com.abstractics.utils.converter
Class DefaultingConverterWrapper

java.lang.Object
  com.abstractics.utils.converter.DefaultingConverterWrapper

All Implemented Interfaces:

ObjectConverter

public class DefaultingConverterWrapper

extends java.lang.Object

implements ObjectConverter

An instance of ObjectConverter that can wrap another ObjectConverter and provide a default value if the wrapped converter's conversion fails. An example is the ConverterImageIcon class that is often wrapped to provide a default "missing image" icon when conversion fails.

 ConvertObject.register(new DefaultingConverterWrapper(new ConverterImageIcon(),
 		someImage));
 

When an object is asked to be converted, it is passed to the wrapped converter's com.abstractics.utils.converter.ObjectConverter#convert(Object) method. If that method throws an ObjectConverterException then the default value is returned, instead of throwing the exception.
NOTE: For obvious reasons, it is important that the default value is of the correct class type for the wrapped converter.

Version:

$Id: DefaultingConverterWrapper.java,v 1.1 2005/10/26 15:18:21 andrew Exp $

Author:

Andrew Lawrence, Copyright 2006 Abstractics, L.L.C., Licensed under the Apache License, Version 2.0

Constructor Summary

DefaultingConverterWrapper(ObjectConverter wrappedConverter, java.lang.Object defaultValue)
Defaults logging to true

Method Summary

java.lang.Object	convert(java.lang.Object obj, java.util.Locale locale)
java.lang.Class	getClassToConvertTo()

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultingConverterWrapper

public DefaultingConverterWrapper(ObjectConverter wrappedConverter,
                                  java.lang.Object defaultValue)

Defaults logging to true

Parameters:

wrappedConverter - The ObjectConverter object to wrap, intercepting its calls

defaultValue - The value to return if conversion results in an ObjectConverterException. Make sure this object is an instance of the correct class.

Method Detail

getClassToConvertTo

public java.lang.Class getClassToConvertTo()

Specified by:

getClassToConvertTo in interface ObjectConverter

Returns:

The class that this converter converts to

convert

public java.lang.Object convert(java.lang.Object obj,
                                java.util.Locale locale)
                         throws ObjectConverterException

Specified by:

convert in interface ObjectConverter

Parameters:

obj - Object to be converted. Guaranteed not to be null and not to already be an instanceof the Class returned by ObjectConverter.getClassToConvertTo(). Those conditions are checked before the converter is even called.

locale - The locale that is asking for the conversion. This may or may not be necessary for the conversion.

Returns:

The converted object - should NEVER return anything that is not an instanceof the class returned by ObjectConverter.getClassToConvertTo()

Throws:

ObjectConverterException - Throw this exception if the string cannot be converted, for whatever reason.