org.tinfour.gis.shapefile

Class DbfField

java.lang.Object

org.tinfour.gis.shapefile.DbfField

Direct Known Subclasses:

DbfFieldDate, DbfFieldDouble, DbfFieldInt

public class DbfField
extends Object

Provides definitions and access methods for a DBF field.

A number of features are not yet supported. Only the data types C (character), N (numeric) and F (floating-point) are supported. Only iso-8859-1 character sets are supported.

Field Summary

Fields

Modifier and Type	Field and Description
protected StringBuilder	builder
protected int	dataAddress
protected int	fieldDecimalCount
protected int	fieldLength
protected char	fieldType
protected boolean	isIntegral
protected String	name
protected boolean	numeric
protected int	offset

Method Summary

Modifier and Type	Method and Description
Object	getApplicationData() Gets the data for the field as an Object of the appropriate class.
double	getDouble() Gets the double value stored in the field during the most recent read operation, if any
int	getFieldDecimalCount() For numeric fields, indicates the number of decimal digits.
int	getFieldLength() Indicates the overall length of the data field
char	getFieldType() Indicates the type of the data field as defined in the DBF spec.
int	getInteger() Gets the integer value of the field, if it is of an integral type, otherwise returns a zero.
boolean	getLogicalValue() Gets a logical value.
String	getName() Gets the name of the data field
String	getString() Gets the string value stored in the field during the most recent read operation.
List<String>	getUniqueValues(DbfFileReader dbf) Gets the unique values for this field as a list of strings.
boolean	isIntegral() Indicates whether the field supports integral data value type.
boolean	isNull() Indicates whether the field contains a null value.
boolean	isNumeric() Indicates if the field defines a numeric value
String	toString()
boolean	usesEngineeringNotation() Indicates whether the value in the field was encoded using engineering notation (e.g.

Methods inherited from class java.lang.Object

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

Field Detail

name

protected final String name

fieldType

protected final char fieldType

dataAddress

protected final int dataAddress

fieldLength

protected final int fieldLength

fieldDecimalCount

protected final int fieldDecimalCount

offset

protected final int offset

builder

protected final StringBuilder builder

numeric

protected final boolean numeric

isIntegral

protected final boolean isIntegral

Method Detail

isIntegral

public boolean isIntegral()

Indicates whether the field supports integral data value type.

Returns:

true if the field can return an integer; otherwise, false

getInteger

public int getInteger()

Gets the integer value of the field, if it is of an integral type, otherwise returns a zero.

Returns:

a valid integral value, or a zero if undefined.

getDouble

public double getDouble()

Gets the double value stored in the field during the most recent read operation, if any

Returns:

a valid double or a NaN if this is not a numeric field

getString

public String getString()

Gets the string value stored in the field during the most recent read operation.

Returns:

a valid string, potentially empty

getName

public String getName()

Gets the name of the data field

Returns:

a valid string

getFieldType

public char getFieldType()

Indicates the type of the data field as defined in the DBF spec.

Returns:

a single character as defined in the DBF spec.

getFieldLength

public int getFieldLength()

Indicates the overall length of the data field

Returns:

the fieldLength

getFieldDecimalCount

public int getFieldDecimalCount()

For numeric fields, indicates the number of decimal digits.

Returns:

the fieldDecimalCount

isNumeric

public boolean isNumeric()

Indicates if the field defines a numeric value

Returns:

the numeric

getLogicalValue

public boolean getLogicalValue()

Gets a logical value.

Returns:

true if the field contains a logical value of TRUE; otherwise false.

toString

public String toString()

Overrides:

toString in class Object

getApplicationData

public Object getApplicationData()

Gets the data for the field as an Object of the appropriate class. For the DbdField base class, the return value is a string. For others, the return type may vary.

Returns:

an object, potentially null if the record has not been read.

usesEngineeringNotation

public boolean usesEngineeringNotation()

Indicates whether the value in the field was encoded using engineering notation (e.g. scientific notation). The return value will be false for all field types except floating-point types.

Returns:

true if engineering notation was used; otherwise false.

getUniqueValues

public List<String> getUniqueValues(DbfFileReader dbf)
                             throws IOException

Gets the unique values for this field as a list of strings.

Parameters:

dbf - the DBF with which this field is associated

Returns:

if successful, a valid list of unique values

Throws:

IOException - in the event of an unrecoverable IO condition.

isNull

public boolean isNull()

Indicates whether the field contains a null value. Because the interpretation of null fields is not well defined by the DBF file specification, this method should be used with care.

Returns:

true if the field is empty, otherwise false.