Package com.jgoodies.common.format

Class EmptyFormat

java.lang.Object

java.text.Format

com.jgoodies.common.format.EmptyFormat

All Implemented Interfaces:

Serializable, Cloneable

public class EmptyFormat
extends Format

Wraps a given Format and adds behavior to convert to/from the empty string. Therefore it holds an empty value (often null) that is mapped to/from the empty string. The #format result of the empty value is the empty string, and the #parse result of the empty string is the empty value. In all other cases the formatting and parsing is forwarded to the wrapped Format.

If you want to wrap a DateFormat or NumberFormat, you may use EmptyDateFormat or EmptyNumberFormat resp. Examples:

 new EmptyFormat(new WeightFormat());
 

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.text.Format

Format.Field

Field Summary

Fields

Modifier and Type	Field	Description
private final Format	delegate	Refers to the wrapped Format that is used to forward #format and #parseObject.
private final Object	emptyValue	Holds the object that represents the empty value.

Constructor Summary

Constructors

Constructor	Description
EmptyFormat(Format delegate)	Constructs an EmptyFormat that wraps the given mandatory format to convert null to the empty string and vice versa.
EmptyFormat(Format delegate, Object emptyValue)	Constructs an EmptyFormat that wraps the given mandatory format to convert the given emptyValue to the empty string and vice versa.

Method Summary

Modifier and Type	Method	Description
StringBuffer	format(Object obj, StringBuffer toAppendTo, FieldPosition pos)
final AttributedCharacterIterator	formatToCharacterIterator(Object obj)
Object	parseObject(String source)
final Object	parseObject(String source, ParsePosition pos)

Methods inherited from class java.text.Format

clone, format

Methods inherited from class java.lang.Object

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

Field Details

delegate

private final Format delegate

Refers to the wrapped Format that is used to forward #format and #parseObject.

emptyValue

private final Object emptyValue

Holds the object that represents the empty value. The result of formatting this value is the empty string; the result of parsing an empty string is this object.

Constructor Details

EmptyFormat

public EmptyFormat(Format delegate)

Constructs an EmptyFormat that wraps the given mandatory format to convert null to the empty string and vice versa.

Parameters:

delegate - the format that handles the standard cases

Throws:

NullPointerException - if delegate is null

EmptyFormat

public EmptyFormat(Format delegate,
 Object emptyValue)

Constructs an EmptyFormat that wraps the given mandatory format to convert the given emptyValue to the empty string and vice versa.

Parameters:

delegate - the format that handles non-null values

emptyValue - the representation of the empty string

Throws:

NullPointerException - if delegate is null

Method Details

format

public StringBuffer format(Object obj,
 StringBuffer toAppendTo,
 FieldPosition pos)

If obj is equal to the emptyValue, toAppendTo is returned. Otherwise the format is forwarded to the delegate.

Specified by:

format in class Format

parseObject

public Object parseObject(String source)
                   throws ParseException

If source is empty or whitespace, the emptyValue is returned. Otherwise parsing is forwarded to the delegate.

Overrides:

parseObject in class Format

Throws:

ParseException

parseObject

public final Object parseObject(String source,
 ParsePosition pos)

Specified by:

parseObject in class Format

formatToCharacterIterator

public final AttributedCharacterIterator formatToCharacterIterator(Object obj)

Overrides:

formatToCharacterIterator in class Format