org.apache.commons.beanutils.converters
Class AbstractConverter
java.lang.Object
org.apache.commons.beanutils.converters.AbstractConverter
- Converter
public abstract class AbstractConverter
extends java.lang.Object
Base
Converter
implementation that provides the structure
for handling conversion
to and
from a specified type.
This implementation provides the basic structure for
converting to/from a specified type optionally using a default
value or throwing a
ConversionException
if a
conversion error occurs.
Implementations should provide conversion to the specified
type and from the specified type to a
String
value
by implementing the following methods:
convertToString(value)
- convert to a String
(default implementation uses the objects toString()
method).convertToType(Class, value)
- convert
to the specified type
$Revision: 555824 $ $Date: 2007-07-13 01:27:15 +0100 (Fri, 13 Jul 2007) $private static String | DEFAULT_CONFIG_MSG - Debug logging message to indicate default value configuration
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private static String | PACKAGE - Current package name
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private Class | defaultType - The default type this
Converter handles.
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private Object | defaultValue - The default value specified to our Constructor, if any.
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private Log | log - Logging for this instance.
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private boolean | useDefault - Should we return the default value on conversion errors?
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AbstractConverter(Class defaultType) - Construct a Converter that throws a
ConversionException if an error occurs.
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AbstractConverter(Class defaultType, Object defaultValue) - Construct a Converter that returns a default
value if an error occurs.
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Object | convert(Class type, Object value) - Convert the input object into an output object of the
specified type.
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protected Object | convertArray(Object value) - Return the first element from an Array (or Collection)
or the value unchanged if not an Array (or Collection).
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protected String | convertToString(Object value) - Convert the input object into a String.
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protected abstract Object | convertToType(Class type, Object value) - Convert the input object into an output object of the
specified type.
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protected Object | getDefault(Class type) - Return the default value for conversions to the specified
type.
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protected Class | getDefaultType() - Return the default type this
Converter handles.
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protected Object | handleError(Class type, Object value, Throwable cause) - Handle Conversion Errors.
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protected Object | handleMissing(Class type) - Handle missing values.
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boolean | isUseDefault() - Indicates whether a default value will be returned or exception
thrown in the event of a conversion error.
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(package private) Log | log() - Accessor method for Log instance.
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(package private) Class | primitive(Class type) - Change primitve Class types to the associated wrapper class.
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protected void | setDefaultValue(Object defaultValue) - Set the default value, converting as required.
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String | toString() - Provide a String representation of this converter.
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(package private) String | toString(Class type) - Provide a String representation of a
java.lang.Class .
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DEFAULT_CONFIG_MSG
private static final String DEFAULT_CONFIG_MSG
Debug logging message to indicate default value configuration
PACKAGE
private static final String PACKAGE
Current package name
defaultType
private Class defaultType
The default type this Converter
handles.
defaultValue
private Object defaultValue
The default value specified to our Constructor, if any.
log
private Log log
Logging for this instance.
useDefault
private boolean useDefault
Should we return the default value on conversion errors?
AbstractConverter
public AbstractConverter(Class defaultType)
Construct a Converter that throws a
ConversionException
if an error occurs.
defaultType
- The default type this Converter
handles
AbstractConverter
public AbstractConverter(Class defaultType,
Object defaultValue)
Construct a Converter that returns a default
value if an error occurs.
defaultType
- The default type this Converter
handlesdefaultValue
- The default value to be returned
if the value to be converted is missing or an error
occurs converting the value.
convert
public Object convert(Class type,
Object value)
Convert the input object into an output object of the
specified type.
- convert in interface Converter
type
- Data type to which this value should be convertedvalue
- The input value to be converted
convertArray
protected Object convertArray(Object value)
Return the first element from an Array (or Collection)
or the value unchanged if not an Array (or Collection).
N.B. This needs to be overriden for array/Collection converters.
value
- The value to convert
- The first element in an Array (or Collection)
or the value unchanged if not an Array (or Collection)
convertToString
protected String convertToString(Object value)
throws Throwable
Convert the input object into a String.
N.B.This implementation simply uses the value's
toString()
method and should be overriden if a
more sophisticated mechanism for
conversion to a String
is required.
value
- The input value to be converted.
- the converted String value.
convertToType
protected abstract Object convertToType(Class type,
Object value)
throws Throwable
Convert the input object into an output object of the
specified type.
Typical implementations will provide a minimum of
String --> type
conversion.
type
- Data type to which this value should be converted.value
- The input value to be converted.
getDefault
protected Object getDefault(Class type)
Return the default value for conversions to the specified
type.
type
- Data type to which this value should be converted.
- The default value for the specified type.
getDefaultType
protected Class getDefaultType()
Return the default type this Converter
handles.
- The default type this
Converter
handles.
handleError
protected Object handleError(Class type,
Object value,
Throwable cause)
Handle Conversion Errors.
If a default value has been specified then it is returned
otherwise a ConversionException is thrown.
type
- Data type to which this value should be converted.value
- The input value to be convertedcause
- The exception thrown by the convert
method
handleMissing
protected Object handleMissing(Class type)
Handle missing values.
If a default value has been specified then it is returned
otherwise a ConversionException is thrown.
type
- Data type to which this value should be converted.
isUseDefault
public boolean isUseDefault()
Indicates whether a default value will be returned or exception
thrown in the event of a conversion error.
true
if a default value will be returned for
conversion errors or false
if a ConversionException
will be thrown.
log
(package private) Log log()
Accessor method for Log instance.
The Log instance variable is transient and
accessing it through this method ensures it
is re-initialized when this instance is
de-serialized.
primitive
(package private) Class primitive(Class type)
Change primitve Class types to the associated wrapper class.
type
- The class type to check.
setDefaultValue
protected void setDefaultValue(Object defaultValue)
Set the default value, converting as required.
If the default value is different from the type the
Converter
handles, it will be converted
to the handled type.
defaultValue
- The default value to be returned
if the value to be converted is missing or an error
occurs converting the value.
toString
public String toString()
Provide a String representation of this converter.
- A String representation of this converter
toString
(package private) String toString(Class type)
Provide a String representation of a java.lang.Class
.
type
- The java.lang.Class
.
- The String representation.
Copyright (c) 2001-2007 - Apache Software Foundation