com.davisor.data
Class VoidValue

java.lang.Object
  com.davisor.data.VoidData
      com.davisor.data.VoidValue

All Implemented Interfaces:

java.lang.Comparable, Data, DataValue, com.davisor.core.Dupable, java.io.Serializable, SerializableData

Direct Known Subclasses:

GenericValue

public class VoidValue

extends VoidData

implements DataValue

VoidValue represents an undefined value. In particular, when compared against other defined values with min(com.davisor.data.DataValue) and max(com.davisor.data.DataValue) values, the other value is always returned.

Since:

JDK1.1

See Also:

Type, VoidType, Serialized Form

Field Summary

Fields inherited from class com.davisor.data.VoidData

M_type

Constructor Summary

	VoidValue() Default constructor.
protected	VoidValue(Type type) Create a new data object.
	VoidValue(VoidValue data, boolean deep) Deep or shallow copy constructor.

Method Summary

DataValue	abs() Returns absolute data value of current value.
DataValue	add(DataValue value) Adds data values.
DataValue	ceil(DataValue precision) Quantizes the current value up to an even value within given precision.
int	compareTo(java.lang.Object o) Compares this void value to other values.
double	deinterpolate(DataValue min, DataValue max) De-interpolates the current data value to a scalar value, in respect, with the given data value range.
DataValue	div(DataValue value) Divides the current value with given value.
com.davisor.core.Dupable	dup() Makes a deep copy of this object.
DataValue	floor(DataValue precision) Quantizes the current value down to an even value within given precision.
java.lang.String	getFormat() Gets the type specification optimal for this particular value.
DataValue	interpolate(double value, DataValue max) Interpolates the given scalar value to data value, in respect, with the range defined by this value and the given maximum value.
boolean	isNull() Tests if this data object value is undetermined.
DataValue	max(DataValue value) Finds the larger of two data values.
DataValue	min(DataValue value) Finds the smaller of two data values.
DataValue	mul(DataValue value) Multiplies the current value with given value.
DataValue	negate() Returns the negation of current value.
void	setValue(java.lang.String stringValue, java.text.ParsePosition status) Sets data value from a string value.
DataValue	sub(DataValue value) Subtracts a data value.
void	toStatement(java.sql.PreparedStatement statement, int parameter) Converts the data to a prepared statement input parameter.
java.lang.String	toXML() Gets the XML string representation of this value.
DataValue	unit(DataValue targetValue, double maxSteps) Gets the largest suitable unit step to represent a value change between this value and the given target value.

Methods inherited from class com.davisor.data.VoidData

equals, getDataValue, getType, hashCode, setType, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.davisor.data.DataValue

toString

Methods inherited from interface com.davisor.data.Data

getType

Constructor Detail

VoidValue

public VoidValue()

Default constructor.

VoidValue

public VoidValue(VoidValue data,
                 boolean deep)

Deep or shallow copy constructor. If it is shallow, then the new object shares an underlying type with the original object. If it is deep, then the type is dupped.

Parameters:

data - source data (may be null)

deep - determines if the copying is deep or shallow

See Also:

VoidData.getType(), Type.dup()

VoidValue

protected VoidValue(Type type)

Create a new data object.

Parameters:

type - The type of data.

Method Detail

compareTo

public int compareTo(java.lang.Object o)

Compares this void value to other values. A void value is always equal to null values and instances of VoidValue class, and smaller than anything else.

Specified by:

compareTo in interface java.lang.Comparable

See Also:

max(com.davisor.data.DataValue), min(com.davisor.data.DataValue), Data.getType(), Compare.compareTo(Object,Object)

isNull

public boolean isNull()

Tests if this data object value is undetermined.

Specified by:

isNull in interface SerializableData

Returns:

always true

See Also:

Type.isNull(com.davisor.data.SerializableData)

abs

public DataValue abs()
              throws InvalidDataException

Returns absolute data value of current value. Taking void value absolute value returns a duplicate of this object. This behaviour is expected to be overridden by most subclasses.

