    001    //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.4_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    }