001    //$HeadURL: svn+ssh://jwilden@svn.wald.intevation.org/deegree/base/branches/2.5_testing/src/org/deegree/io/shpapi/IndexFile.java $
002    /*----------------------------------------------------------------------------
003     This file is part of deegree, http://deegree.org/
004     Copyright (C) 2001-2009 by:
005       Department of Geography, University of Bonn
006     and
007       lat/lon GmbH
008    
009     This library is free software; you can redistribute it and/or modify it under
010     the terms of the GNU Lesser General Public License as published by the Free
011     Software Foundation; either version 2.1 of the License, or (at your option)
012     any later version.
013     This library is distributed in the hope that it will be useful, but WITHOUT
014     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
015     FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
016     details.
017     You should have received a copy of the GNU Lesser General Public License
018     along with this library; if not, write to the Free Software Foundation, Inc.,
019     59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
020    
021     Contact information:
022    
023     lat/lon GmbH
024     Aennchenstr. 19, 53177 Bonn
025     Germany
026     http://lat-lon.de/
027    
028     Department of Geography, University of Bonn
029     Prof. Dr. Klaus Greve
030     Postfach 1147, 53001 Bonn
031     Germany
032     http://www.geographie.uni-bonn.de/deegree/
033    
034     e-mail: info@deegree.org
035    ----------------------------------------------------------------------------*/
036    
037    package org.deegree.io.shpapi;
038    
039    import java.io.File;
040    import java.io.FileOutputStream;
041    import java.io.IOException;
042    import java.io.RandomAccessFile;
043    import java.util.ArrayList;
044    
045    import org.deegree.model.spatialschema.ByteUtils;
046    
047    /**
048     * Class representing an ESRI Shape File.
049     * <p>
050     * Uses class ShapeUtils modified from the original package com.bbn.openmap.layer.shape <br>
051     * Copyright (C) 1998 BBN Corporation 10 Moulton St. Cambridge, MA 02138 <br>
052     *
053     *
054     * @version 31.07.2000
055     * @author Andreas Poth
056     */
057    
058    public class IndexFile {
059    
060        private static final String _shx = ".shx";
061    
062        private RandomAccessFile raf;
063    
064        /**
065         * The length of an index record. (8 byte)
066         */
067        private static final int INDEX_RECORD_LENGTH = 8;
068    
069        /**
070         * array which holds the content of .shx-file:
071         */
072        private IndexRecord[] indexArray = null;
073    
074        /**
075         * IndexFileHeader is equal to ShapeFileHeader
076         */
077        private FileHeader fh;
078    
079        /**
080         * minimum bounding rectangle of the shape-file
081         */
082        private SHPEnvelope fileMBR;
083    
084        /**
085         * number of Records in .shp, .shx., .dbf has to be identical
086         */
087        private int RecordNum;
088    
089        /**
090         * file position offset
091         */
092        private long offset;
093    
094        /**
095         * length of the indexfile
096         */
097        private int filelength = 0;
098    
099        /**
100         * Construct a IndexFile from a file name.
101         *
102         * @param url
103         * @throws IOException
104         */
105        public IndexFile( String url ) throws IOException {
106    
107            /*
108             * creates raf
109             */
110            raf = new RandomAccessFile( url + _shx, "r" );
111    
112            /*
113             * construct Header as ShapeFileHeader
114             */
115            fh = new FileHeader( raf );
116    
117            fileMBR = fh.getFileMBR();
118    
119            /*
120             * construct indexArray
121             */
122            setIndexArray();
123    
124        }
125    
126        /**
127         * Construct a IndexFile from a file name.
