de.fhg.igd.earth.model.input.shapefile
Class ShapeUtils

java.lang.Object
  de.fhg.igd.earth.model.input.shapefile.ShapeUtils

Direct Known Subclasses:

DBaseFile, ESRIPoly, ESRIRecord, ShapeFile

public class ShapeUtils

extends Object

Title : Earth Copyright : Copyright (c) 2001 Organisation : IGD FhG

Version:

: 1.0

Author:

: Werner Beutel

Field Summary

private static byte[]	leiBuffer A buffer for reading/writing little endian ints.
static int	SHAPE_FILE_HEADER_LENGTH The length of a shape file header in bytes.
static int	SHAPE_FILE_HEADER_LENGTH_DB
static int	SHAPE_FILE_RECORD_HEADER_LENGTH The length of a shape file record header in bytes.
static int	SHAPE_TYPE_ARC The indicator for an arc (polyline) shape type.
static int	SHAPE_TYPE_MULTIPOINT The indicator for a multipoint shape type.
static int	SHAPE_TYPE_NULL The indicator for a null shape type.
static int	SHAPE_TYPE_POINT The indicator for a point shape type.
static int	SHAPE_TYPE_POLYGON The indicator for a polygon shape type.
static int	SHAPE_TYPE_POLYLINE The indicator for a polyline (arc) shape type.

Constructor Summary

ShapeUtils()

Method Summary

static int	readBEInt(byte[] b, int off) Reads a big endian integer.
static ESRIBoundingBox	readBox(byte[] b, int off) Reads a bounding box record.
static double	readLEDouble(byte[] b, int off) Reads a little endian double.
static int	readLEInt(byte[] b, int off) Reads a little endian integer.
static int	readLEInt(RandomAccessFile in) Reads a little endian int from the current location of the given file.
static long	readLELong(byte[] b, int off) Reads a little endian 8 byte integer.
static ESRIPoint	readPoint(byte[] b, int off) Reads a point record.
static int	writeBEInt(byte[] b, int off, int val) Writes the given integer to the given buffer at the given location in big endian format.
static int	writeBox(byte[] b, int off, ESRIBoundingBox box) Writes the given bounding box to the given buffer at the given location.
static int	writeLEDouble(byte[] b, int off, double val) Writes the given double to the given buffer at the given location in little endian format.
static int	writeLEInt(byte[] b, int off, int val) Writes the given integer to the given buffer at the given location in little endian format.
static int	writeLELong(byte[] b, int off, long val) Writes the given long to the given buffer at the given location in little endian format.
static int	writePoint(byte[] b, int off, ESRIPoint point) Writes the given point to the given buffer at the given location.

Methods inherited from class java.lang.Object

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

Field Detail

SHAPE_FILE_HEADER_LENGTH

public static final int SHAPE_FILE_HEADER_LENGTH

The length of a shape file header in bytes. (100)

See Also:

Constant Field Values

SHAPE_FILE_HEADER_LENGTH_DB

public static final int SHAPE_FILE_HEADER_LENGTH_DB

See Also:

Constant Field Values

SHAPE_FILE_RECORD_HEADER_LENGTH

public static final int SHAPE_FILE_RECORD_HEADER_LENGTH

The length of a shape file record header in bytes. (8)

See Also:

Constant Field Values

SHAPE_TYPE_NULL

public static final int SHAPE_TYPE_NULL

The indicator for a null shape type. (0)

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Constant Field Values

SHAPE_TYPE_POINT

public static final int SHAPE_TYPE_POINT

The indicator for a point shape type. (1)

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Constant Field Values

SHAPE_TYPE_ARC

public static final int SHAPE_TYPE_ARC

The indicator for an arc (polyline) shape type. (3)

See Also:

Constant Field Values

SHAPE_TYPE_POLYLINE

public static final int SHAPE_TYPE_POLYLINE

The indicator for a polyline (arc) shape type. (3). NOTE: ESRI decided to rename the `arc' type as the `polyline' type as of their July 1998 Shapefile Technical Description paper. Maybe they should rename Arc/Info as Polyline/Info?...

