org.wkb4j.engine
Class WKBParser

java.lang.Object
  |
  +--org.wkb4j.engine.WKBParser

All Implemented Interfaces:

WKBGeometryTypes

Direct Known Subclasses:

WKBParser3D

public class WKBParser

extends java.lang.Object

implements WKBGeometryTypes

Generate events from the submitted array of bytes holding binary data in the Well-Known Binary format. It generates a beginGeometry event when it sees the beginning of a given Geometry, an endGeometry event when it sees the end of a given Geometry, and an abortGeometry event if something happens that makes the completion of the current Geometry impossible.
Points are treated differently from other Geometries: all the points in a Geometry are collected into a single array of byte and passed to the WKBFactory all at once. Events are nested, meaning that for a classical MultiLineString element with two LineStrings made of respectively 3 and 2 Points each, the following events will occur:

• beginWork()
• ...
• beginUnit()
  • beginMultiLineString(2)
    • beginLineString(3)
    • addPoints(points)
    • endLineString()
    • beginLineString(2)
    • addPoints(points)
    • endLineString()
  • endMultiLineString()
• endUnit()
• ...
• endWork()

The basic idea is to provide the author of each factory with as much freedom as possible while allowing for strong performance. wkbByteOrder aren't taken into account because will rely on the database to provide the data in the Big-Endian format (MSB, Most Significant Byte), the Endian used in Java.
Inspired by the SAX API.
Creation date: 6 juil. 2002 23:49:28

Version:

$Revision: 1.12 $ $Date: 2003/07/28 22:21:26 $

Author:

David Garnier

Field Summary

static int	DIMENSION2
static int	DIMENSION3
protected boolean	endianess
protected org.wkb4j.engine.WKBFactory	factory
protected java.io.DataInputStream	inputStream
protected org.wkb4j.engine.ResetableByteArrayInputStream	internalBuffer
protected static org.apache.log4j.Logger	log
protected java.lang.String[]	words

Fields inherited from interface org.wkb4j.engine.WKBGeometryTypes

linearRing, wkbGeometryCollection, wkbLineString, wkbMultiLineString, wkbMultiPoint, wkbMultiPolygon, wkbPoint, wkbPolygon

Constructor Summary

WKBParser(org.wkb4j.engine.WKBFactory _factory)
Constructor for WKBParser.

WKBParser(org.wkb4j.engine.WKBFactory _factory, java.lang.String[] _words, boolean _endianess)
Constructor for WKBParser.

Method Summary

protected void	decodeData(java.lang.String[] words, int[] values) Read the raw WKB data from the DataInputStream and generate the beginUnit/endUnit calls and the calls to the top-level geometries (MultiLineString, LineString, Polygon, MultiPolygon, GeometryCollection, Point) All the readGeometry method can throw IOException if something goes wrong.
private java.io.DataInputStream	getInputStream() Returns the DataInputStream used to transform bytes into native types (int and double in our case).
private org.wkb4j.engine.ResetableByteArrayInputStream	getInternalBuffer() Returns the ResetableByteArrayInputStream
void	parseData(byte[] buffer, byte[] sridBuffer) Load the raw bytes in the WKB format representing one record of the DB and generates the events.
void	parseData(byte[] buffer, byte[][] datas) Load the raw bytes in the WKB format and generates the events.
void	parseData(byte[] buffer, int srid) Load the raw bytes in the WKB format and generates the events.
protected int	parseInt(byte[] intBuffer, boolean endianess)
protected boolean	parseType(int geotype, int dimension) Read the given and generates the corresponding events.
protected void	readGeometryCollection() Reads a GeometryCollection.
protected void	readLinearRing(int dimension) Method readLinearRing.
protected void	readLineString(int dimension) Reads a LineString.
protected void	readMultiLineString() Reads a MultiLineString.
protected void	readMultiPoint() Reads a MultiPoint.
protected void	readMultiPolygon(int dimension) Reads a MultiPolygon.
protected void	readPoint(int dimension) Reads a Point.
protected void	readPoints(int pointCount, int dimension) Reads a number of Points.
protected void	readPolygon(int dimension) Reads a Polygon.
private void	setInternalBuffer(org.wkb4j.engine.ResetableByteArrayInputStream internalBuffer) Sets the ResetableByteArrayInputStream

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

log

protected static org.apache.log4j.Logger log

factory

protected org.wkb4j.engine.WKBFactory factory

DIMENSION2

public static final int DIMENSION2

See Also:

Constant Field Values

DIMENSION3

public static final int DIMENSION3

See Also:

Constant Field Values

internalBuffer

protected org.wkb4j.engine.ResetableByteArrayInputStream internalBuffer

inputStream

protected java.io.DataInputStream inputStream

words

protected java.lang.String[] words

endianess

protected final boolean endianess

Constructor Detail

WKBParser

public WKBParser(org.wkb4j.engine.WKBFactory _factory)

Constructor for WKBParser.

