/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
* (C) Copyright IBM Corporation, 2005-2007. All rights reserved.
*
* 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.db2;
/**
* This is a modified JTS WKBReader suiting for DB2
*
* @author Christian Mueller
*
*/
import java.io.IOException;
import com.vividsolutions.jts.geom.*;
import com.vividsolutions.jts.io.ByteArrayInStream;
import com.vividsolutions.jts.io.ByteOrderDataInStream;
import com.vividsolutions.jts.io.ByteOrderValues;
import com.vividsolutions.jts.io.InStream;
import com.vividsolutions.jts.io.ParseException;
import com.vividsolutions.jts.io.WKBConstants;
/**
* @author Christian Mueller
*
* Version of JTS WKB Reader adjusted for DB2
*
* @see WKBReader for JTS Java Doc
*
*
*
* @source $URL$
*/
public class DB2WKBReader {
/**
* Converts a hexadecimal string to a byte array.
*
* @param hex a string containing hex digits
*/
public static byte[] hexToBytes(String hex)
{
int byteLen = hex.length() / 2;
byte[] bytes = new byte[byteLen];
for (int i = 0; i < hex.length() / 2; i++) {
int i2 = 2 * i;
if (i2 + 1 > hex.length())
throw new IllegalArgumentException("Hex string has odd length");
int nib1 = hexToInt(hex.charAt(i2));
int nib0 = hexToInt(hex.charAt(i2 + 1));
byte b = (byte) ((nib1 << 4) + (byte) nib0);
bytes[i] = b;
}
return bytes;
}
private static int hexToInt(char hex)
{
int nib = Character.digit(hex, 16);
if (nib < 0)
throw new IllegalArgumentException("Invalid hex digit: '" + hex + "'");
return nib;
}
private static final String INVALID_GEOM_TYPE_MSG
= "Invalid geometry type encountered in ";
private GeometryFactory factory;
private PrecisionModel precisionModel;
// default dimension - will be set on read
private int inputDimension = 2;
private int SRID = 0;
private ByteOrderDataInStream dis = new ByteOrderDataInStream();
private double[] ordValues;
public DB2WKBReader() {
this(new GeometryFactory());
}
public DB2WKBReader(GeometryFactory geometryFactory) {
this.factory = geometryFactory;
precisionModel = factory.getPrecisionModel();
}
/**
* Reads a single {@link Geometry} from a byte array.
*
* @param bytes the byte array to read from
* @return the geometry read
* @throws ParseException if a parse exception occurs
*/
public Geometry read(byte[] bytes) throws ParseException
{
// possibly reuse the ByteArrayInStream?
// don't throw IOExceptions, since we are not doing any I/O
try {
return read(new ByteArrayInStream(bytes));
}
catch (IOException ex) {
throw new RuntimeException("Unexpected IOException caught: " + ex.getMessage());
}
}
/**
* Reads a {@link Geometry} from an {@link InStream).
*
* @param is the stream to read from
* @return the Geometry read
* @throws IOException
* @throws ParseException
*/
public Geometry read(InStream is)
throws IOException, ParseException
{
dis.setInStream(is);
Geometry g = readGeometry();
setSRID(g);
return g;
}
private Geometry readGeometry()
throws IOException, ParseException
{
// determine byte order
byte byteOrder = dis.readByte();
// default is big endian
if (byteOrder == WKBConstants.wkbNDR)
dis.setOrder(ByteOrderValues.LITTLE_ENDIAN);
int geometryType = dis.readInt();
if (DB2WKBConstants.zTypes.contains(geometryType)) {
inputDimension=3;
if (geometryType==DB2WKBConstants.wkbPointZ) geometryType=DB2WKBConstants.wkbPoint2D;
if (geometryType==DB2WKBConstants.wkbOGCPointZ) geometryType=DB2WKBConstants.wkbPoint2D;
if (geometryType==DB2WKBConstants.wkbLineStringZ) geometryType=DB2WKBConstants.wkbLineString2D;
if (geometryType==DB2WKBConstants.wkbOGCLineStringZ) geometryType=DB2WKBConstants.wkbLineString2D;
if (geometryType==DB2WKBConstants.wkbPolygonZ) geometryType=DB2WKBConstants.wkbPolygon2D;
if (geometryType==DB2WKBConstants.wkbOGCPolygonZ) geometryType=DB2WKBConstants.wkbPolygon2D;
if (geometryType==DB2WKBConstants.wkbMultiPointZ) geometryType=DB2WKBConstants.wkbMultiPoint2D;
if (geometryType==DB2WKBConstants.wkbOGCMultiPointZ) geometryType=DB2WKBConstants.wkbMultiPoint2D;
if (geometryType==DB2WKBConstants.wkbMultiLineStringZ) geometryType=DB2WKBConstants.wkbMultiLineString2D;
if (geometryType==DB2WKBConstants.wkbOGCMultiLineStringZ) geometryType=DB2WKBConstants.wkbMultiLineString2D;
if (geometryType==DB2WKBConstants.wkbMultiPolygonZ) geometryType=DB2WKBConstants.wkbMultiPolygon2D;
