org.tinfour.gis.shapefile

Class ShapefileReader

java.lang.Object

org.tinfour.gis.shapefile.ShapefileReader

All Implemented Interfaces:

Closeable, AutoCloseable

public class ShapefileReader
extends Object
implements Closeable

Provides a partial implementation of a Shapefile reader intended to support testing of the Constrained Delaunay Triangulation feature of the Tinfour software library. The present version is based on the assumption that the Shapefile supplies constraints. More general applicastions are not currently supported. Only a few Shapefile types are supported.

Constructor Summary

Constructors

Constructor and Description
ShapefileReader(File file)

Method Summary

Modifier and Type	Method and Description
void	close() Close the associated file
File	getCoFile(String extension) Get a reference to the file that shares the same root name as the Shapefile but has an alternate extension.
DbfFileReader	getDbfFileReader() Get an DBF file reader for the current Shapefile
File	getFile() Get the file associated with the Shapefile.
long	getFilePosition() Provides the current position within the main Shapefile.
long	getFileSize() Gets the current size of the main Shapefile in bytes.
double	getMaxX() Gets the maximum value for the x coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.
double	getMaxY() Gets the maximum value for the y coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.
double	getMaxZ() Gets the maximum value for the z coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.
double	getMinX() Gets the minimum value for the x coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.
double	getMinY() Gets the minimum value for the y coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.
double	getMinZ() Gets the minimum value for the z coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.
ShapefileType	getShapefileType() Get the feature type of the Shapefile.
int	getTotalPartCount() Gets the total number of polyglines read from the Shapefile; or zero if the content of the Shapefile hasn't been read.
int	getTotalPointCount() Gets the total number of points read from the Shapefile; or zero if the content of the Shapefile hasn't been read.
boolean	hasNext() Checks to see if there are any more records remaining to be read
ShapefileRecord	readNextRecord(ShapefileRecord pRecord) Reads the next record in the Shapefile.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

ShapefileReader

public ShapefileReader(File file)
                throws IOException

Throws:

IOException

Method Detail

close

public void close()
           throws IOException

Close the associated file

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException - in the event of an unexpected I/O exception

getMinX

public double getMinX()

Gets the minimum value for the x coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.

Returns:

the minimum value for the x coordinates in the file

getMaxX

public double getMaxX()

Gets the maximum value for the x coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.

Returns:

the maximum value for the x coordinates in the file

getMinY

public double getMinY()

Gets the minimum value for the y coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.

Returns:

the minimum value for the y coordinates in the file

getMaxY

public double getMaxY()

Gets the maximum value for the y coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.

Returns:

the maximum value for the y coordinates in the file.

getMinZ

public double getMinZ()

Gets the minimum value for the z coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.

Returns:

the minimum value for the z coordinates in the file.

getMaxZ

public double getMaxZ()

Gets the maximum value for the z coordinates of the points in the Shapefile as specified in the Shapefile-standard file header.

Returns:

the maximum value for the z coordinates in the file.

readNextRecord

public ShapefileRecord readNextRecord(ShapefileRecord pRecord)
                               throws IOException

Reads the next record in the Shapefile. This method takes a reusable instance of the ShapefileRecord class. If a null is passed in, it creates a new instance. If a valid reference is supplied, the method returns the reference that was supplied.

Parameters:

pRecord - a reusable instance to store data, or a null if the method is to allocate a new instance.

Returns:

if successful, a valid instance of ShapefileRecord

Throws:

IOException - in the event of a file format error or unepected I/O condition

hasNext

public boolean hasNext()

Checks to see if there are any more records remaining to be read

Returns:

true if more records remain; otherwise false.

getTotalPointCount

public int getTotalPointCount()

Gets the total number of points read from the Shapefile; or zero if the content of the Shapefile hasn't been read.

Returns:

a positive integer.

getTotalPartCount

public int getTotalPartCount()

Gets the total number of polyglines read from the Shapefile; or zero if the content of the Shapefile hasn't been read.

Returns:

a positive integer.

getShapefileType

public ShapefileType getShapefileType()

Get the feature type of the Shapefile.

Returns:

a valid enumeration instance.

toString

public String toString()

Overrides:

toString in class Object

getCoFile

public File getCoFile(String extension)

Get a reference to the file that shares the same root name as the Shapefile but has an alternate extension. For example, this method could be used to get a reference to the DBF or PRJ file.

Capitalization does not matter under Windows, but does apply under Linux operating systems. Therefore, this method will try to find the matching file based on the following three rules:

1. Look for a file with an extension having the same capitalization as the main Shapefile
2. Look for a file having the extension as all lower case letters
3. Look for a file having the extension with all upper case letters

While there are other possible capitalization configurations, writing code to support them seems silly and is not implemented at this time.

Parameters:

extension - a string giving the target extension (do not include period)

Returns:

if found, a valid instance; otherwise, a null

getDbfFileReader

public DbfFileReader getDbfFileReader()
                               throws IOException

Get an DBF file reader for the current Shapefile

Returns:

if successful, a valid DbfFileReader instance.

Throws:

IOException - if the DBF file cannot be opened

getFile

public File getFile()

Get the file associated with the Shapefile.

Returns:

a valid instance

getFileSize

public long getFileSize()

Gets the current size of the main Shapefile in bytes.

Returns:

A long integer giving file size in bytes.

getFilePosition

public long getFilePosition()

Provides the current position within the main Shapefile.

Returns:

a long integer value giving offset in bytes from beginning of file.