Parameters:

_factory - that will receive the events.

WKBParser

public WKBParser(org.wkb4j.engine.WKBFactory _factory,
                 java.lang.String[] _words,
                 boolean _endianess)

Constructor for WKBParser.

Parameters:

_factory - that will receive the events.

Method Detail

parseData

public void parseData(byte[] buffer,
                      byte[] sridBuffer)
               throws java.io.IOException

Load the raw bytes in the WKB format representing one record of the DB and generates the events. The sridBuffer should contain an array of bytes holding the SRID of the current geometry. If sridBuffer is null or longer than 4 bytes, the SRID of the current geometry is set to -1

Parameters:

buffer - array of bytes holding the data in the WKB format

sridBuffer - .

java.io.IOException

parseInt

protected int parseInt(byte[] intBuffer,
                       boolean endianess)
                throws java.io.IOException

java.io.IOException

parseData

public void parseData(byte[] buffer,
                      byte[][] datas)
               throws java.io.IOException

Load the raw bytes in the WKB format and generates the events.

Parameters:

buffer - array of bytes holding the data in the WKB format

java.io.IOException

parseData

public void parseData(byte[] buffer,
                      int srid)
               throws java.io.IOException

Load the raw bytes in the WKB format and generates the events.

Parameters:

buffer - array of bytes holding the data in the WKB format

srid - The SRID of the current geometry.

java.io.IOException

getInternalBuffer

private org.wkb4j.engine.ResetableByteArrayInputStream getInternalBuffer()

Returns the ResetableByteArrayInputStream

Returns:

ResetableByteArrayInputStream

setInternalBuffer

private void setInternalBuffer(org.wkb4j.engine.ResetableByteArrayInputStream internalBuffer)

Sets the ResetableByteArrayInputStream

Parameters:

internalBuffer - The ResetableByteArrayInputStream to set

getInputStream

private java.io.DataInputStream getInputStream()

Returns the DataInputStream used to transform bytes into native types (int and double in our case).

Returns:

DataInputStream

decodeData

protected void decodeData(java.lang.String[] words,
                          int[] values)

Read the raw WKB data from the DataInputStream and generate the beginUnit/endUnit calls and the calls to the top-level geometries (MultiLineString, LineString, Polygon, MultiPolygon, GeometryCollection, Point)
All the readGeometry method can throw IOException if something goes wrong.

parseType

protected boolean parseType(int geotype,
                            int dimension)
                     throws java.io.IOException

Read the given and generates the corresponding events. Do not call beginUnit(); nor endUnit():

Parameters:

geotype - type of the next Geometry.

dimension - dimension of the points contained in the next geometry.

Throws:

java.io.IOException

readMultiLineString

protected void readMultiLineString()
                            throws java.io.IOException

Reads a MultiLineString.

Throws:

java.io.IOException

readLineString

protected void readLineString(int dimension)
                       throws java.io.IOException

Reads a LineString.

Parameters:

dimension - dimension of the points contained in this geometry.

Throws:

java.io.IOException

readPoints

protected void readPoints(int pointCount,
                          int dimension)
                   throws java.io.IOException

Reads a number of Points.

Parameters:

pointCount -

dimension - unused parameter

Throws:

java.io.IOException

readMultiPolygon

protected void readMultiPolygon(int dimension)
                         throws java.io.IOException

Reads a MultiPolygon.

Parameters:

dimension - dimension of the points contained in this geometry.

Throws:

java.io.IOException

readPolygon

protected void readPolygon(int dimension)
                    throws java.io.IOException

Reads a Polygon.

Parameters:

dimension - dimension of the points contained in this geometry.

Throws:

java.io.IOException

readLinearRing

protected void readLinearRing(int dimension)
                       throws java.io.IOException

Method readLinearRing.

Parameters:

dimension - dimension of the points contained in this geometry.

Throws:

java.io.IOException

readMultiPoint

protected void readMultiPoint()
                       throws java.io.IOException

Reads a MultiPoint.

Throws:

java.io.IOException

readGeometryCollection

protected void readGeometryCollection()
                               throws java.io.IOException

Reads a GeometryCollection.

Throws:

java.io.IOException

readPoint

protected void readPoint(int dimension)
                  throws java.io.IOException

Reads a Point.

Parameters:

dimension - dimension of the points contained in this geometry.

Throws:

java.io.IOException