all say yes
208       */
209  
210      public boolean isInValueSection()
211      {
212          return false;
213      }
214  
215      /**
216       * get a string representation of the record (for biffview/debugging)
217       */
218  
219      public String toString()
220      {
221          return super.toString();
222      }
223  
224      /**
225       * Process a continuation record; default handling is to ignore
226       * it -- TODO add logging
227       *
228       * @param record the continuation record's data
229       */
230  
231      // made public to satisfy biffviewer
232  
233      /* protected */
234      public void processContinueRecord(byte [] record)
235      {
236  
237          // System.out.println("Got a continue record ... NOW what??");
238      }
239  
240      /**
241       * return the non static version of the id for this record.
242       */
243  
244      public abstract short getSid();
245  
246      public Object clone() {
247        throw new RuntimeException("The class "+getClass().getName()+" needs to define a clone method");
248      }
249  }
250