Specified by:

abs in interface DataValue

Returns:

a new data object, sharing the current type of this object

Throws:

InvalidDataException - if absolute value can not be computed

add

public DataValue add(DataValue value)
              throws InvalidDataException

Adds data values. Adding a void data value to any other data value returns a duplicate of the other value. If the other value is null, a duplicate of this object is returned. This behaviour is expected to be overridden by most subclasses.

Specified by:

add in interface DataValue

Parameters:

value - a data value to be added to this data value

Returns:

a new data object

Throws:

InvalidDataException - if the data values can not be added

ceil

public DataValue ceil(DataValue precision)
               throws InvalidDataException

Quantizes the current value up to an even value within given precision. Quantizing a void data value returns a duplicate of this object. This behaviour is expected to be overridden by most subclasses.

Specified by:

ceil in interface DataValue

Parameters:

precision - the precision within quantization occurs (ignored)

Returns:

a new data object, sharing the current type of this object

Throws:

InvalidDataException - if precision was of unacceptable type

See Also:

floor(com.davisor.data.DataValue)

deinterpolate

public double deinterpolate(DataValue min,
                            DataValue max)
                     throws InvalidDataException

De-interpolates the current data value to a scalar value, in respect, with the given data value range. De-interpolating a void data value against any value range returns a NaN number value. This behaviour is expected to be overridden by most subclasses.

Specified by:

deinterpolate in interface DataValue

Parameters:

min - a data value representing a range's lower limit (ignored)

max - a data value representing a range's higher limit (ignored)

Returns:

de-interpolated scalar value (always NaN)

Throws:

InvalidDataException - if the de-interpolation fails for some other reason

See Also:

DataValue.interpolate(double, com.davisor.data.DataValue), DeinterpolationException, TupleData.deinterpolate(com.davisor.data.DataValue, com.davisor.data.DataValue)

div

public DataValue div(DataValue value)
              throws InvalidDataException

Divides the current value with given value. Division returns always zero value of the divider type. This behaviour is expected to be overridden by most subclasses.

Specified by:

div in interface DataValue

Parameters:

value - the divider

Returns:

a new data object.

Throws:

InvalidDataException - if current divider is null or zero value.

floor

public DataValue floor(DataValue precision)
                throws InvalidDataException

Quantizes the current value down to an even value within given precision. Quantizing a void data value returns a duplicate of this object. This behaviour is expected to be overridden by most subclasses.

Specified by:

floor in interface DataValue

Parameters:

precision - the precision within quantization occurs

Returns:

a new data object, sharing the current type of this object

Throws:

InvalidDataException - if precision was of unacceptable type

See Also:

ceil(com.davisor.data.DataValue)

getFormat

public java.lang.String getFormat()

Gets the type specification optimal for this particular value. The specification returned may differ from the current type specification. If so, setting the current type specification equal with the value returned by this method will ensure optimal value formatting and parsing for values of the same magnitude as this value.

The void data optimal specificaton string is always the current specification string for the current type.

Specified by:

getFormat in interface DataValue

See Also:

Data.getType(), FormatType.getFormat(), FormatType.setFormat(java.util.Locale, java.lang.String)

interpolate

public DataValue interpolate(double value,
                             DataValue max)
                      throws InvalidDataException

Interpolates the given scalar value to data value, in respect, with the range defined by this value and the given maximum value. The result will always be a duplicate of this object. This behaviour is expected to be overridden by most subclasses.

Specified by:

interpolate in interface DataValue

Parameters:

value - the scalar value to be interpolated

max - a data value representing a range's higher limit

Returns:

a new data object containing the result

Throws:

InvalidDataException - if the interpolation fails

See Also:

DataValue.deinterpolate(com.davisor.data.DataValue, com.davisor.data.DataValue)

max

public DataValue max(DataValue value)
              throws InvalidDataException

Finds the larger of two data values. If the given value is null, a reference to this instance is returned, otherwise value is returned.

