/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.data.postgis.attributeio;
import java.io.IOException;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import org.geotools.data.DataSourceException;
import org.geotools.data.jdbc.attributeio.AttributeIO;
import org.geotools.factory.Hints;
import org.geotools.geometry.jts.LiteCoordinateSequenceFactory;
import com.vividsolutions.jts.geom.CoordinateSequenceFactory;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.PrecisionModel;
import com.vividsolutions.jts.geom.impl.CoordinateArraySequenceFactory;
import com.vividsolutions.jts.io.InStream;
import com.vividsolutions.jts.io.WKBReader;
import com.vividsolutions.jts.io.WKBWriter;
/**
* An attribute IO implementation that can manage the WKB
*
* @author Andrea Aime
*
*
* @source $URL$
*/
public class PgWKBAttributeIO implements AttributeIO {
private boolean useByteArray;
// private GeometryFactory gf;
WKBReader wkbr;
ByteArrayInStream inStream = new ByteArrayInStream();
public PgWKBAttributeIO(boolean useByteArray) {
this.useByteArray = useByteArray;
wkbr = new WKBReader();
}
public PgWKBAttributeIO(boolean useByteArray, Hints hints) {
this.useByteArray = useByteArray;
// setup the geometry factory according to the hints
GeometryFactory gf = (GeometryFactory) hints.get(Hints.JTS_GEOMETRY_FACTORY);
if(gf == null) {
PrecisionModel pm = (PrecisionModel) hints.get(Hints.JTS_PRECISION_MODEL);
if(pm == null)
pm = new PrecisionModel();
Integer SRID = (Integer) hints.get(Hints.JTS_SRID);
int srid = SRID == null ? 0 : SRID.intValue();
Integer dimension = (Integer) hints.get(Hints.COORDINATE_DIMENSION);
CoordinateSequenceFactory csFactory = (CoordinateSequenceFactory) hints.get(Hints.JTS_COORDINATE_SEQUENCE_FACTORY);
if(csFactory == null) {
if(dimension == null || dimension <= 3) {
csFactory = CoordinateArraySequenceFactory.instance();
} else {
csFactory = new LiteCoordinateSequenceFactory();
}
}
gf = new GeometryFactory(pm, srid, csFactory);
}
wkbr = new WKBReader(gf);
}
/**
* Turns a char that encodes four bits in hexadecimal notation into a byte
*
* @param c
*
*/
public static byte getFromChar(char c) {
if (c <= '9') {
return (byte) (c - '0');
} else if (c <= 'F') {
return (byte) (c - 'A' + 10);
} else {
return (byte) (c - 'a' + 10);
}
}
/**
* This method will convert a String of hex characters that represent the
* hexadecimal form of a Geometry in Well Known Binary representation to a
* JTS Geometry object.
*
* @param wkb a String of hex characters where each character represents a
* hex value. In particular, each character is a value of 0-9, A, B
* ,C, D, E, or F.
*
* @return a JTS Geometry object that is equivalent to the WTB
* representation passed in by param wkb
*
* @throws IOException if more than one geometry object was found in the
* WTB representation, or if the parser could not parse the WKB
* representation.