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Constant Field Values

SHAPE_TYPE_POLYGON

public static final int SHAPE_TYPE_POLYGON

The indicator for a polygon shape type. (5)

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Constant Field Values

SHAPE_TYPE_MULTIPOINT

public static final int SHAPE_TYPE_MULTIPOINT

The indicator for a multipoint shape type. (8)

See Also:

Constant Field Values

leiBuffer

private static byte[] leiBuffer

A buffer for reading/writing little endian ints.

Constructor Detail

ShapeUtils

public ShapeUtils()

Method Detail

readBEInt

public static int readBEInt(byte[] b,
                            int off)

Reads a big endian integer.

Parameters:

b - the raw data buffer

off - the offset into the buffer where the int resides

Returns:

the int read from the buffer at the offset location

readLEInt

public static int readLEInt(byte[] b,
                            int off)

Reads a little endian integer.

Parameters:

b - the raw data buffer

off - the offset into the buffer where the int resides

Returns:

the int read from the buffer at the offset location

readLEInt

public static int readLEInt(RandomAccessFile in)
                     throws IOException

Reads a little endian int from the current location of the given file. Synchronized for thread-safe access to leiBuffer.

Parameters:

in - an input file

Returns:

the int read from the file

Throws:

IOException

readLELong

public static long readLELong(byte[] b,
                              int off)

Reads a little endian 8 byte integer.

Parameters:

b - the raw data buffer

off - the offset into the buffer where the long resides

Returns:

the long read from the buffer at the offset location

readLEDouble

public static double readLEDouble(byte[] b,
                                  int off)

Reads a little endian double.

Parameters:

b - the raw data buffer

off - the offset into the buffer where the double resides

Returns:

the double read from the buffer at the offset location

readPoint

public static ESRIPoint readPoint(byte[] b,
                                  int off)

Reads a point record. A point record is a double representing the x value and a double representing a y value.

Parameters:

b - the raw data buffer

off - the offset into the buffer where the int resides

Returns:

the point read from the buffer at the offset location

readBox

public static ESRIBoundingBox readBox(byte[] b,
                                      int off)

Reads a bounding box record. A bounding box is four double representing, in order, xmin, ymin, xmax, ymax.

Parameters:

b - the raw data buffer

off - the offset into the buffer where the int resides

Returns:

the point read from the buffer at the offset location

writeBEInt

public static int writeBEInt(byte[] b,
                             int off,
                             int val)

Writes the given integer to the given buffer at the given location in big endian format.

Parameters:

b - the data buffer

off - the offset into the buffer where writing should occur

val - the integer to write

Returns:

the number of bytes written

writeLEInt

public static int writeLEInt(byte[] b,
                             int off,
                             int val)

Writes the given integer to the given buffer at the given location in little endian format.

Parameters:

b - the data buffer

off - the offset into the buffer where writing should occur

val - the integer to write

Returns:

the number of bytes written

writeLELong

public static int writeLELong(byte[] b,
                              int off,
                              long val)

Writes the given long to the given buffer at the given location in little endian format.

Parameters:

b - the data buffer

off - the offset into the buffer where writing should occur

val - the long to write

Returns:

the number of bytes written

writeLEDouble

public static int writeLEDouble(byte[] b,
                                int off,
                                double val)

Writes the given double to the given buffer at the given location in little endian format.

Parameters:

b - the data buffer

off - the offset into the buffer where writing should occur

val - the double to write

Returns:

the number of bytes written

writePoint

public static int writePoint(byte[] b,
                             int off,
                             ESRIPoint point)

Writes the given point to the given buffer at the given location. The point is written as a double representing x followed by a double representing y.

Parameters:

b - the data buffer

off - the offset into the buffer where writing should occur

Returns:

the number of bytes written

writeBox

public static int writeBox(byte[] b,
                           int off,
                           ESRIBoundingBox box)

Writes the given bounding box to the given buffer at the given location. The bounding box is written as four doubles representing, in order, xmin, ymin, xmax, ymax.

Parameters:

b - the data buffer

off - the offset into the buffer where writing should occur

Returns:

the number of bytes written