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

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

public class DBaseFile

extends ShapeUtils

Class representing a DBase File. Title : Earth Copyright : Copyright (c) 2001 Organisation : IGD FhG

Version:

: 1.0

Author:

: Werner Beutel

Field Summary

static int	DEFAULT_RECORD_BUFFER_SIZE_DB A default DBase record size.
protected int[]	fieldLength A field that holds the length of the DBase fields, in bytes.
protected String[]	fieldName A field that holds the names of the DBase fields, as a string.
protected char[]	fieldType A field that holds the types of the DBase fields, as a char.
protected long	fileLength Holds the length of the DBase file, in bytes.
protected byte[]	header The buffer that holds header of the DBase file.
protected int	headerLength Holds the length of the DBase file header.
protected boolean	io A flag for the IO mode true=read/write false=read.
protected RandomAccessFile	raf The read/write class for shape DBase files.
protected byte[]	recBuf A buffer for the current DBase record's data.
protected int	recordLength Holds the record length of the DBase file, as an int.
protected int	recordNumbers Holds the numbers of the records, in bytes.
protected int	rows Holds the numbers of the row of the DBase file, as an int.

Fields inherited from class de.fhg.igd.earth.model.input.shapefile.ShapeUtils

SHAPE_FILE_HEADER_LENGTH, SHAPE_FILE_HEADER_LENGTH_DB, SHAPE_FILE_RECORD_HEADER_LENGTH, SHAPE_TYPE_ARC, SHAPE_TYPE_MULTIPOINT, SHAPE_TYPE_NULL, SHAPE_TYPE_POINT, SHAPE_TYPE_POLYGON, SHAPE_TYPE_POLYLINE

Constructor Summary

DBaseFile(String name)
Construct a DBaseFile from a file name.

Method Summary

void	addRecord(DBaseFile dbf) Adds a record to the end of this file.
void	close() Closes the DBase file and disposes of resources.
String	getFieldData(int index) Returns the field data of the table at the current position
String	getFieldName(int index) Returns the field name of the DBase table
char	getFieldType(int index) Returns the field type of the table
int	getNextRecord() Reads the next record from the DBase file Each successive call gets the next record.
protected void	initHeader() Reads or initialises the header of a DBase file.
int	numRows() Returns the number of rows of the DBase table
protected void	readHeader() Reads and parses the header of the file.
void	writeHeader(DBaseFile dbf) Writes a header into an empty DBase file A prototype header of another DBase file is needed

Methods inherited from class de.fhg.igd.earth.model.input.shapefile.ShapeUtils

readBEInt, readBox, readLEDouble, readLEInt, readLEInt, readLELong, readPoint, writeBEInt, writeBox, writeLEDouble, writeLEInt, writeLELong, writePoint

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_RECORD_BUFFER_SIZE_DB

public static final int DEFAULT_RECORD_BUFFER_SIZE_DB

A default DBase record size. Automatically increased on demand.

See Also:

Constant Field Values

raf

protected RandomAccessFile raf

The read/write class for shape DBase files.

header

protected byte[] header

The buffer that holds header of the DBase file.

headerLength

protected int headerLength

Holds the length of the DBase file header.

fileLength

protected long fileLength

Holds the length of the DBase file, in bytes.

recordNumbers

protected int recordNumbers

Holds the numbers of the records, in bytes.

rows

protected int rows

Holds the numbers of the row of the DBase file, as an int.

recordLength

protected int recordLength

Holds the record length of the DBase file, as an int.

recBuf

protected byte[] recBuf

A buffer for the current DBase record's data.

io

protected boolean io

A flag for the IO mode true=read/write false=read.

fieldName

protected String[] fieldName

A field that holds the names of the DBase fields, as a string.

fieldLength

protected int[] fieldLength

A field that holds the length of the DBase fields, in bytes.

fieldType

protected char[] fieldType

A field that holds the types of the DBase fields, as a char.

Constructor Detail

DBaseFile

public DBaseFile(String name)
          throws IOException

Construct a DBaseFile from a file name.

Throws:

IOException - if something goes wrong opening or reading the file.

Method Detail

initHeader

protected void initHeader()
                   throws IOException

Reads or initialises the header of a DBase file. If the file is not empty, the header is read.

After this function runs, the file pointer is set to the first byte of the first record in the file.

Throws:

IOException - if something goes wrong reading or writing the DBase file

writeHeader

public void writeHeader(DBaseFile dbf)
                 throws IOException

Writes a header into an empty DBase file A prototype header of another DBase file is needed

Throws:

IOException - if something goes wrong reading the file

readHeader

protected void readHeader()
                   throws IOException

Reads and parses the header of the file. Values from the header are stored in the fields of this class.

Throws:

IOException - if something goes wrong reading the file

numRows

public int numRows()

Returns the number of rows of the DBase table

getFieldName

public String getFieldName(int index)

Returns the field name of the DBase table

Throws:

IOException - if something goes wrong reading the file

getFieldData

public String getFieldData(int index)

Returns the field data of the table at the current position

Throws:

IOException - if something goes wrong reading the file

getFieldType

public char getFieldType(int index)

Returns the field type of the table

Throws:

IOException - if something goes wrong reading the file

getNextRecord

public int getNextRecord()
                  throws IOException

Reads the next record from the DBase file Each successive call gets the next record. There is no way to go back a record. When there are no more records, null is returned.

Returns:

a record length, or 0 if there are no more records

Throws:

IOException - if something goes wrong reading the file

addRecord

public void addRecord(DBaseFile dbf)
               throws IOException

Adds a record to the end of this file. The record is written to the file at the end of the last record.

Throws:

IOException - if something goes wrong writing to the file

close

public void close()
           throws IOException

Closes the DBase file and disposes of resources.

Throws:

IOException - if something goes wrong closing the file