001 //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.3_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 }