prajna.data.field

Class MeasureFieldDesc

java.lang.Object

prajna.data.field.FieldDesc<Measure>

prajna.data.field.MeasureFieldDesc

All Implemented Interfaces:

java.io.Serializable, Xmlizable

public class MeasureFieldDesc
extends FieldDesc<Measure>

Field description for fields representing measurements. This class attempts to identify the measurement type, but expects the data to provide information about the type of measurement when feasible.

Author:

Edward Swing

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
MeasureFieldDesc() Default constructor with no arguments, useful for cases where the descriptor is configured from XML elements.
MeasureFieldDesc(java.lang.String fieldName, java.lang.Class<? extends Unit> unitCls) Constructor taking a field name and unit class.
MeasureFieldDesc(java.lang.String fieldName, Unit defaultUnit) Constructor taking a field name and default unit of measure.

Method Summary

Methods

Modifier and Type	Method and Description
Unit	getDefaultUnit() Get the default unit for this measure field descriptor
DataType	getFieldType() Get the field type for this field description
java.lang.Class<? extends Unit>	getUnitClass() Get the class used for the units specified by this measure type.
boolean	isValid(Measure value) Return whether a field value is valid.
Measure	parse(java.lang.String stringVal) Parse the value into the format for this field description.
Measure	parseValueIntoRecord(DataRecord rec, java.lang.String value) Parse the string value, and store it in a measure field in the specified data record.
protected void	setValues(org.w3c.dom.NodeList valueList) Set the values for this Measure field description.
void	storeDefaultIntoRecord(DataRecord rec) Store the default value into the data record provided.
org.w3c.dom.Element	toXml(org.w3c.dom.Document doc) Convert this field description to an XML Element.

Methods inherited from class prajna.data.field.FieldDesc

addSourceField, applyTransform, getDefaultValue, getFieldName, getLookupIndexField, getLookupTable, getLookupValueField, getSourceFields, getTransform, isMultiValue, loadFromXml, setDefaultValue, setFieldName, setMultiValue

Methods inherited from class java.lang.Object

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

Constructor Detail

MeasureFieldDesc

public MeasureFieldDesc()

Default constructor with no arguments, useful for cases where the descriptor is configured from XML elements.

MeasureFieldDesc

public MeasureFieldDesc(java.lang.String fieldName,
                java.lang.Class<? extends Unit> unitCls)

Constructor taking a field name and unit class.

Parameters:

fieldName - the field name for this descriptor

unitCls - the unit class for this measure spec

MeasureFieldDesc

public MeasureFieldDesc(java.lang.String fieldName,
                Unit defaultUnit)

Constructor taking a field name and default unit of measure.

Parameters:

fieldName - the field name for this descriptor

defaultUnit - the default unit for this measure spec

Method Detail

getDefaultUnit

public Unit getDefaultUnit()

Get the default unit for this measure field descriptor

Returns:

the default unit

getFieldType

public DataType getFieldType()

Get the field type for this field description

Specified by:

getFieldType in class FieldDesc<Measure>

Returns:

FieldType.MEASURE

getUnitClass

public java.lang.Class<? extends Unit> getUnitClass()

Get the class used for the units specified by this measure type.

Returns:

the unit class

isValid

public boolean isValid(Measure value)

Return whether a field value is valid. This method checks if the unit class, and therefore measurement type, of the argument coincide with the measurement type of this field description.

Specified by:

isValid in class FieldDesc<Measure>

Parameters:

value - the field value

Returns:

true if the field is valid for this field description, false otherwise

parse

public Measure parse(java.lang.String stringVal)
              throws java.text.ParseException

Parse the value into the format for this field description. This method breaks the string into a numeric component and a unit string. The unit string, if present, is checked against compatible units of measure. This allows values in multiple units which measure the same property (length, mass, etc) to be specified in the same field. If there is no unit string, the default unit is used. The measurement is constructed from the unit identified and the numeric component, which should parse as a floating point value.

Specified by:

parse in class FieldDesc<Measure>

Parameters:

stringVal - the value to parse

Returns:

the parsed measurement

Throws:

java.text.ParseException - if the string cannot be parsed as an measurement

parseValueIntoRecord

public Measure parseValueIntoRecord(DataRecord rec,
                           java.lang.String value)
                             throws java.text.ParseException

Parse the string value, and store it in a measure field in the specified data record. The DataRecord.setMeasureField method will be invoked with a measure constructed from the parse() method.

Specified by:

parseValueIntoRecord in class FieldDesc<Measure>

Parameters:

rec - the DataRecord to parse the value into

value - the String value to be parsed

Returns:

the measure value added

Throws:

java.text.ParseException - if the value cannot be parsed properly

setValues

protected void setValues(org.w3c.dom.NodeList valueList)

Set the values for this Measure field description. This method looks for a child element with a tag name of type to specify the unit type. This value should be a measurement quantity type, such as Length or Mass. The method also looks for a unit element, which specifies the default unit. If the default unit is not specified, the base unit is used for the default unit.

Specified by:

setValues in class FieldDesc<Measure>

Parameters:

valueList - list of value nodes. These are child nodes of the < values element

storeDefaultIntoRecord

public void storeDefaultIntoRecord(DataRecord rec)

Store the default value into the data record provided. If the default value is null, no action is taken.

Specified by:

storeDefaultIntoRecord in class FieldDesc<Measure>

Parameters:

rec - the DataRecord to store the value into

toXml

public org.w3c.dom.Element toXml(org.w3c.dom.Document doc)

Convert this field description to an XML Element. This method creates a fieldDef element, sets the fieldName and fieldType, and creates a values child element. The values element contains the unit type and the default unit. If the default value is set, this method adds it as well.

Specified by:

toXml in interface Xmlizable

Specified by:

toXml in class FieldDesc<Measure>

Parameters:

doc - The document used to construct the element

Returns:

the element representing this field description