Please note, that this behaviour is not typical, as the same void value may be both smaller and greater than an other value, depending which of the min or max methods is called.

Specified by:

max in interface DataValue

Parameters:

value - a data value to be compared with this data value

Returns:

the largest of the compared data values

Throws:

InvalidDataException - if the data value cannot be compared

See Also:

min(com.davisor.data.DataValue)

min

public DataValue min(DataValue value)
              throws InvalidDataException

Finds the smaller of two data values. If the given value is null, a reference to this instance is returned, otherwise value is returned.

Please note, that this behaviour is not typical, as the same void value may be both smaller and greater than an other value, depending which of the min or max methods is called.

Specified by:

min in interface DataValue

Parameters:

value - a data value to be compared with this data value

Returns:

the largest of the compared data values

Throws:

InvalidDataException - if the data value cannot be compared

See Also:

max(com.davisor.data.DataValue)

mul

public DataValue mul(DataValue value)
              throws InvalidDataException

Multiplies the current value with given value. Multiplication returns always zero value of the multiplier type. This behaviour is expected to be overridden by most subclasses.

Specified by:

mul in interface DataValue

Parameters:

value - the multiplier

Returns:

a new data object.

Throws:

InvalidDataException - if current multiplier is null.

negate

public DataValue negate()
                 throws InvalidDataException

Returns the negation of current value. Taking a negation of a void value returns a duplicate of this object. This behaviour is expected to be overridden by most subclasses.

Specified by:

negate in interface DataValue

Returns:

a new data object, sharing the current type of this object

Throws:

InvalidDataException - if absolute value can not be computed

setValue

public void setValue(java.lang.String stringValue,
                     java.text.ParsePosition status)
              throws InvalidDataException

Sets data value from a string value.

Void values have no value, so given string value is just ignored.

Specified by:

setValue in interface DataValue

Parameters:

stringValue - string value to be parsed (ignored)

status - parse status (ignored)

Throws:

InvalidDataException - if string value could not be parser

See Also:

CountType.countValue(String,ParsePosition)

sub

public DataValue sub(DataValue value)
              throws InvalidDataException

Subtracts a data value. Substracting a value from a void value returns a negation of the other value. This behaviour is expected to be overridden by most subclasses.

Specified by:

sub in interface DataValue

Parameters:

value - a data value to be subtracted from this data value

Returns:

a new data object, sharing the current type of this object

Throws:

InvalidDataException - if the value cannot be substracted.

toStatement

public void toStatement(java.sql.PreparedStatement statement,
                        int parameter)
                 throws java.sql.SQLException

Converts the data to a prepared statement input parameter. The parameter value is always set to null.

Specified by:

toStatement in interface DataValue

Parameters:

statement - statement to be updated

parameter - index of the statement parameter to be updated

Throws:

java.sql.SQLException - if a SQL error occurs.

toXML

public java.lang.String toXML()

Gets the XML string representation of this value.

This default implementation returns always <null/> tag.

Specified by:

toXML in interface DataValue

Returns:

complete string representing the data.

See Also:

VoidData.toString(), XMLUnicodeEncoder.encode(java.lang.String, boolean)

unit

public DataValue unit(DataValue targetValue,
                      double maxSteps)
               throws InvalidDataException

Gets the largest suitable unit step to represent a value change between this value and the given target value. Taking an unit step from a void data value returns a duplicate of this object. This behaviour is expected to be overridden by most subclasses.

Specified by:

unit in interface DataValue

Parameters:

targetValue - target value to be reached (ignored)

maxSteps - maximum number of steps (zero leaves the choise open)

Returns:

a new data object, sharing the current type of this object

Throws:

InvalidDataException - if target value is unsuitable

dup

public com.davisor.core.Dupable dup()

Makes a deep copy of this object.

Specified by:

dup in interface com.davisor.core.Dupable