if (geometryType==DB2WKBConstants.wkbOGCMultiPolygonZ) geometryType=DB2WKBConstants.wkbMultiPolygon2D;
if (geometryType==DB2WKBConstants.wkbGeomCollectionZ) geometryType=DB2WKBConstants.wkbGeomCollection2D;
if (geometryType==DB2WKBConstants.wkbOGCGeomCollectionZ) geometryType=DB2WKBConstants.wkbGeomCollection2D;
}
// only allocate ordValues buffer if necessary
if (ordValues == null || ordValues.length < inputDimension)
ordValues = new double[inputDimension];
switch (geometryType) {
case DB2WKBConstants.wkbPoint2D :
return readPoint();
case DB2WKBConstants.wkbLineString2D :
return readLineString();
case DB2WKBConstants.wkbPolygon2D :
return readPolygon();
case DB2WKBConstants.wkbMultiPoint2D :
return readMultiPoint();
case DB2WKBConstants.wkbMultiLineString2D :
return readMultiLineString();
case DB2WKBConstants.wkbMultiPolygon2D :
return readMultiPolygon();
case DB2WKBConstants.wkbGeomCollection2D :
return readGeometryCollection();
}
throw new ParseException("Unknown WKB type " + geometryType);
//return null;
}
/**
* Sets the SRID, if it was specified in the WKB
*
* @param g the geometry to update
* @return the geometry with an updated SRID value, if required
*/
private Geometry setSRID(Geometry g)
{
if (SRID != 0)
g.setSRID(SRID);
return g;
}
private Point readPoint() throws IOException
{
CoordinateSequence pts = readCoordinateSequence(1);
return factory.createPoint(pts);
}
private LineString readLineString() throws IOException
{
int size = dis.readInt();
CoordinateSequence pts = readCoordinateSequence(size);
return factory.createLineString(pts);
}
private LinearRing readLinearRing() throws IOException
{
int size = dis.readInt();
CoordinateSequence pts = readCoordinateSequence(size);
return factory.createLinearRing(pts);
}
private Polygon readPolygon() throws IOException
{
int numRings = dis.readInt();
LinearRing[] holes = null;
if (numRings > 1)
holes = new LinearRing[numRings - 1];
LinearRing shell = readLinearRing();
for (int i = 0; i < numRings - 1; i++) {
holes[i] = readLinearRing();
}
return factory.createPolygon(shell, holes);
}
private MultiPoint readMultiPoint() throws IOException, ParseException
{
int numGeom = dis.readInt();
Point[] geoms = new Point[numGeom];
for (int i = 0; i < numGeom; i++) {
Geometry g = readGeometry();
if (! (g instanceof Point))
throw new ParseException(INVALID_GEOM_TYPE_MSG + "MultiPoint");
geoms[i] = (Point) g;
}
return factory.createMultiPoint(geoms);
}
private MultiLineString readMultiLineString() throws IOException, ParseException
{
int numGeom = dis.readInt();
LineString[] geoms = new LineString[numGeom];
for (int i = 0; i < numGeom; i++) {
Geometry g = readGeometry();
if (! (g instanceof LineString))
throw new ParseException(INVALID_GEOM_TYPE_MSG + "MultiLineString");
geoms[i] = (LineString) g;
}
return factory.createMultiLineString(geoms);
}
private MultiPolygon readMultiPolygon() throws IOException, ParseException
{
int numGeom = dis.readInt();
Polygon[] geoms = new Polygon[numGeom];
for (int i = 0; i < numGeom; i++) {
Geometry g = readGeometry();
if (! (g instanceof Polygon))
throw new ParseException(INVALID_GEOM_TYPE_MSG + "MultiPolygon");
geoms[i] = (Polygon) g;
}
return factory.createMultiPolygon(geoms);
}
private GeometryCollection readGeometryCollection() throws IOException, ParseException
{
int numGeom = dis.readInt();
Geometry[] geoms = new Geometry[numGeom];
for (int i = 0; i < numGeom; i++) {
geoms[i] = readGeometry();
}
return factory.createGeometryCollection(geoms);
}
private CoordinateSequence readCoordinateSequence(int size) throws IOException
{
CoordinateSequence seq = factory.getCoordinateSequenceFactory().create(size, inputDimension);
int targetDim = seq.getDimension();
if (targetDim > inputDimension)
targetDim = inputDimension;
for (int i = 0; i < size; i++) {
readCoordinate();
for (int j = 0; j < targetDim; j++) {
seq.setOrdinate(i, j, ordValues[j]);
}
}
return seq;
}
/**
* Reads a coordinate value with the specified dimensionality.
* Makes the X and Y ordinates precise according to the precision model
* in use.
*/
private void readCoordinate() throws IOException
{
for (int i = 0; i < inputDimension; i++) {
if (i <= 1) {
ordValues[i] = precisionModel.makePrecise(dis.readDouble());
}
else {
ordValues[i] = dis.readDouble();
}
}
}
}