org.geotools.data.shapefile.shp

Class IndexFile

Object

IndexFile

All Implemented Interfaces:

FileReader

public class IndexFile
extends Object
implements FileReader

IndexFile parser for .shx files.
For now, the creation of index files is done in the ShapefileWriter. But this can be used to access the index.
For details on the index file, see
"ESRI(r) Shapefile - A Technical Description"
* 'An ESRI White Paper . May 1997'

Author:

Ian Schneider

Constructor Summary

Constructors

Constructor and Description
IndexFile(ShpFiles shpFiles, boolean useMemoryMappedBuffer) Load the index file from the given channel.

Method Summary

Modifier and Type	Method and Description
void	close()
protected void	finalize()
int	getContentLength(int index) Get the content length of the given record in bytes, not 16 bit words.
ShapefileHeader	getHeader() Get the header of this index file.
int	getOffset(int index) Get the offset of the record (in 16-bit words).
int	getOffsetInBytes(int index) Get the offset of the record (in real bytes, not 16-bit words).
int	getRecordCount() Get the number of records in this index.
String	id() An id for the reader.

Methods inherited from class Object

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

Constructor Detail

IndexFile

public IndexFile(ShpFiles shpFiles,
                 boolean useMemoryMappedBuffer)
          throws IOException

Load the index file from the given channel.

Parameters:

shpFiles - The channel to read from.

Throws:

IOException - If an error occurs.

Method Detail

getHeader

public ShapefileHeader getHeader()

Get the header of this index file.

Returns:

The header of the index file.

close

public void close()
           throws IOException

Throws:

IOException

finalize

protected void finalize()
                 throws Throwable

Overrides:

finalize in class Object

Throws:

Throwable

See Also:

Object.finalize()

getRecordCount

public int getRecordCount()

Get the number of records in this index.

Returns:

The number of records.

getOffset

public int getOffset(int index)
              throws IOException

Get the offset of the record (in 16-bit words).

Parameters:

index - The index, from 0 to getRecordCount - 1

Returns:

The offset in 16-bit words.

Throws:

IOException

getOffsetInBytes

public int getOffsetInBytes(int index)
                     throws IOException

Get the offset of the record (in real bytes, not 16-bit words).

Parameters:

index - The index, from 0 to getRecordCount - 1

Returns:

The offset in bytes.

Throws:

IOException

getContentLength

public int getContentLength(int index)
                     throws IOException

Get the content length of the given record in bytes, not 16 bit words.

Parameters:

index - The index, from 0 to getRecordCount - 1

Returns:

The lengh in bytes of the record.

Throws:

IOException

id

public String id()

Description copied from interface: FileReader

An id for the reader. This is only used for debugging.

Specified by:

id in interface FileReader

Returns:

id for the reader.