*/
private Geometry WKB2Geometry(byte[] wkbBytes)
throws IOException {
// convert the byte[] to a JTS Geometry object
if (wkbBytes == null) //DJB: null value from database --> null geometry (the same behavior as WKT). NOTE: sending back a GEOMETRYCOLLECTION(EMPTY) is also a possibility, but this is not the same as NULL
return null;
try {
inStream.setBytes(wkbBytes);
return wkbr.read(inStream);
} catch (Exception e) {
throw new DataSourceException("An exception occurred while parsing WKB data", e);
}
// JTSFactory factory = new JTSFactory();
// WKBParser parser = new WKBParser(factory);
// try {
// parser.parseData(wkbBytes, 42102);
// } catch (Exception e) {
// throw new DataSourceException("An exception occurred while parsing WKB data", e);
// }
// ArrayList geoms = factory.getGeometries();
//
// if (geoms.size() > 0) {
// return (Geometry) geoms.get(0);
// } else if (geoms.size() > 1) {
// throw new IOException(
// "Found more than one Geometry in WKB representation ");
// } else {
// throw new IOException(
// "Could not parse WKB representations - found no Geometries ");
// }
}
private byte[] hexToBytes(String wkb) {
// convert the String of hex values to a byte[]
byte[] wkbBytes = new byte[wkb.length() / 2];
for (int i = 0; i < wkbBytes.length; i++) {
byte b1 = getFromChar(wkb.charAt(i * 2));
byte b2 = getFromChar(wkb.charAt((i * 2) + 1));
wkbBytes[i] = (byte) ((b1 << 4) | b2);
}
return wkbBytes;
}
/*
private byte[] byteaToBytes(byte[] bytes) {
for(int i = 0; i < bytes.length; i++) {
if(bytes[i] >= 'A')
bytes[i] -= ('A' + 10);
else
bytes[i] -= '0';
}
return bytes;
}
*/
public void compare(byte[] b1, byte[] b2)
{
int len = b2.length;
for (int t=0;t<len;t++)
{
if (b1[t] != b2[t])
System.out.println("differ at position "+t+ "("+b1[t]+" vs "+b2[t]+")");
}
}
/**
* @see org.geotools.data.jdbc.attributeio.AttributeIO#read(java.sql.ResultSet,
* int)
*/
public Object read(ResultSet rs, int position) throws IOException {
try {
if(useByteArray) {
byte bytes[] = rs.getBytes(position);
// byte b[] = Base64.decode(bytes);
// byte b2[] = Base64.decode(bytes,0,bytes.length);
// compare(b,b2);
if (bytes == null) // ie. its a null column -> return a null geometry!
return null;
return WKB2Geometry(Base64.decode(bytes));
// return WKB2Geometry(bytes);
} else {
return WKB2Geometry(hexToBytes(rs.getString(position)));
}
} catch (SQLException e) {
throw new DataSourceException("SQL exception occurred while reading the geometry.", e);
}
}
/**
* @param metaData
* @throws SQLException
*
private void printMetadata(ResultSetMetaData md) throws SQLException {
for (int i = 1; i <= md.getColumnCount(); i++) {
System.out.println(i + " " + md.getColumnName(i) + " " + md.getColumnTypeName(i));
}
}*/
/**
* Unsupported, will throw an UnsupportedOperationException
* @see org.geotools.data.jdbc.attributeio.AttributeIO#write(java.sql.ResultSet,
* int, java.lang.Object)
*/
public void write(ResultSet rs, int position, Object value)
throws IOException {
try {
if(value == null) {
rs.updateNull(position);
} else {
//rs.updateString(position, WKBEncoder.encodeGeometryHex((Geometry) value));
rs.updateBytes( position, new WKBWriter().write( (Geometry)value ));
}
} catch (SQLException e) {
throw new DataSourceException("SQL exception occurred while reading the geometry.", e);
}
}
/**
* @see org.geotools.data.jdbc.attributeio.AttributeIO#write(java.sql.PreparedStatement, int, java.lang.Object)
*/
public void write(PreparedStatement ps, int position, Object value) throws IOException {
try {
if(value == null) {
ps.setNull(position, Types.OTHER);
} else {
//ps.setString(position, WKBEncoder.encodeGeometryHex((Geometry) value));
ps.setBytes( position, new WKBWriter().write( (Geometry)value ));
}
} catch (SQLException e) {
throw new DataSourceException("SQL exception occurred while reading the geometry.", e);
}
}
private static class ByteArrayInStream implements InStream {
byte[] buffer;
int position;
public void setBytes(final byte[] buffer) {
this.buffer = buffer;
this.position = 0;
}
public void read(final byte[] buf) throws IOException {
final int size = buf.length;
System.arraycopy(buffer, position, buf, 0, size);
position += size;
}
}
}