128         *
129         * @param url
130         * @param rwflag
131         * @throws IOException
132         */
133        public IndexFile( String url, String rwflag ) throws IOException {
134    
135            // delete file if it exists
136            File file = new File( url + _shx );
137            if ( rwflag.indexOf( 'w' ) > -1 && file.exists() ) {
138                file.delete();
139                FileOutputStream os = new FileOutputStream( file, false );
140                os.close();
141            }
142            file = null;
143            raf = new RandomAccessFile( url + _shx, rwflag );
144            // if the 2nd arg is true an empty header will be
145            // written by FileHeader
146            fh = new FileHeader( raf, rwflag.indexOf( 'w' ) > -1 );
147            fileMBR = fh.getFileMBR();
148            offset = raf.length();
149    
150            if ( offset < 100 ) {
151                offset = ShapeConst.SHAPE_FILE_HEADER_LENGTH;
152            }
153            setIndexArray();
154        }
155    
156        /**
157         *
158         */
159        public void close() {
160            try {
161                raf.close();
162            } catch ( Exception ex ) {
163                ex.printStackTrace();
164            }
165    
166        }
167    
168        /**
169         * method: writeHeader(int filelength, byte shptype,SHPEnvelope mbr) <BR>
170         * Writes a header into the index file. <BR>
171         *
172         * @param shptype
173         * @param mbr
174         * @throws IOException
175         */
176        public void writeHeader( int shptype, SHPEnvelope mbr )
177                                throws IOException {
178    
179            byte[] header = new byte[ShapeConst.SHAPE_FILE_HEADER_LENGTH];
180    
181            ByteUtils.writeBEInt( header, 0, ShapeConst.SHAPE_FILE_CODE );
182            ByteUtils.writeBEInt( header, 24, filelength );
183            ByteUtils.writeLEInt( header, 28, ShapeConst.SHAPE_FILE_VERSION );
184            ByteUtils.writeLEInt( header, 32, shptype );
185            ShapeUtils.writeBox( header, 36, mbr );
186    
187            raf.seek( 0 );
188            raf.write( header, 0, ShapeConst.SHAPE_FILE_HEADER_LENGTH );
189        }
190    
191        /**
192         * method: getFileMBR() <BR>
193         * returns the minimum bounding rectangle of the shape-file <BR>
194         *
195         * @return the minimum bounding rectangle of the shape-file <BR>
196         */
197        public SHPEnvelope getFileMBR() {
198    
199            return fileMBR;
200    
201        }
202    
203        /**
204         * method: setIndexArray() <BR>
205         * local constructor for local field indexArray <BR>
206         */
207        private void setIndexArray()
208                                throws IOException {
209    
210            byte[] recBuf = new byte[INDEX_RECORD_LENGTH];
211            long rafPos = ShapeConst.SHAPE_FILE_HEADER_LENGTH;
212            int iaIndex = 0;
213            ArrayList<IndexRecord> indexArrayVector = new ArrayList<IndexRecord>( 10000 );
214    
215            raf.seek( rafPos );
216            // loop over index records, until EOF
217            while ( raf.read( recBuf, 0, INDEX_RECORD_LENGTH ) != -1 ) {
218                IndexRecord ir = new IndexRecord( recBuf );
219    
220                // set ArrayVector item as index record
221                indexArrayVector.add( ir );
222    
223                // array index adjustment
224                ++iaIndex;
225    
226                // filepos adjustment
227                rafPos = rafPos + INDEX_RECORD_LENGTH;
228                raf.seek( rafPos );
229            } // end of while
230    
231            // iaIndex holds Record Number
232            RecordNum = iaIndex;
233    
234            // copy vector into indexArray
235            indexArray = indexArrayVector.toArray( new IndexRecord[RecordNum] );
236        }
237    
238        /**
239         * method: getIndexArray() <BR>
240         * clones local field indexArray <BR>
241         *
242         * @return the index record
243         */
244        public IndexRecord[] getIndexArray() {
245            return indexArray;
246        }
247    
248        /**
249         * method: getRecordNum() <BR>
250         * function to get number of Records <BR>
251         *
252         * @return number of Records <BR>
253         */
254        public int getRecordNum() {
255            return RecordNum;
256        }
257    
258        /**
259         * methode: getRecordOffset (int RecNo) <BR>
260         * function to get Record offset by Record number <BR>
261         *
262         * @param RecNo
263         * @return offset by Record number <BR>
264         */
265        public int getRecordOffset( int RecNo ) {
266            if ( RecNo >= 0 ) {
267                return indexArray[RecNo].offset;
268            }
269            return -1;
270        }
271    
272        /**
273         * method: getRecordLength (int RecNo) <BR>
274         * function to get Record Length by Record number <BR>
275         *
276         * @param RecNo
277         * @return Record Length by Record number <BR>
278         */
279        public int getRecordLength( int RecNo ) {
280            if ( RecNo >= 0 ) {
281                return indexArray[RecNo].length;
282            }
283            return -1;
284        }
285    
286        /**
287         * method: getIndexRecord (int RecNo) <BR>
288         * function to get Index Record by Record number <BR>
289         *
290         * @param RecNo
291         * @return Index Record by Record number <BR>
292         */
293        public IndexRecord getIndexRecord( int RecNo ) {
294            IndexRecord ir = new IndexRecord();
295            if ( RecNo >= 0 ) {
296                return ir = indexArray[RecNo];
297            }
298            return ir;
299        }
300    
301        /**
302         * appends an index record to the indexfile
303         *
304         * @param record
305         * @param mbr
306         * @throws IOException
307         */
308        public void appendRecord( IndexRecord record, SHPEnvelope mbr )
309                                throws IOException {
310            offset = raf.length();
311            raf.seek( offset );
312            raf.write( record.writeIndexRecord() );
313            offset = offset + INDEX_RECORD_LENGTH;
314            // actualize mbr
315            if ( fileMBR.west > mbr.west ) {
316                fileMBR.west = mbr.west;
317            }
318            if ( fileMBR.east < mbr.east ) {
319                fileMBR.east = mbr.east;
320            }
321            if ( fileMBR.south > mbr.south ) {
322                fileMBR.south = mbr.south;
323            }
324            if ( fileMBR.north < mbr.north ) {
325                fileMBR.north = mbr.north;
326            }
327            raf.seek( 36 );
328            raf.write( fileMBR.writeLESHPEnvelope() );
329    
330            // actualize file length
331            filelength = (int) offset / 2;
332        }
333    }